ALCOTEX 7206

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

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

Gloves are the most commonly used protective tools in the laboratory besides goggles. There are many types of gloves, and different gloves have different uses.     1. Natural rubber (latex) Latex gloves, made from natural rubber, typically lack a lining and are available in both clean and sterile versions. These gloves can provide effective protection against alkalis, alcohols, and a variety of chemical dilution aqueous solutions, and can better prevent corrosion from aldehydes and ketones.   2. Polyvinyl chloride (PVC) gloves The gloves do not contain allergens, are powder-free, have low dust generation, low ion content, strong chemical corrosion resistance, can protect almost all chemical hazardous substances, and also have anti-static properties. Thickened and treated surfaces (such as fleece surfaces) can also prevent general mechanical wear, and thickened types can also prevent cold, with an operating temperature of -4℃ to 66℃. Can be used in a dust-free environment. PVC gloves grading standards: Grade A products, no holes on the surface of the gloves (PVC gloves with powder), uniform powder, no obvious powder, transparent milky white color, no obvious ink spots, no impurities, and the size and physical properties of each part meet customer requirements. Grade B products, slight stains, 3 small black spots (1mm≤diameter≤2mm), or a large number of small black spots (diameter≤1mm) (diameter>5), deformation, impurities (diameter≤1mm), slightly yellow color, serious nail marks, cracks, and the size and physical properties of each part do not meet the requirements.   3. PE gloves PE gloves are disposable gloves made of polyethylene. These gloves are waterproof, oil-proof, anti-bacterial, and resistant to acids and bases. Note: PE gloves are safe to use with food and are non-toxic. It is better to keep PVC gloves away from food, especially if it's hot.     4. Nitrile rubber gloves Nitrile rubber gloves are usually divided into disposable gloves, medium-duty unlined gloves and light-duty lined gloves. These gloves can prevent erosion by grease (including animal fat), xylene, polyethylene and aliphatic solvents; they can also prevent most pesticide formulations and are often used in the use of biological components and other chemicals. Nitrile rubber gloves do not contain protein, amino compounds and other harmful substances, and rarely cause allergies. They are silicone-free and have certain antistatic properties, which are suitable for the production needs of the electronics industry. They have low surface chemical residues, low ion content and small particle content, and are suitable for strict clean room environments.   5. Neoprene gloves Similar to the comfort of natural rubber, neoprene gloves are resistant to light, aging, flexing, acid and alkali, ozone, combustion, heat and oil.   6. Butyl rubber gloves Butyl rubber is only used as a material for medium-sized unlined gloves and can be used for operations in glove boxes, anaerobic boxes, incubators, and operating boxes; it has super durability against fluoric acid, aqua regia, nitric acid, strong acids, strong alkalis, toluene, alcohol, etc., and is a special rubber synthetic resistant liquid gloves.   7. Polyvinyl alcohol (PVA) gloves Polyvinyl alcohol (PVA) can be used as a material for medium-sized lined gloves, so this type of gloves can provide a high level of protection and corrosion resistance against a variety of organic chemicals, such as aliphatic, aromatic hydrocarbons, chlorinated solvents, fluorocarbons and most ketones (except acetone), esters and ethers.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com