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Q: What are the forms of S-LEC? ⇓⇑ A: S-LEC is a powdered resin with good toughness, strong adhesion, and excellent dispersibility. S-LEC is non-toxic, odorless, colorless, and transparent. It can be dissolved in solvents or formed into films, thus it can be processed by various methods and applied in a wide range of fields.   Q: What are the forms of S-LEC? ⇓⇑ A: The standard form of S-LEC is a white powder, but it is also available in granular and liquid forms. The availability of different grades of S-LEC varies. Please contact our company for details.   Q: How to use S-LEC?                                                                                                                    ⇓⇑ A:The most common use is to dissolve S-LEC in organic solvents and mix it with various powders (such as inorganic powders and pigments). It can also be melted by heating. Through heating processes, S-LEC can be made into sheets or ued as a raw material for adhesives.   Q: Which solvents can S-LEC dissolve in? ⇓⇑ A: S-LEC is soluble in a variety of solvents, such as alcohols, esters, ketones, and aromatic solvents. The types of solvents that S-LEC can dissolve in vary depending on its grade.   Q: What are the benefits of using S-LEC?  ⇓⇑ A: S-LEC improves coating toughness, enhances adhesion to other materials, and achieves uniform dispersion in solutions such as pastes and inks. Furthermore, it offers a variety of unique benefits that aid in product development.   Q: What products are S-LEC used in? ⇓⇑ A: S-LEC can be used as an interlayer film in laminated glass, a ceramic adhesive, and a printed circuit board adhesive, as well as in paints, inks, and many other products.   Q: How does S-LEC differ from other resins? ⇓⇑ A: The most distinctive feature of S-LEC is the simultaneous presence of both polar and non-polar groups in its resin. This unique structure allows for customized processing to meet specific customer application requirements.   Q: What is the specific impact of hydroxyl content on water resistance/chemical resistance? ⇓⇑ A: Higher hydroxyl content (e.g., S-LEC B BX-1, S-LEC B BX-L) results in stronger resin polarity, slightly increasing water sensitivity, but leading to stronger adhesion to polar substrates such as glass and metals. Grades with low hydroxyl content (such as S-LEC B BM-1, S-LEC B BM-5) exhibit stronger hydrophobicity, resulting in better water and chemical resistance.   Q: What are the storage and shelf-life requirements for S-LEC? ⇓⇑ A: S-LEC resin should be stored in a dry, cool, and well-ventilated place, avoiding direct sunlight and moisture. The packaging should be tightly sealed. Specific shelf-life details should be found in the property data sheet for the corresponding grade, but it can typically last for several years under proper storage conditions.   Q: Will S-LEC decompose or yellow at high temperatures? ⇓⇑ A: S-LEC has good thermal stability. However, during high-temperature processing (typically referring to sintering or extrusion), it is essential to ensure operation within the recommended temperature range. Its low combustion residue is a key advantage when used in adhesives requiring complete burnout, but prolonged exposure to extremely high temperatures before sintering should be avoided to prevent initial degradation.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Polyvinyl butyral resin S-LEC B and polyvinyl acetal resin S-LEC K are among the most widely used and reliable polymer materials in today's industrial fields. The success of these materials comes from their special chemical structure. It's a careful mix of hydroxyl groups, which help with adhesion and reactivity, and acetal units, which add flexibility and water resistance to the molecular chain. Because of this balance, they can be used as either thermoplastic or thermosetting resins. They are important in many industries, including electronics, cars, coatings, and printing. 1. Electronics and Energy Sector In precision manufacturing, many materials need temporary binders to hold their shape before the final molding process. After molding, these binders have to fully break down and evaporate when exposed to high heat. S-LEC B/K resins are a good option for this purpose because they mix well, stick properly, and their thermal decomposition can be controlled. ♣ Ceramic and Metal Powder Binders Applications: Molding of ceramic or metal powders in flat panel displays (FPDs), solar cells, and various electronic components. Value: As a powder binder, S-LEC B/K effectively disperses particles and provides good dimensional stability, ensuring the integrity of the green body structure before sintering. The resin decomposes cleanly during high-temperature sintering, according to thermogravimetric analysis. Decomposition mainly happens between 300°C and 500°C. This prevents leftover material from negatively impacting the final performance of the electronic parts. Specific Grades: Specific S-LEC B grades with high molecular weights are advised for this use because of their strong film durability and bond. ♣ Printed Circuit Board Adhesives S-LEC B/K resins are typically used in combination with thermosetting resins such as phenolic resins as adhesives between printed circuit board prepregs and copper foil. Their contributions include: Flexibility and Solderability: The flexibility provided by S-LEC B/K improves the stress absorption capacity of the cured resin system, helping to enhance the adhesive layer's resistance to thermal shock and ensuring excellent peel resistance. High Tg Advantage: In PWB applications with extremely high heat resistance requirements, the high glass transition temperature (Tg) grades of S-LEC K (e.g., S-LEC K KS-5 or S-LEC K KS-10) are even more important, providing the necessary thermal stability to withstand subsequent processing temperatures.   2. Coatings and Varnishes S-LEC B/K resin is also useful in coatings and varnishes because it sticks well to many surfaces like metals, plastics, and glass. Also, it works well with other resins for crosslinking, which is a key advantage. ♣ Wash Primer Main Function: This is one of the most classic applications of S-LEC B/K. It is a pretreatment primer for metals such as steel and aluminum, effectively improving the adhesion of subsequent topcoats to the metal surface and providing short-term rust protection. Applications: Widely used in structural components requiring underlying protection, such as ships, bridges, automotive refinish paints, and rail vehicles. Formulation Advantages: S-LEC B/K shows great compatibility by creating strong bonds with many topcoats, such as those made from PVC, melamine, or oil-based phenolic coatings. ♣ Metallic Varnishes and Baking Coatings S-LEC B/K, when mixed with phenolic resin pre-condensate, can be used to create high-quality baking coatings for food containers. Its addition significantly improves the toughness, adhesion, and service durability of the coating. In metal foil varnishes, this resin provides a transparent, flexible protective layer. ♣ Leather Coatings S-LEC B grades, due to their unique chemical structure, offer high flexibility and low-temperature impact resistance, making them particularly suitable for leather coatings. Leather surfaces coated with S-LEC B resin exhibit excellent elongation at room temperature, with no significant loss of performance even at low temperatures, forming a soft and resilient film on the leather.   3. Printing Inks In the printing ink field, S-LEC B/K resin acts as a pigment binder and dispersant, suitable for flexographic and gravure printing. Key Properties: Grades suitable for inks are typically low-viscosity S-LEC B/K, such as S-LEC B BL-10. Function: The resin ensures uniform dispersion of pigments in solvents and provides strong adhesion to substrates (such as plastic films) after ink curing. Its non-toxic and odorless properties make it advantageous in food packaging and applications where odor is critical.   4. Specialized Adhesive Applications Besides its application in PWB (Polarization and Welding), S-LEC B/K is also used as a key adhesive, either alone or in combination with other materials. ♣ Enamelled Coil Bonding Dipping or coating the enameled wire of a coil with an S-LEC B/K solution and then heating to melt or cure the resin achieves strong bonding and fixation between conductors. This is used in the manufacture of coils for motors and transformers, improving structural stability and insulation. ♣ Adhesive Formulation Substrates S-LEC B/K has hydroxyl groups in its structure, which allows it to cross-link with materials like isocyanates or epoxy resins. This process creates composite adhesives that have good heat resistance, toughness, and adhesive properties.   5. Other Miscellaneous Applications The versatility of S-LEC B/K resin also makes it play an important role in many niche professional fields. ♣ Reflective Film Adhesive In the manufacture of reflective films (such as road traffic signs), S-LEC B/K serves as an adhesive for the reflective layer of glass beads. Its advantages lie in its high film transparency, excellent dispersion of pigments (such as aluminum powder), and strong adhesion to plastic films such as PET. ♣ Magnetic Recording Tape Coating The resin exhibits excellent dispersibility and adhesion to magnetic powders, making it suitable for use as a magnetic powder coating adhesive in advanced magnetic recording tapes (such as audio and video tapes). ♣ Dye Transfer Ribbon Inks In sublimation transfer technology, S-LEC B/K resin is used to manufacture dye inks due to its excellent dispersibility for sublimated dyes.   The S-LEC B/K resin series has found widespread use in modern industry because its chemical structure can be modified to provide good adhesion, crosslinking, flexibility, and a wide glass transition temperature range. S-LEC B is used in both flexible and traditional coatings, while S-LEC K is used in high glass transition temperature electronic adhesives. These resins are important high-performance materials that help to advance industrial innovation and improve products.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

