Modified PVA 552

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  

Membrane materials technology plays a key role in environmental protection, energy, biomedicine, and other fields. Polyvinyl alcohol (PVA) has become a key target of membrane material research due to its excellent water solubility, film-forming properties, and biocompatibility. However, due to the high concentration of hydroxyl groups in its molecular chains, PVA easily swells or dissolves in high-humidity environments, affecting its stability in complex applications. To overcome these limitations, research on Modified Polyvinyl Alcohol has intensified in recent years. Through chemical cross-linking, blending, and inorganic filler incorporation, the water resistance, mechanical properties, and chemical stability of Polyvinyl alcohol film (PVA film) have been significantly improved. Modified PVA membranes have found widespread application in water treatment, fuel cells, gas separation, and other fields. The rise of green and environmentally friendly modification technologies has given PVA membranes greater potential for biodegradable and environmentally friendly applications. By optimizing production processes and expanding functional modification strategies, PVA membranes will play a more significant role in the field of high-performance membrane materials.     1. Polyvinyl Alcohol Modification Methods 1.1 Chemical Crosslinking Polyvinyl alcohol (PVA) is a highly polar polymer. Due to the large number of hydroxyl groups on its backbone, it easily forms hydrogen bonds with water molecules, causing it to swell or even dissolve in humid environments. This significantly limits its stability in certain applications. Chemical crosslinking is an effective method. By introducing crosslinks between PVA molecular chains, a stable three-dimensional network is formed, thereby reducing its water solubility and improving its water resistance and thermal stability. Crosslinking typically involves introducing covalent bonds between PVA molecules, making the polymer chains less dispersible in water. Common crosslinking agents include aldehydes (such as glutaraldehyde), epoxides (such as epichlorohydrin), and polyacids (such as citric acid and maleic anhydride). Different crosslinking agents affect the crosslinking pattern and the properties of the modified polymer. For instance, when glutaraldehyde meets PVA's hydroxyl groups in an acidic environment, they create a solid crosslinked structure. Also, maleic anhydride can link PVA sections by esterification, which really helps PVA resist water. Because these cross-linked PVA films have stronger links between molecules, they can handle more heat, as seen by their higher glass transition temperature (Tg) and thermal decomposition temperature (Td).   1.2 Blending Modification Blending modification is another important method for improving PVA film performance. By blending with other polymers, PVA's mechanical properties, water resistance, and chemical stability can be optimized. Due to PVA's inherently hydrophilic nature, direct blending with hydrophobic polymers may present compatibility issues. Therefore, it is important to select appropriate blending materials and optimize the blending process. For example, when blended with polyvinyl butyral (PVB), PVB's hydrophobicity enables PVA films to maintain good morphological stability even in high humidity environments. Furthermore, PVB's high glass transition temperature improves the heat resistance of the blended films. Blending with polyvinylidene fluoride (PVDF) significantly enhances the hydrophobicity of PVA films. Furthermore, PVDF's excellent chemical resistance allows the blended films to remain stable even in complex chemical environments. PVA can also be blended with polyethersulfone (PES) and polyacrylonitrile (PAN) to enhance the membrane's selective permeability, making it more widely applicable in gas separation and water purification membranes.   2. Application of PVA Modified Membranes in High-Performance Membrane Materials 2.1 Water Treatment Membranes The development of water treatment membrane technology is crucial for addressing water resource shortages and improving water quality and safety. PVA membranes work really well as films and get along with living tissue, so they could be used in all sorts of membrane separation stuff like ultrafiltration, nanofiltration, and reverse osmosis. But, because PVA loves water and dissolves in it, it can break down over time. This makes the membrane weaker and not last as long. That's why changing up PVA membranes has become a big focus in water treatment research. Chemical crosslinking is a key technology for improving the water resistance of PVA membranes. Crosslinking agents (such as glutaraldehyde and maleic anhydride) form stable chemical bonds between PVA molecular chains, maintaining the membrane's stable morphology in aqueous environments and extending its service life. In addition, the introduction of inorganic fillers is also an important means of improving the hydrolysis resistance and mechanical strength of PVA membranes. Adding nano-silica (SiO₂) and nano-alumina (Al₂O₃) can create a strong mix in the membrane material. This makes the membrane better at resisting breakdown from water and boosts its strength. So, it keeps working well even with high pressure. Also, mixing PVA with other polymers like polyethersulfone (PES) and polyvinylidene fluoride (PVDF) makes the membrane more water-resistant and less prone to fouling. This means it lasts longer and maintains its flow rate, even with dirt buildup.   