S-LEC B and S-LEC K are types of polymers that work well in coatings, adhesives, and electronics. They can handle many different and difficult jobs because of how their molecules are arranged. Specifically, their solubility and how they handle heat are carefully managed. 1. Solubility Characteristics: The Structural Basis for Solvent Selection S-LEC B/K resins are quite soluble, dissolving in alcohols, esters, ketones, and aromatics, especially well in alcohols. Solubility differences among grades show variations in their chemical makeup. 1.1 The Mechanism of Structure's Influence on Solubility Solubility is primarily constrained by the contradictory relationship between the hydroxyl content and acetal content on the resin molecular chain. Hydroxyl Content: Hydroxyl groups exhibit polarity; resins with a greater amount of hydroxyl content show increased hydrophilicity and polarity. Because of this, the resin will dissolve better in polar solvents like alcohols and become more reactive with thermosetting resins. Still, too much hydroxyl content can make the resin less flexible and more vulnerable to water damage. Acetal Content: Acetal units are nonpolar groups. The higher the acetal content, the more pronounced the nonpolar characteristics of the resin. This makes it more soluble in nonpolar solvents and improves its flexibility, water resistance, and compatibility with other nonpolar resins. 1.2 Solubility Differences Between Models Analysis of the solubility table reveals different solvent preferences for different models: S-LEC B low molecular weight, high hydroxyl grades (e.g., S-LEC B BL-1): These grades have a high hydroxyl content (e.g., BL-1H has a hydroxyl content of approximately 30 mol%), therefore exhibiting complete solubility in most alcohol solvents (e.g., methanol, ethanol, isopropanol) and strongly polar solvents (e.g., N,N-dimethylformamide). S-LEC K high Tg grades (e.g., S-LEC K KS-1): S-LEC K resins are designed to provide high thermal stability, and their molecular structure can be more tightly packed. Some KS grades, though still polar due to their hydroxyl content (around 25 mol%), either swell or partially dissolve in alcohols like methanol and ethanol. This suggests the acetal structure affects how well these polar solvents wet the molecules. This behavior shows the distinct properties of their chemical composition. 1.3 Advantages of Mixed Solvents One characteristic of S-LEC B/K is that it allows for a wider range of water tolerance in solvents. Furthermore, using mixed solvents generally produces better dissolution results because: Reduced viscosity: Mixed solvents help reduce the overall viscosity of the solution, facilitating application handling. Storage stability: Mixed solvents help maintain stable solution viscosity, which is beneficial for long-term storage. Optimized solubility: The polar/non-polar balance of the mixed solvents allows for more effective wetting of the three structural units of the resin.   2. Thermodynamic Properties: The Dominant Role of Tg and Softening Point The thermal properties, like the glass transition temperature (Tg) and softening point, are key to how well a resin holds up and can be molded at high temperatures. The S-LEC B/K series comes in a variety of Tg values, ranging from 59°C to 110°C. This allows them to be used in situations requiring flexibility at low temperatures or heat resistance when things get hot. 2.1 Structural Differences in Glass Transition Temperature (Tg) S-LEC K (High Tg Type): S-LEC K resin utilizes shorter acetaldehyde side chains (R:CH3), resulting in a denser molecular chain packing and achieving the highest Tg value in the series. For example, both KS-3 and KS-5 can reach a Tg of 110°C, making them ideal materials for applications requiring high thermal stability, such as bonding electronic components. S-LEC B (General Purpose and Flexible Type): S-LEC B employs longer butyraldehyde side chains (R: -CH2CH2CH3), increasing the spacing between molecular chains and free volume, resulting in a relatively low Tg. For example, BL-10 has a Tg of only 59℃. This lower Tg endows S-LEC B with excellent toughness and flexibility, exhibiting outstanding impact resistance at low temperatures. 2.2 Synergistic Effect of Tg and Molecular Weight On the Tg graph (Figure 9), the Tg of the same acetal type (e.g., S-LEC B) generally shows a slight increasing trend with increasing molecular weight. For example, the Tg range of medium molecular weight grades (e.g., BM-1) and high molecular weight grades (e.g., BH-3) is roughly between 60℃ and 70℃. Higher molecular weight contributes to improved thermodynamic stability of the polymer. 2.3 Softening Point The softening point is an important indicator for measuring the hot melting behavior of resins. The softening point diagram (Figure 10) shows that the S-LEC B/K grades have a wide softening point range, from approximately 100°C to over 200°C. Consistent with the Tg trend, high Tg grades of S-LEC K, such as KS-5, can achieve softening points above 200°C, giving this resin a significant advantage in hot-melt applications and high-temperature processing.   3. Thermal Decomposition Behavior: TG Analysis Insights Thermogravimetric analysis (TG) is used to study the mass loss of resins during heating, revealing their thermal decomposition characteristics. TG analysis of S-LEC B grades (e.g., BM-S and BM-2) shows differences under different atmospheres: Inert Atmosphere (N2): Under nitrogen, the resin exhibits a relatively simple and rapid mass loss process. Decomposition typically begins around 350°C and completes major decomposition around 450°C. Oxidizing Atmosphere (Air): Under air, the decomposition process typically presents a multi-stage mass loss curve. The first stage of decomposition occurs between 300°C and 400°C, followed by a second stage of oxidative decomposition at approximately 450°C to 550°C, ultimately potentially leading to complete combustion.   The solubility and thermodynamic properties of S-LEC B and S-LEC K resins form the basis for their versatile applications. By precisely controlling the side chains (butyraldehyde and acetaldehyde) of the acetal units, as well as the ratio of hydroxyl groups to molecular weight, this series of resins achieves the following objectives: Solubility: Solvent mixtures balance polar (hydroxyl) and non-polar (acetal) characteristics to suit different coating types. Mixing solvents helps reach the required application viscosity. Thermodynamic Properties: Flexible switching between the high Tg of S-LEC K (up to 110°C) and the low Tg of S-LEC B (down to 59°C) ensures a wide range of applications, from low-temperature flexibility to high-temperature heat resistance.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

High-performance resins hold a unique position in the landscape of modern industrial materials due to their superior comprehensive properties. Among many similar products, polyvinyl butyral resins S-LEC B and S-LEC K, with their unique and flexible chemical structures, have become key solutions in fields ranging from high-precision electronics manufacturing to specialty coatings. S-LEC B was first introduced in the 1930s, initially used in industry as an interlayer film for safety glass, establishing its position among high-performance polymers. S-LEC K, as a functional extension of this series, focuses on applications with stringent requirements for heat resistance due to its high glass transition temperature (Tg). Although both are collectively referred to as the S-LEC B/K series, their performance differences are rooted in their sophisticated chemical structure design.   1. Core Chemical Structure: The Source of Performance Both S-LEC B and S-LEC K are derived from polyvinyl alcohol (PVA). These are prepared by reacting PVA with specific aldehydes in a reaction called acetalization. Due to limitations in the manufacturing process, the acetalization reaction cannot be completed completely, resulting in the final resin molecular chain retaining three crucial structural units that collectively determine the final product's properties:     ♠Acetal Unit: This is the core functional unit of the resin, imparting hydrophobicity and flexibility to the material. The fundamental difference between S-LEC B and S-LEC K lies in the side chain (R group) of this unit: S-LEC B: The aldehyde group R used in acetalization is -CH2CH2CH3. The longer side chain gives S-LEC B superior flexibility and solubility in nonpolar solvents. S-LEC K: The aldehyde group R used in acetalization is -CH3. The shorter side chain results in a more compact packing of molecular chains, giving S-LEC K a higher glass transition temperature (Tg) and better thermal stability. ♣Hydroxyl Unit (OH):The unit refers to the part of PVA that hasn't reacted and remains within the resin molecule in a specific ratio. The hydroxyl group gives the resin good adhesion—particularly to polar surfaces like metals and glass—and makes it attract water. More crucially, this hydroxyl group lets the resin form cross-links with resins that harden when heated, like epoxy resins and isocyanates. This hardening broadens the resin's use. ♣Acetyl Unit: These trace units remain because of incomplete breakdown during PVA production. The proportions of these three units in the molecular chain, precisely controlled through the manufacturing process, constitute the vast spectrum of the S-LEC B/K series resin grades.   2. Performance Regulation: A Precise Balance of Influencing Factors The physical and chemical properties of this series of resins are not fixed but are precisely regulated by the following three core factors: 2.1 The Unity of Opposites and Hydroxyl Content The acetal and hydroxyl content in the molecular structure usually exhibit an inverse relationship, and their balance directly determines the key properties of the resin: Flexibility and Water Resistance: The higher the acetal content, the more pronounced the non-polar characteristics of the resin, the better the flexibility, water resistance, and compatibility with non-polar resins. Adhesion and Reactivity: The amount of hydroxyl groups present strongly affects how well a resin sticks, particularly when polar adsorption is needed. At the same time, the hydroxyl content also influences how the resin reacts with thermosetting resins and how easily it dissolves in polar solvents. 2.2 The Decisive Role of Molecular Weight in Application Performance The molecular weight (degree of polymerization) of the resin directly affects the following crucial application characteristics: Film Toughness: The higher the molecular weight, the stronger the toughness of the film or coating made from the resin. Solution Viscosity: Molecular weight is the main factor affecting solution viscosity. At a given solids content, higher molecular weight grades offer higher solution viscosity, making them suitable for certain thickening or high-viscosity applications. Adhesion: Molecular weight also significantly impacts final adhesive strength. The S-LEC B/K series offers a wide molecular weight range, from approximately 14,000 to 130,000. Engineers can choose materials based on the needed viscosity, strength, and flexibility by picking different acetal contents. 2.3 Thermodynamic Properties: Tg and Heat Resistance Stability The glass transition temperature (Tg) is a core indicator of a material's heat resistance. This series of resins covers a Tg range from 59°C to 110°C, enabling them to meet the needs of applications ranging from low-temperature applications requiring high flexibility to high-temperature applications requiring high stability: Advantages of S-LEC K: S-LEC K acetal resins, such as S-LEC K KS-1, S-LEC K KS-5, and S-LEC K KS-10, usually show the highest glass transition temperature (Tg), reaching up to 110°C. This makes them good for uses needing high heat resistance and a high softening point—some types can reach 200°C. Examples include bonding printed circuit boards and in difficult electronic parts. Advantages of S-LEC B: S-LEC B acetal resins, which have lower glass transition temperatures, provide good impact resistance at low temperatures and increased flexibility.   3. Functional Expansion: Crosslinking Reaction and Thermosetting Potential     The S-LEC B/K series is not limited to use as a thermoplastic material. Because it has many hydroxyl groups, this substance can crosslink and cure when mixed with different thermosetting resins like phenolic resins, epoxy resins, or isocyanates. This crosslinking capability is a significant advantage in industrial applications, allowing engineers to combine the superior toughness, adhesion, and flexibility of thermoplastic resins with the high heat resistance, chemical resistance, and mechanical strength of thermosetting resins through formulation design. The result is composite materials that perform well, overcoming the limits of single resins. For instance, this crosslinking and curing process is key to achieving the needed performance in high-end coatings and adhesives.   S-LEC B and S-LEC K resins are important types of high-performance polymers. These resins are valued because their properties, like flexibility and adhesion, can be adjusted. This is achieved by carefully managing the acetal side chains (using butyraldehyde or acetaldehyde) and the amount of hydroxyl content in the resin. This meticulous control over molecular structure ensures that S-LEC B/K can continuously provide high-performance material solutions for multiple key industrial sectors, including electronics, automotive, coatings, and adhesives.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

1. Chemical Nature and Key Performance Indicators of Primary Dispersants Suspension polymerization is a primary manufacturing method for polyvinyl chloride (PVC). Ensuring the uniform and stable dispersion of monomer droplets in an aqueous medium is crucial, directly determining the morphology, particle size distribution, and application performance of the final PVC resin particles. The key additive for achieving this goal is the primary dispersant.   1.1 What is a Primary Dispersant? Primary dispersants typically use polyvinyl alcohol (PVA), a water-soluble polymer compound. It is produced through a specific hydrolysis process and is specifically developed for vinyl chloride suspension polymerization systems. The role of PVA as a primary dispersant is mainly to form a protective layer at the interface between vinyl chloride monomer droplets and the aqueous phase, thereby preventing the monomer droplets from agglomerating into large clumps during polymerization and ensuring the formation of uniform and independent PVC particles. 1.2 Key Performance Indicators: Degree of Hydrolysis and Molecular Weight  The performance and effectiveness of polyvinyl alcohol as a primary dispersant are mainly determined by two core technical parameters: the degree of hydrolysis and molecular weight (usually measured by the viscosity of the aqueous solution). Precise control of these indicators is achieved through specialized manufacturing processes. Degree of Hydrolysis Definition and Range: The degree of hydrolysis is the molar percentage (mole%) of vinyl acetate groups converted to alcohol groups in a polyvinyl alcohol molecule. Products with different degrees of hydrolysis are developed to meet the needs of different PVC applications. For example, the degree of hydrolysis in Alcotex's product line ranges from a low end of 71.5-73.5 mole% to 86.7-88.7 mole%. Impact on PVC Products: The degree of hydrolysis is a key factor determining the interfacial activity and solubility of polyvinyl alcohol. It affects the bulk density, porosity, and particle size distribution of the final PVC particles. For example, one product with a degree of hydrolysis of 76.0-79.0 mole% helps to produce a denser PVC with slightly lower porosity than a product with a degree of hydrolysis of 71.5-73.5 mole%. Molecular Weight (Viscosity) Measurement Standard: In technical data sheets, molecular weight is typically expressed by the viscosity (mPa.s) of a 4% aqueous solution of the product at 20°C. Classification and Characteristics: Dispersant products can be classified into low/medium molecular weight and high molecular weight based on their molecular weight. Low/Medium Molecular Weight Products: For example, products with a viscosity range of 5.5-6.6 mPa.s. High Molecular Weight Products: For example, products with a viscosity range of 36-52 mPa.s. The molecular weight (viscosity) directly affects the strength and efficiency of the protective layer formed by polyvinyl alcohol at the interface. 1.3 Key Technical Parameter Comparison Table Property Appearance Ash Content(%) Degree of Hydrolysis (mole %) Total Solid Content (%) Viscosity (mPa.s) ALCOTEX 72.5 Off white to pale yellow granules 0.5 max 71.5 - 73.5 > 95.0 5.6 - 6.6 ALCOTEX 7206 Off white to pale yellow granules 0.5 max 71.5 - 73.5 > 95.0 5.6 - 6.6 ALCOTEX 78 Off white to pale yellow granules 0.5 max 76.0 - 79.0 ≥95.0 5.6 - 6.5 ALCOTEX 80 White granular solid 0.5 max 78.5 - 81.5 > 95.0 36 - 42 ALCOTEX 8048 White granular solid 0.5 max 78.5 - 81.5 > 95.0 44 - 52 ALCOTEX 8847 White granular solid 0.5 max 86.7 - 88.7 > 95.0 45 - 49   2. Advantages of Using High-Quality Primary Dispersants in PVC Production Selecting and using high-quality primary dispersants, such as products with specific hydrolysis degrees and molecular weights (viscosities), can bring significant production benefits and improved product quality to PVC manufacturers. 