2.2 Proton Exchange Membranes for Fuel Cells Fuel cells are clean and efficient energy conversion devices, and proton exchange membranes, as their core component, determine their performance and lifespan. PVA, due to its excellent film-forming properties and processability, is a promising candidate for proton exchange membranes. However, its low proton conductivity in its raw state makes it difficult to meet the high-efficiency requirements of fuel cells, necessitating modification to increase proton conductivity. Sulfonation modification is one of the key methods for improving the proton conductivity of PVA membranes. To boost how well membranes absorb water and help protons move better, we add sulfonic acid to the PVA chain. This makes continuous water channels. Mixing it up can also do the trick. If you mix PVA with SPS and SPEEK, they form a network that helps exchange protons and makes the membrane stronger. But, using PVA membranes in DMFCs has its problems. Methanol can leak through, wasting fuel and making things worse. To fix this, scientists have added things such as sulfonated silica and zirconia nanoparticles to PVA membranes. They also use layers to block methanol from passing through the membrane and reduce leakage.   3. Development Trends and Challenges 3.1 Development of Green and Environmentally Friendly Modification Technologies With increasingly stringent environmental regulations and the growing adoption of sustainable development concepts, green and environmentally friendly modification technologies for PVA films have become a key research focus. Research on biodegradable PVA films has made significant progress in recent years. By blending with natural polymers (such as chitosan, starch, and cellulose) or introducing biodegradable nanofillers (such as hydroxyapatite and bio-based nanocellulose), the biodegradability of PVA films can be significantly improved, making them more easily decomposed in the natural environment and reducing pollution to the ecosystem. Furthermore, to reduce the environmental and human impact of toxic chemicals used in traditional cross-linking modification processes, researchers have begun developing non-toxic cross-linking agents and more environmentally friendly modification processes. These include chemical cross-linking using natural cross-linkers such as citric acid and chitosan, and physical modification methods such as ultraviolet light and plasma treatment, achieving pollution-free cross-linking. These green modification technologies not only enhance the environmental friendliness of PVA films but also enhance their application value in food packaging, biomedicine, and other fields, making them a key direction for the future development of polymer membrane materials.   3.2 Challenges and Solutions for Industrial Application Although modified PVA films hold broad application prospects in the field of high-performance membrane materials, they still face numerous challenges in their industrialization. High production costs are a major bottleneck, particularly for PVA films involving nanofillers or special modifications. Expensive raw materials and complex preparation processes limit large-scale production. Process optimization still requires improvement. Currently, some modification methods suffer from high energy consumption and long production cycles, hindering the economic viability and feasibility of industrial production. To address these issues, future efforts will focus on developing low-cost, efficient preparation processes, such as adopting environmentally friendly aqueous synthesis techniques to improve production efficiency, while optimizing the blending system to enhance the performance stability of PVA films. Furthermore, future development directions for high-performance PVA films will focus on improving durability, reducing production energy consumption, and expanding intelligent functionality. For example, developing intelligent PVA films that can respond to external stimuli (such as temperature and pH changes) to meet a wider range of industrial and biomedical needs.   4. Conclusion Polyvinyl alcohol (PVA), as a high-performance polymer, holds broad application prospects in the membrane material field. PVA films can be made stronger and more resistant to the elements by using methods like chemical cross-linking, co-modification, and adding inorganic fillers. This makes them suitable for things like water treatment and fuel cells. Also, new green modification tech has made PVA films break down easier and be less toxic. This means they could be big in environmental protection and medical uses. In the future, industrial applications will still face challenges in production costs and process optimization. Further improvements in the economic efficiency and feasibility of modification technologies are needed to promote the widespread application of PVA films in the field of high-performance membrane materials and provide higher-quality membrane material solutions for sustainable development.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Polyvinyl alcohol (PVA), a water-soluble synthetic polymer, is widely used in textiles, papermaking, construction, coatings, and other fields due to its excellent film-forming, adhesive, emulsifiable, and biodegradable properties. However, standard PVA may have performance limitations (such as water resistance, flexibility, and redispersibility) in certain specific applications. To overcome these challenges, scientists have developed a series of modified PVAs by introducing various functional groups or modifying the polymerization process. Compared to standard PVA, these modified PVA exhibit significant performance advantages in many aspects. 