2.1 Increased Plant Capacity and Reduced Operating Costs Using efficient primary dispersants helps optimize the polymerization reaction, directly affecting plant output and cost-effectiveness. Reduced reactor scaling: High-quality dispersants effectively stabilize monomer droplets, minimizing polymer deposition (scaling) on the reactor walls. Reduced scaling means shorter cleaning downtime, significantly improving reactor uptime and capacity. Optimized dispersant dosage: In some products, the desired particle size distribution can be achieved with lower dosages. This directly reduces raw material costs and may simplify the removal of residual additives. High bulk density: Some products contribute to the production of PVC granules with high bulk density. High bulk density products are more efficient in transportation and storage, and may also lead to better performance in downstream processing. 2.2 Improving the final quality of PVC polymers The primary dispersant has a decisive influence on the microstructure and macroscopic properties of PVC granules. Wide range of particle size, porosity, and bulk density adjustment: Different primary dispersant products can produce PVC resins with a wide range of porosities and bulk densities. This flexibility allows manufacturers to tailor product performance to the specific requirements of the end application. For example, some low molecular weight products can produce highly porous particles, which facilitates the removal of free monomers. Optimized particle morphology and flow characteristics: PVC particles produced using optimized primary dispersants tend to be more spherical. Spherical particles, combined with higher packing density, achieve optimal flow characteristics while maintaining minimal reduction in porosity, which is highly beneficial for powder transport and mixing in downstream equipment. Rapid plasticizer absorption: By adjusting the dispersant formulation, the plasticizer absorption characteristics of PVC particles can be precisely controlled, achieving rapid drying times, which is crucial for the processing of flexible PVC (such as cables and films).   3. Product Preparation, Transportation, and Storage Requirements Proper handling, storage, and preparation of primary dispersants are essential for maintaining product quality and ensuring the stability of the polymerization process. 3.1 Solution Preparation and Precautions In most applications, polyvinyl alcohol primary dispersants are used in aqueous solution form. Dissolution Process: The main dispersant is typically added to cold water and stirred first, then heated to 85-95°C (using a water bath or steam jet) until the material is completely dissolved. Defoaming Measures: Polyvinyl alcohol solutions may generate foam during stirring or pumping. To reduce foaming, it is recommended to use suitable stirring equipment, such as a slow anchor mixer, or avoid using vertical or near-vertical pipe slopes. Biological Contamination: If polyvinyl alcohol aqueous solutions are stored at high temperatures for extended periods, they are susceptible to mold and bacteria. Therefore, the storage conditions and time of the solution should be properly managed. 3.2 Transportation and Storage Conditions The physical form of the product is usually granular solid, packaged in paper or plastic bags. Storage Environment: The product should be stored indoors, away from humid areas and open flames. Moisture intrusion must be prevented to maintain product quality. Shelf Life and Testing Recommendations: Under original supply conditions, the product typically has a usable period of 24 months from the date of manufacture. Beyond this period, the product may still be usable, but testing is recommended. Materials stored for more than 12 months after delivery are recommended to be tested before being put into use. Safety Tip: Always read the product's safety data sheet before handling it for recommendations on safe handling, use, and disposal. Primary dispersants, especially those based on polyvinyl alcohol (PVA), are essential additives in PVC suspension polymerization. By precisely controlling their degree of hydrolysis and molecular weight, manufacturers can improve reactor efficiency, reduce operating costs, and produce PVC resins with specific particle sizes, bulk densities, and excellent processing properties. Correctly understanding and applying the information in these technical data sheets is a crucial step in ensuring the production of high-quality PVC products.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Since the late 1930s, polyvinyl butyral (PVB), a type of thermoplastic resin, has been key to making laminated glass. Laminated glass consists of one or more layers of PVB film (the interlayer) between two or more pieces of glass, bonded together using heat and pressure. This structure endows the finished glass with a range of unique properties, making it a crucial safety and functional material in the automotive industry and modern construction.   1. Chemical Basis and Unique Properties of PVB Resin 1.1 Structure and Synthesis PVB resin is a synthetic polymer obtained from polyvinyl alcohol (PVA) and butyral through an acetalization reaction. Its molecular chain contains three main functional groups: Butyral group: Responsible for providing the polymer with hydrophobicity, elasticity, and solubility. Hydroxy group: Maintains the polymer's strong adhesion to glass surfaces, heat resistance, and compatibility with plasticizers. Vinyl acetate group:，Usually present in small amounts, it has a fine-tuning effect on the glass transition temperature (Tg) and processing properties of PVB. This unique structure endows PVB with a range of ideal properties for laminated glass applications. 1.2 Key Physical Properties As the interlayer in laminated glass, PVB film must possess the following core physical properties: High Adhesion Strength: Strong adhesion to the glass surface ensures that glass fragments adhere firmly to the film upon impact. Excellent Elasticity and Toughness: Ability to absorb impact energy and effectively prevent penetration, forming the physical basis for the safety of laminated glass. Optical Transparency: Extremely high light transmittance in the visible light range, without affecting driver visibility or building lighting. Aging Resistance: Maintaining its mechanical and optical properties even under harsh environments such as ultraviolet radiation, humidity, and temperature variations.     2. Core Applications and Functions in Automotive Glass Automotive glass is one of the earliest and most important application markets for PVB resin. PVB plays a dual role in automotive windshields, providing both safety and functionality. CCP PVB B-18FS, combined with plasticizer 3GO and additives, can be extruded to produce various PVB interlayer films for architectural and automotive applications. 2.1 Collision Safety and Fragment Retention This is the most critical role of PVB in automotive applications. In a vehicle collision, the windshield shatters, but the PVB interlayer can: Prevent Penetration: The windshield is designed to take in impact energy. This stops things like stones from getting through the glass into the car. Plus, it keeps passengers inside the car and protects them from head injuries if they hit the glass. Fragment Retention: Firmly adhere to broken glass, preventing sharp fragments from flying and causing secondary injuries to passengers. 2.2 Noise Reduction and Sound Insulation Performance Modern cars need to be more comfortable to drive. PVB films, mostly those made in a specific way, are good at quieting high-frequency vibrations. This cuts down on wind and road noise. For instance, Changchun PVB B-17HX is made with certain plasticizers and a specific molecular weight to improve its damping abilities. It works very well for car side windows and sunroofs, where better sound insulation is needed.   3. Applications of PVB Resin in Architectural Glass Laminated glass is used in a lot of construction projects. You can find it in curtain walls, skylights, interior walls, and railings. The application of PVB resin must adapt to more stringent requirements for structural strength, durability, and climate change mitigation. 3.1 Structural Safety and Disaster Resistance The main function of laminated glass in architecture is to provide structural integrity and disaster resistance. Storm and Earthquake Resistance: In severe weather, like hurricanes, typhoons, or earthquakes, PVB laminated glass can still hold its structure even if it breaks. This helps keep people and property inside safe, because the glass doesn't collapse or fall apart. Theft and Explosion Protection: Thickened multi-layer PVB laminated glass (usually a composite structure of multiple layers of PVB and glass) has extremely high impact resistance. It can effectively resist the impact of blunt objects or gunshots and is widely used in high-security locations such as banks, jewelry stores, and museums. In the shock wave of an explosion, the PVB layer can absorb energy, preventing glass shards from injuring people. 3.2 Energy Saving, Environmental Protection, and Aesthetic Design Technological advancements in PVB films have also made them part of building energy-saving solutions. Solar Control PVB: PVB films containing special additives or dyes can regulate the transmittance and reflectance of sunlight, reducing heat entering the interior (lowering U-value and SC value), thereby reducing air conditioning energy consumption. Colors and Patterns: PVB films can be customized in a variety of colors and can even be embedded with patterns or textiles, providing architects with a wealth of facade design and aesthetic choices to meet the complex needs of modern architecture for light, privacy, and appearance. 3.3 Durability and Long-Term Performance Architectural glass must withstand decades of outdoor exposure. PVB resin possesses excellent durability: Aging Resistance: High-quality PVB films have good resistance to ultraviolet rays and moisture, ensuring that laminated glass will not yellow or delaminate during long-term use. Edge Sealing: The edge bonding strength between PVB and glass is key to preventing moisture and air penetration, which is essential for maintaining the transparency of laminated glass and preventing internal fogging.   As the automotive and construction industries increasingly demand higher standards of safety, environmental protection, and functionality, PVB resin technology is constantly evolving: ♦ Competition and Integration of Innovative Materials While PVB remains the mainstream material, new interlayer materials such as ionic polymers (e.g., SGP/Surlyn) are competing in applications requiring high structural strength and rigidity, particularly in high-rise buildings. The future trend may involve the composite use of PVB with other polymers to achieve a superior performance balance. ♦ Intelligentization and Integration Future automotive and architectural glass will be more intelligent, with PVB films serving as carriers for functional materials: Thermal Management and Electrical Heating: PVB layers can integrate micro-wires or transparent conductive materials for defogging, defrosting, or intelligent dimming of glass. Integrated Antennas and Sensors: Integrating vehicle antennas or various environmental sensors into the PVB film layer achieves high functional integration and aesthetic optimization. ♦ Sustainable Development Under environmental pressures, developing PVB resins synthesized from renewable resources or bio-based raw materials, and improving PVB recycling technologies, will be significant challenges and development directions for the industry.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

Polyvinyl chloride (PVC) is one of the most widely used plastics, and its properties largely depend on the morphology, porosity, and bulk density of the PVC particles formed during suspension polymerization. The role of the suspending agent is crucial in the suspension polymerization process. ALCOTEX series polyvinyl alcohol products are specifically developed as secondary suspending agents (or pore enhancers) to synergize with conventional primary suspending agents, jointly optimizing the microstructure and macroscopic properties of PVC resin. 1. What is an auxiliary dispersant? In complex dispersion systems, a single primary dispersant often struggles to simultaneously address multiple requirements such as wetting, depolymerization, and stabilization. This is where the role of auxiliary dispersants becomes prominent. They significantly improve the dispersion stability and flowability of the entire system by adjusting the surface tension of the system, improving the charge distribution between particles, and enhancing the adsorption capacity of the primary dispersant. In pigment systems, it reduces the risk of flocculation and sedimentation; In emulsion polymerization, it controls particle size distribution and polymerization rate; In rubber latexes, it prevents particle agglomeration and improves emulsion storage stability.   2. Comparison of Technical Characteristics of ALCOTEX Series Products Property Appearance Total Solids (%) Degree of Hydrolysis (mole %) Viscosity@23℃ (mPa.s) ALCOTEX 45 Colourless to pale straw/clear to slight haze 34.0 - 36.0 43.0 - 47.0 300 - 600 ALCOTEX 552P Slightly Yellow aqueous solution 39.5 - 40.5 54.0 - 57.0 800 - 1400 ALCOTEX 432P Water white to pale straw/clear to slight haze 39.0 - 41.0 43.0 - 46.0 100 - 180 ALCOTEX 552P Slightly Yellow aqueous solution 39.5 - 40.5 54.0 - 57.0 800 - 1400 ALCOTEX 55-002H Very pale yellow solution 38.5 - 39.5 54.0 - 57.0 1000 - 1500   High Hydrolysis Degree Products (approximately 55% mole %): 55-002H and 552P ALCOTEX 55-002H: A colloidal dispersion of polyvinyl alcohol (PVA) with a high degree of hydrolysis (54.0-57.0 mole %). Nuclear magnetic resonance (NMR) measurements show a random distribution of its acetate groups. For application, it is recommended to add a portion of the primary suspending agent before adding 55-002H to ensure good dispersion of the secondary additive. It is strictly forbidden to add it to the VCM feed line. ALCOTEX 552P: A 55% aqueous solution of hydrolyzed PVA, also with a high degree of hydrolysis. It has a low residual methanol content (<2% w/w) and a high cloud point (>45℃). It can be directly added to the reactor or pumped into a flowing water feed line. It is recommended to add 552P after adding at least a portion of the primary suspending agent.   Low degree of hydrolysis products (approximately 43%-45% mole %): WD100, 432P, and 45 ALCOTEX WD100: A 43% aqueous solution of hydrolyzed polyvinyl alcohol, characterized by extremely low methanol content (<2% w/w). It can be infinitely diluted with water. Compared to conventional products, WD100 provides higher porosity for PVC resin and reduces gel or "fisheye" formation. Unlike traditional secondary additives, WD100 can be added before the primary suspending agent, or as a stable primary/secondary suspending agent co-solution. Adding via the water feed line is recommended. ALCOTEX 432P: A low-viscosity methanol-based solution of 43% hydrolyzed polyvinyl alcohol, with the lowest viscosity in the series (100-180 mPa·s). Due to its methanol solubility, its storage and transportation must strictly comply with local regulations regarding flammability and toxicity. It is typically pumped directly into the reactor after the addition of water and the primary stabilizer. ALCOTEX 45: A 45% hydrolyzed polyvinyl alcohol (PVC) water/isopropanol solution with moderate viscosity (300-600 mPa·s). Due to the presence of isopropanol, it is also subject to local flammability regulations. Its nuclear magnetic resonance (NMR) results also show a random distribution of acetate groups. It is typically pumped into the reactor after the addition of water and the main suspending agent. All ALCOTEX products are designed to optimize the porosity/bulk density relationship, resulting in the following practical production advantages: Highly efficient VCM removal: Increased porosity allows for more thorough VCM release, permitting the use of gentler stripping conditions, potentially reducing stripping time, steam consumption, and stripping temperature. Optimized plasticizer absorption: Improves PVC's ability to absorb plasticizers, particularly beneficial for manufacturing flexible PVC products. Product consistency and design: ALCOTEX helps achieve a more uniform pore distribution and tends to make PVC particles more spherical, thus improving bulk density. This provides flexibility in polymer design, such as achieving higher conversion rates at a given porosity.   3. Conclusion  The ALCOTEX series of secondary suspending agents are powerful tools for S-PVC manufacturers to optimize product structure and improve production efficiency. By precisely controlling the degree of hydrolysis, solution form, and addition method of polyvinyl alcohol, these products can significantly improve the porosity/bulk density relationship of PVC, simplify the stripping process, and ultimately enhance the thermal stability and processing performance of the product. Manufacturers can select the most suitable secondary suspending agent from this series based on their own equipment conditions, the required PVC molecular weight range, and sensitivity to methanol/isopropanol content.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