1. Better Water Resistance and Stickiness The abundance of hydroxyl groups (-OH) in the standard PVA molecular chain makes it extremely hydrophilic. However, this also means that it is prone to swelling and even dissolution in hot and humid environments, resulting in reduced bond strength. Modified PVA, by introducing hydrophobic functional groups (such as acetyl and siloxane groups) or through crosslinking reactions (such as boric acid crosslinking and aldehyde crosslinking), can effectively reduce its swelling in water, significantly improving its water resistance. For example, in dry-mix mortars for construction, modified PVA used in tile adhesives can form a more stable and moisture-resistant bond, ensuring that tiles will not fall off due to moisture erosion during long-term use. These modifications also enhance the cohesion between PVA molecular chains, strengthening its adhesion to various substrates (such as cellulose and inorganic powders), thereby imparting higher cohesive and adhesive strength to the final product.   2. Optimized Redispersibility and Compatibility Certain applications, such as the production of redispersible polymer powders (RDPs), place stringent requirements on the redispersibility of the polymer. Standard PVA, used as a protective colloid, can easily cause emulsion particles to agglomerate during the spray drying process, affecting the final properties of the RDP. Modified PVA, such as partially alcoholyzed PVA with a high degree of polymerization, produced through specialized polymerization processes, or PVA containing specific hydrophilic/hydrophobic segments, can more effectively stabilize emulsion systems. The protective layer they form after drying allows for rapid and uniform redispersion upon re-addition of water, even after prolonged storage, restoring the original emulsion state. This optimized redispersibility is crucial for ensuring the workability of products such as dry-mix mortar and putty powder. Furthermore, the introduction of specific functional groups into modified PVA can improve its compatibility with certain additives (such as cellulose ethers and starch ethers), reducing system interactions and flocculation, thereby achieving synergistic effects within the formulation and achieving more stable and efficient product performance.   3. Broader Application Potential and Customizable Performance While standard PVA has relatively fixed properties, the customizability of modified PVA opens up a wider range of applications. Through precise chemical modification, PVA can be endowed with a variety of customized properties to meet the stringent requirements of specific industries. For example, silane-modified PVA can significantly improve its adhesion and alkali resistance in cementitious materials; vinyl acetate-modified PVA offers enhanced flexibility and lower film-forming temperatures; and certain bio-modified PVAs may find new applications in the biomedical field. This ability to be "functionalized" to meet specific needs elevates modified PVA from simply a basic raw material to a high-performance additive capable of solving specific technical challenges.   In summary, while standard PVA remains indispensable in many fields, modified PVA, with its significant advantages in water resistance, adhesive strength, redispersibility, and customizability, has achieved a leap from "general purpose" to "specialized," and from "passive" to "intelligent." Whether pushing the performance limits of traditional applications or pioneering cutting-edge technologies such as biomedicine, environmental engineering, and smart materials, modified PVA (such as PVOH 552) demonstrates immense potential and is undoubtedly a key direction for the future development of polymer materials.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

The shift toward green packaging in the food industry is imperative.   Flexible packaging is becoming really important in the food industry. This product is safe for the environment and doesn’t contain any toxic materials. Unlike PVDC, it leaves no solvent residues and doesn’t release harmful gases when burned, so it’s a better choice for sustainability.   Under the same conditions, its oxygen barrier performance is 50 times higher than that of PVDC, effectively addressing many challenges in the packaging industry.   Polyvinyl alcohol (PVC Grade) coated film is a novel, eco-friendly, high-barrier packaging material that can replace PVDC in general food packaging applications while also meeting stricter environmental requirements in other packaging fields.   Differences Between PVOH High-Barrier Coated Film and K-Film     1. Structure: Self-adhesive, no primer required.        2. Performance:   Eco-friendly & Cost-Efficient: Low coating weight, no organic solvents used, no solvent emissions or residues. Superior Oxygen Barrier: Thinner coating, lower haze, higher transparency, and exceptional oxygen barrier performance. Higher Yield: It offers a bigger packaging area, about 15% more per roll than K-film of the same weight and width, which means you can pack more products. . Recyclability: The PVOH-coated film is both degradable and recyclable.   In summary, this eco-friendly PVOH (PVOH 552 & Aclotex B72) -coated film could fill a gap in the market. It can replace traditional PVDC in food packaging and meet the needs of industries focused on environmental issues. Plus, it effectively handles current sustainability challenges and provides good oxygen barriers for flexible food packaging.It's likely to take the place of a lot of metallized film packaging out there.   This new product is designed to tackle the ongoing issue of plastic waste in food packaging and support the move towards eco-friendly materials in China.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com