In the vast plastics industry, the choice of polymer is crucial in determining the performance and cost of the final product. This discussion will compare two kinds of polypropylene, Braskem Polypropylene RP 225M and ADMER QB520E, which are suited for different jobs. RP 225M, a medium-flow random copolymer, sees use in film applications because of its good optical clarity and slip. QB520E, on the other hand, is a unique maleic anhydride-grafted homopolymer PP-based adhesive resin focused on adhesive applications in multilayer structures. If you're looking for the right material for flexible packaging, textile applications, or composite structures, this comparison guide will provide clear insights to help you make an informed choice.   1. Core Performance Comparison: RP 225M vs QB520E 1.1 Flowability and Density Features Braskem RP 225M ADMER QB520E Emphasis/Differences Mel Flow Rate (MFR) 8.0 g/10 min 1.8g/10min RP 225M has higher flowability, suitable for thin-walled or high-speed extrusion processes (such as films); QB520E has lower flowability, which is beneficial for improving melt strength and adhesion. Density 0.902g/cm3 0.90g/cm3 Both have very similar densities, falling within the typical polypropylene density range. 1.2 Mechanical Strength and Rigidity Features Braskem RP 225M ADMER QB520E Emphasis/Differences Tensile Yield Strength 28 MPa 24 MPa RP 225M has a slight edge in tensile strength, which may provide better load-bearing capacity in single-layer flexible packaging. Flexural Modulus 900 MPa N/A / Cantilever Impact Strength 30 J/m 470 J/m2 QB520E exhibits extremely high impact strength, consistent with its application as an adhesive layer in bottles, sheets, etc., where high toughness is required to withstand impacts. Elongation at Break 12%(Yield) 280% (Fracture) QB520E's elongation at break is significantly higher than RP 225M's yield elongation, confirming its high toughness and flexibility, ideal properties for an adhesive resin.   2. In-Depth Application Analysis: Identifying Your Needs 2.1 Braskem RP 225M: Transparency, Sliding, and Heat Sealing RP 225M is a product tailored for single-layer flexible packaging and textile applications. Key Features: Excellent Optical Properties: As a random copolymer, it inherently possesses better transparency and gloss than homopolymers, meeting the demands of high-definition packaging. Excellent Sliding Properties (Low Coefficient of Friction): Contains sliding agents and anti-blocking agents to ensure smooth operation on high-speed packaging machinery, preventing film sticking. Good Heat Sealing Properties: The lower initial heat-sealing temperature (111°C) helps improve packaging efficiency. Suitable Applications: Various flexible packaging films (flat extruded and blown films) 1717, especially for inner or middle packaging requiring high transparency and ease of handling, as well as textile applications. 2.2 ADMER QB520E: The "Glue" for Multilayer Structures QB520E is essentially an adhesive resin designed to solve the problem of direct bonding between different polymer layers. Key Characteristics: Strong Bonding: Utilizing maleic anhydride grafting technology, it can form strong chemical bonds with polar materials (such as EVOH or PA (polyamide)) and non-polar PP substrates, creating a high-barrier, high-strength multilayer structure. High Toughness: Extremely high impact strength (470 J/m²) and elongation at break ensure that the composite material will not delaminate under impact or bending. Processing Stability: Maximum processing temperature up to 300°C provides safety for multilayer co-extrusion. Applications: Primarily used in co-extrusion processes as an adhesive between PP and EVOH/PA barrier layers. Typical products include: Multilayer Barrier Bottles and Sheets: Used for packaging with high barrier requirements, such as for food and cosmetics. Multilayer Blown Films and Pipes: Ensures the integrity and durability of pipe and high-barrier film structures.   3. Production and Safety Considerations 3.1 Processing Recommendations RP 225M: Use planar film extrusion or blown film extrusion processes. High MFR is beneficial for processing. QB520E: Although it has low flowability, it does not require pre-drying, simplifying preparation for multilayer co-extrusion processes. Its melt viscosity-shear rate profile (rheological profile) helps to precisely control layer thickness in co-extrusion. Attention should be paid to the maximum temperature limit (300°C) to avoid decomposition. 3.2 Safety and Regulations RP 225M: Not recommended for packaging or products that come into contact with parenteral solutions or the human body. QB520E: Regarding food contact conditions, its components have relevant compliance statements in the EU and US FDA (as an adhesive), but the manufacturer is responsible for ensuring that the final application complies with all food contact regulations.   4. Summary and Recommendations Your final choice depends on your product structure: If you need to manufacture a single-layer packaging film with good clarity, rigidity, and slip resistance, RP 225M is ideal. If you need to manufacture a multi-layered structure (such as plastic wrap or barrier bottles) that includes a barrier layer (such as Ethylene-VinylAlcohol Copolymer (EVOH) /PA), QB520E is a key material to ensure strong adhesion and high toughness between different layers.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

One of the core challenges in the suspension polymerization process of polyvinyl chloride (PVC) is polymer scaling on the inner walls and internal components of the reactor. Scale buildup has a negative impact on reactor heat transfer and extends the time it takes for polymerization. More importantly, companies have to do expensive, high-pressure cleaning on their reactors on a regular basis, which reduces how much the equipment can be used. ALCOTEX 225 and ALCOTEX 234 scale inhibitors offer a way to address this issue.     1.Industrial Impacts and Scaling Inhibition Needs of Scaling  Scaling happens in polymerization when free radicals or monomers in water stick to solid surfaces like reactor walls or agitators. They then deposit and polymerize more on these surfaces. These solids, especially metals, can have higher temperatures or provide good places for polymerization, which causes local hot spots or uneven reactions. Scaling has several negative effects on S-PVC production, including:  Limited Production Cycle: A certain number of runs must be completed before shutdown for cleaning, limiting continuous production capacity. Product quality fluctuations: Detached scale contaminating the resin can lead to deterioration in product color, thermal stability, and impurity content. Energy consumption and maintenance costs: Increased energy consumption due to the investment in high-pressure cleaning equipment and labor, as well as decreased heat transfer efficiency. The S-PVC industry focuses on making good scale inhibitors because it helps reactors run longer without stopping.   2. ALCOTEX 225: The Main Barrier Against Reactor Wall Sticking ALCOTEX 225 is clearly defined as a scale inhibitor for vinyl chloride suspension polymerization. Its design goal is to eliminate polymer scale buildup on the inner wall of the reactor. 2.1. Physicochemical Properties Property Typical Value Appearance Dark blue aqueous solution Total Solids 5.0–6.0 PH 12.5–13.0 2.2. Mechanism of Action ALCOTEX 225 (POVAL L-10) achieves anti-sticking by forming an extremely thin protective layer on the inner wall of the reactor. This protective layer primarily functions to: Passivate active sites: Cover and passivate active sites on the metal surface that may initiate free radical polymerization. Change surface energy: Adjust the surface energy of the reactor wall to make it unfavorable for the adsorption and wetting of polymers and monomers. Physical Barrier: Establishes a physical barrier to effectively prevent the adhesion and deposition of VCM monomers or primary polymer particles on the reactor wall. This treatment method ensures the reactor wall remains clean during polymerization, which is key to achieving a significant increase in the number of production runs before cleaning.   3. ALCOTEX 234: Synergistic Protector for Internal Components ALCOTEX 234 is not used alone but is designed to work in conjunction with ALCOTEX 225 as a scaling inhibitor. It focuses on areas that are difficult for ALCOTEX 225 to completely cover or are susceptible to mechanical wear. 3.1. Physicochemical Properties Property Typical Value Appearance Dark blue aqueous solution Freezing Point - 1 Specific Gravity 1.1 Total Solids 19.0-21.0 Viscosity @20℃ < 20 PH > 13.0 3.2. Synergistic Application and Targeted Scaling The main function of ALCOTEX 234 is to eliminate scaling on baffles, agitators, or other areas with poor surface quality inside the reactor. Key Protection Areas: Baffles and agitators are areas subjected to high shear forces during polymerization and are also the areas with the most intense heat transfer and monomer/polymer contact. Scaling in these areas is often more stubborn and difficult to inhibit. Synergistic Effect: By applying ALCOTEX 225 to the reactor walls and ALCOTEX 234 to internal components such as agitators and baffles, a comprehensive, high-strength protection is achieved over the entire polymerization contact surface. This combined application strategy is essential for improving overall production efficiency.   4. Application Implementation and Maximizing Industrial Benefits The use of ALCOTEX 225 and 234 imposes specific requirements on the operation of the polymerization process to ensure maximum effectiveness: Thorough Pretreatment: Before first use of the system, all previous polymerization residues in the reactor must be thoroughly removed, and the reactor must be cleaned and dried. Any residual polymer or impurities will affect the adsorption and film formation of the inhibitor. Formulation and Measurement: The concentration and coating amount of the inhibitor need to be precisely optimized based on the reactor geometry, material, and polymerization formulation of the target PVC product. Industrial Benefits: Successful application of the inhibitor system directly results in higher production runs, significantly increased productivity, and improved stability of PVC resin quality.   The ALCOTEX 225 and 234 system is not merely a cleaning agent, but a specialized surface modification and protection system. Together, they constitute a mature and efficient S-PVC scaling management solution, which is a key technological support for modern PVC polymerization plants to achieve high-yield, stable, and high-quality production.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In modern industry, especially in the food, medical, and cosmetic packaging sectors, the requirements for material performance are becoming increasingly stringent. High-barrier materials are crucial for ensuring product quality, extending shelf life, and reducing waste. Ethylene-VinylAlcohol Copolymer is seen as a great green packaging material because it blocks gases, smells, and solvents so well. It also possesses good processability, transparency, mechanical strength, abrasion resistance, and cold resistance.     EVOH is a type of thermoplastic resin made from ethylene and vinyl alcohol. A key feature is the many hydroxyl groups (-OH) in its structure. These groups create strong hydrogen bonds, which limit how well gas molecules, like oxygen, can pass through it. This gives EVOH very good barrier properties. It blocks oxygen much better than common polymers like polyethylene (PE) or polypropylene (PP). In fact, EVOH can be thousands of times better at blocking oxygen.   1.  EVOH EW-3201: Specifications Overview Items Specifications Appearance White transparent particle Melting index (190℃,2160g/10min) 1.5-2.5 Chroma ≤20 Volatile content(%) ≤0.3 Ethylene(mol%) 30.0-34.0 Density (g/cm3) 1.10-1.20   2. In-depth Analysis of Key Physical Properties 2.1 Superior Gas Barrier Performance The core advantage of EW-3201 lies in its ethylene content, ranging from 30.0 to 34.0 mol%. For EVOH (Extracorporeal Membrane Oxide), ethylene content is a crucial parameter: Lower ethylene content: More hydroxyl groups (-OH) on the polymer chain, stronger hydrogen bond network, and better oxygen barrier performance. Higher ethylene content: Better polymer thermal processability (melt index, flexibility), and improved water resistance, but slightly reduced barrier performance. EW-3201's 30.0-34.0 mol% ethylene content provides a good thermal processing window while ensuring extremely high oxygen barrier performance. This method is appropriate for packing food items needing strict preservation (like meats, sauces, and milk products) and medical tools needing high levels of cleanliness, which extends how long they can be stored. 2.2 Ideal Processing Performance The melt index (MI) of EW-3201 is 1.5-2.5 g/10 min, which is a relatively moderate range. Moderate MI: This indicates that its melt viscosity is moderate and its flowability is good, making it suitable for high-speed, complex co-extrusion or lamination processes without excessive degradation during processing. Importance in Co-extrusion: EVOH is typically used in thin layers sandwiched between structural layers such as PE, PP, or PET. The MI value helps EW-3201 match well with typical adhesives and outer layers. This makes for good mixing of multilayer structures and strong sticking between layers. 2.3 High Density and High Transparency EVOH typically has a high density (1.10-1.20 g/cm³), attributed to its highly ordered molecular structure and strong hydrogen bonds. High density is the structural basis for achieving high gas barrier properties. Meanwhile, a colorimetric index below 20 ensures that films or containers made from EW-3201 possess excellent transparency and gloss, crucial performance for packaging that needs to display contents (such as high-end food and cosmetics). 2.4. Environmental Sensitivity  It's important to note that the barrier properties of EVOH are sensitive to environmental humidity. Because the hydroxyl groups on the molecular chain are hydrophilic, when environmental humidity (RH) increases, water molecules enter the hydrogen bond network, weakening hydrogen bonding and leading to increased oxygen permeability.  Application Solution: EW-3201 is commonly paired with thermoplastics like PE, PP, and PET in real-world uses. This is done through co-extrusion or lamination to create a multilayer structure. The EVOH layer is placed between polyolefin layers that have good moisture resistance. This effectively protects the EVOH layer from moisture, allowing it to maintain excellent barrier performance even in high-humidity environments.   3. Main Applications Food Packaging: Used in the production of oxygen barrier films, cling film, aseptic packaging, tubing, and bag-in-bag systems, significantly extending the shelf life of dairy products, jams, meat, seafood, coffee, and tea. Medical Supplies: Used for aseptic packaging of infusion bags and medical devices, preventing product oxidation and microbial contamination. Industry and Agriculture: Used as an oxygen barrier layer for underfloor heating pipes to prevent pipe corrosion; or for solvent-resistant containers for solvents and chemicals. Cosmetic Packaging: Used in the production of multi-layer cosmetic tubing and containers, effectively preventing the oxidation or volatilization of fragrances, vitamins, and other active ingredients.   As the packaging industry needs thinner, more efficient, and greener materials, good ethylene vinyl alcohol (EVOH) products such as EW-3201 (EVASIN EV-4405F) will keep being very important and will push forward barrier packaging tech improvements around the world. Choosing EW-3201 means choosing a high-performance, highly reliable, and sustainable packaging future.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In the polyvinyl chloride (PVC) suspension polymerization process, selecting the right suspending agent is crucial for controlling polymer particle morphology, particle size distribution, and porosity. Both ALCOTEX B72 and its modified version, ALCOTEX B72-LF, are high-performance polyvinyl alcohol (PVA) specifically developed as primary suspending agents for VCL suspension polymerization. B72 and B72-LF share similar applications and properties, but B72-LF is designed to solve a frequent problem in polymerization. Here, we will compare the technical specs, benefits, and proper uses of both B72 and B72-LF. This information should guide PVC manufacturers to select the right product for their specific needs.      1. Comparison of Core Technical Parameters Property ALCOTEX B72  ALCOTEX B72-LF Appearance Dark yellow granulesanules Dark yellow granulesanules Degree of Hydrolysis 72.0-74.0 72.0-74.0 Viscosity @ 20℃, 4% solution 5.0-5.8 5.0-5.8 Ash Content 0.5 max 0.5 max Total Solids > 95.0 > 95.0   2. Differentiation of Application Advantages—Process Optimization vs. Product Quality The advantages of ALCOTEX B72 primarily focus on reducing operating costs and improving PVC polymer quality. The ALCOTEX B72-LF builds upon this foundation with enhanced process stability.   2.1 Shared Quality Advantages of the B72/B72-LF Reactor Output and Cost: Low fouling in polymerization reactors reduces downtime for cleaning. Required particle size control can be achieved at lower concentrations. Particle Morphology and Flowability: The resulting PVC particles tend to be more spherical, helping to minimize bulk density reduction at high porosity, resulting in optimal flow properties. Porosity and Degassing: The produced PVC particles exhibit good porosity, facilitating the removal of free monomers. Defect Control: Narrow particle size distribution and low oversized reject rate. Low "fisheye" count reduces reject levels in critical applications. Plasticizer Absorption: Adjustable plasticizer absorption properties provide fast drying times. Operational Characteristics: Low dust generation.   2.2 B72-LF's Unique Advantage: Anti-Foaming Properties Foaming is a common process obstacle in suspension polymerization, potentially leading to reduced reactor charge, increased reactor wall fouling, and even impacting polymerization stability. ALCOTEX B72-LF was specifically developed to address this foaming issue. It offers the added benefit of reducing foaming during S-PVC polymerization. Process Benefits: By minimizing foaming during suspension polymerization, B72-LF can help manufacturers maintain or improve throughput and production efficiency. Comparative Conclusion: B72 focuses on providing comprehensive, high-quality PVC product specifications and excellent operating characteristics. B72-LF builds on this strength, offering manufacturers struggling with foaming a process solution without compromising PVC quality.   3. Similarities in Storage and Logistics Both products demonstrate high consistency in storage and supply, facilitating standardized supply chain management and operational procedures: Storage Conditions: Both products should be stored in a dry area, and moisture ingress must be avoided to maintain product quality. Shelf Life: As supplied, both products should maintain suitability for 24 months from the date of production. Testing Recommendations: Both products recommend testing before use for materials stored for 12 months or longer. Aqueous Solutions: Aqueous solutions of both products are susceptible to mold and bacterial attack if stored at elevated temperatures for extended periods. Packaging: Both products are supplied in 25 kg plastic bags and 1000 kg bulk bags.   4. Application Selection Recommendations ALCOTEX B72: Standard Process: Stable process operation with minimal foaming issues. The primary goal is to achieve high-quality PVC pellets and low operating costs. Cost-Effectiveness and Quality Assurance: Achieve excellent particle size, porosity, flowability, and low defectivity with minimal investment. ALCOTEX B72-LF Challenging Process: Significant foaming tendency during polymerization, or manufacturers seeking to maximize reactor load and throughput. Process Optimization and Efficiency Improvement: Maintains all the quality advantages of B72 while providing strong anti-foaming properties, ensuring stable and efficient production processes.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

The core of polyvinyl alcohol (PVA) performance lies in its degree of hydrolysis. The 88 Series PVA, which is partially hydrolyzed (usually around 87.0 to 89.0 mol%), differs from the fully hydrolyzed 99 Series in that it provides better flexibility, interfacial activity, and water solubility that can be adjusted. When PVA is partially hydrolyzed, about 11% to 13% of vinyl acetate groups (-OAc) are kept in the molecular chain. Because of these hydrophobic groups, the 88 Series PVA acts as an amphiphilic substance with high interfacial activity, unlike the 99 Series. Because of this, it works well as a protective colloid in emulsion polymerization and as a flexible base for strong adhesives and coatings with specific functions.     1. Molecular Structure Determines Function: Amphiphilicity and Protective Colloid Mechanism 1.1  Amphiphilicity Due to Hydrophobic-Hydrophilic Balance Partially hydrolyzed 88 series PVA molecular chains possess two functional groups with vastly different polarities: Hydrophilic groups: A large number of hydroxyl groups (-OH). Hydrophobic groups: A small number of evenly distributed vinyl acetate groups (-OAc). This structure makes PVA a highly effective high-molecular-weight surfactant or protective colloid. When dissolved in water, the molecular chains adsorb at the water-oil (monomer) interface, with the hydrophobic groups tending to embed into the oil phase, while the hydrophilic groups extend toward the water phase. This unique arrangement forms a stable, high-molecular-weight physical barrier (i.e., a protective steric barrier) around the oil phase particles, effectively preventing aggregation of emulsion particles during polymerization, storage, or mechanical shear, and is the core mechanism for ensuring emulsion stability. 1.2 Reduced Crystallinity and Improved Water Solubility Unlike the highly regular structure of the 99 series, the irregular distribution of vinyl acetate groups on the molecular chain disrupts the regular packing of PVA molecules, resulting in: Reduced crystallinity: The proportion of crystalline regions decreases, weakening the hydrogen bond network. Improved cold-water solubility: Lower crystallinity allows water molecules to more easily penetrate and disrupt the amorphous region structure. Therefore, 88 series PVA can dissolve quickly or even completely at lower temperatures (typically 40°C to 60°C), greatly simplifying dissolution operations during formulation and production.   2. Effect of Degree of Polymerization on Rheological Properties and Stability Given a consistent level of partial hydrolysis, the key differences between different PVA grades are mainly in their average degree of polymerization (DP) or molecular weight (MW). The DP has a direct impact on the viscosity of the PVA solution, the thickness of the steric barrier layer, and how the emulsion ultimately performs. The refined positioning of ElephChem's 88 series grades: ElephChem PVA Average degree of polymerization Average molecular weight Core application positioning 2688 / 2488 2400~2650 118000~130000 High molecular weight: Provides the strongest steric protection and is used in emulsion polymerizations requiring the highest stability (such as high-performance VAE emulsions). 2088 / 1788 1700~2100 84000~104000 General purpose: Balances viscosity and protection for general-purpose PVAc and VAE emulsions and adhesives. 1792 1700~1800 54000~60000 Medium-low molecular weight: Suitable for specialty water-soluble fibers and viscosity-sensitive coating systems. 0588 / 0488 420~650 21000~32000 Ultra-low molecular weight: Minimal effect on solution viscosity, suitable for inks, inkjet coatings, or as a co-stabilizer in emulsions. High degree of polymerization (Polyvinyl Alcohol 2688 / Polyvinyl Alcohol 2488): Long molecular chains provide a stronger steric hindrance. In emulsion polymerization, long chains help distribute and stabilize monomer droplets and polymer particles, which is needed for high-solids, high-viscosity emulsions. Ultra-low degree of polymerization (Polyvinyl Alcohol 0488 / Polyvinyl Alcohol 0588): These stabilizers function similarly to small-molecule emulsifiers, but provide improved polymer adhesion. Their low viscosity allows them to be used in high-solids coatings and slurry systems without affecting the rheological properties of the final product.   3. Analysis of Key Industrial Applications of Partially Hydrolyzed 88 Series PVA The interfacial activity and controllable water solubility of the 88 series PVAs give them core competitiveness in the fine chemicals, adhesives, and specialty materials sectors: 3.1 Emulsion Polymerization Industry: Stabilizers and Protective Colloids This is the core and irreplaceable application of the 88 series PVAs. It is widely used in the polymerization of monomers such as vinyl acetate (VAc), acrylates, and styrene-acrylates, and is a key additive in the manufacture of PVAc, VAE, and acrylate emulsions. Mechanism: 88 Series PVA acts as a protective colloid, not only stabilizing the emulsion during the initial polymerization phase but, more importantly, determining the freeze-thaw resistance, mechanical shear stability, and rewettability of the final emulsion. Applications: Architectural coating emulsions (such as interior wall latex paint), wood adhesives (white latex), textile nonwoven adhesives, carpet adhesives, etc. 3.2 Water-Solubility and Functional Films/Fibers The low crystallinity of partially hydrolyzed PVA makes it easier to dissolve quickly in cold water, making it a preferred environmentally friendly packaging material. Water-Soluble Packaging Film: Used for quantitative packaging of products such as pesticides, dyes, detergents, and laundry detergent beads. Upon application of water, the film quickly dissolves, releasing the contents, providing both convenience and environmental friendliness. Water-Soluble Fiber: Used in the textile industry as temporary support yarn or "sacrificial" yarn. After the fabric is finished, the PVA fibers dissolve in warm water, leaving behind a fabric with a special openwork or structural effect. 3.3 Adhesive and Coating Systems Adhesives: Due to the retention of hydrophobic groups in the molecular chain, 88-series PVA has better affinity and adhesion to certain hydrophobic surfaces and organic materials than 99-series PVA. It is widely used in specialty paper adhesives and rewettable adhesives (such as postage stamp adhesives). Specialty Coatings: Ultra-low molecular weight grades (such as 0488) can be used as ink-receiving coating additives for inkjet printing paper, providing excellent pigment binding and fast drying properties without significantly increasing coating viscosity. 3.4 Other Fine Chemical Applications Suspension Polymerization Dispersant: Used in the suspension polymerization of PVC resins, it helps control the size, porosity, and density of PVC particles, which is crucial to the processing properties of PVC resins. Ceramic Binder: Used as a temporary binder for bonding ceramics before molding and sintering. After sintering, it can be completely burned and vaporized, leaving no residue.   4. Conclusion: Continuous Innovation in Partially Hydrolyzed 88 Series PVA ElephChem partially hydrolyzed 88 Series PVA takes full advantage of both hydrophilic and hydrophobic elements in its molecular structure. This allows for careful control during emulsion polymerization and affects how well it sticks and dissolves in water. If the 99 Series is the "rebar" of structural materials, then the 88 Series is the "stabilizer" and "flexibility controller" of fine chemical systems. Partially hydrolyzed 88 Series PVA is still critical to the growth of modern fine chemicals and sustainable materials. This is due to the continued expansion of markets, like those for green water-based coatings, good emulsions, and biodegradable packaging, along with PVA's special interfacial chemistry and grade system.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com