Emulsion PVC E-PVC: Properties and Applications

Emulsion PVC (E-PVC) - Complete Overview

What is Emulsion PVC?

Emulsion Polyvinyl Chloride (E-PVC) is a fine-particle powder polymer produced by emulsion polymerization of vinyl chloride in the presence of water-soluble initiators and surfactants (soaps or emulsifiers). Unlike suspension PVC (S-PVC), which has a porous particle structure of 50-250 µm, emulsion PVC consists of tiny smooth spherical primary particles with a diameter of 0.1-2 µm that cluster into aggregates with a mean particle size of 40-50 µm.

E-PVC accounts for less than 5% of the global PVC market, but occupies a unique niche due to its ability to form stable pastes (plastisols) when mixed with plasticizers. This feature makes it an indispensable material for the production of a wide range of coatings, artificial leather, gloves, and other products.

How is E-PVC Produced?

E-PVC production is carried out by three main technological processes: batch emulsion polymerization, continuous emulsion polymerization, and microsuspension polymerization.

Batch emulsion polymerization - the classic method where vinyl chloride is dispersed in water using emulsifiers (e.g., alkyl sulfonates or alkyl sulfates). The monomer is trapped inside soap micelles, and polymerization is initiated by water-soluble initiators such as persulfates. The process requires approximately 1% emulsifier. The resulting primary particles have a size of about 0.2 µm.

Continuous emulsion polymerization - requires more emulsifier (2.5-3.0%). The resulting E-PVC has a broader particle size range and provides lower plastisol viscosity.

Microsuspension polymerization - uses less emulsifier compared to batch and continuous processes and allows achieving significantly lower plastisol viscosity.

After polymerization, the resulting latex is spray-dried to produce commercial paste resin powder. When mixed with plasticizer, the aggregates break down into primary particles that are wetted and surrounded by plasticizer, forming a stable, flowable paste.

Key Physical and Chemical Properties

Emulsion PVC has a number of unique properties that determine its application.

Particle size - primary particles 0.1-2 µm, aggregates 40-50 µm (range 0.1-100 µm). Suspension PVC particles are significantly larger - 50-250 µm. Paste-forming PVC grades obtained by emulsion or microsuspension polymerization have a particle diameter of 0.3-2.5 µm.

K-value - characterizes the molecular weight of the polymer. Commercial E-PVC grades range from K-60 to K-80. Lower K-values give lower melt viscosity and better flow, higher K-values provide greater tensile strength and heat resistance.

Bulk density - may vary by grade, e.g., 0.320 g/cm³ for SABIC PVC 701E or 0.560 g/cm³ for Vinnolit® E 2169.

Thermal properties - E-PVC is processed at relatively low temperatures, which is advantageous for molding and coating, while retaining good thermal stability in final applications. Plastisols are fused (gelled) by heating to 160-200 °C.

Chemical resistance - emulsion PVC offers good chemical resistance to many acids, bases, and other chemical agents.

Antistatic properties - the remaining amount of emulsifiers acts as an external lubricant and also gives E-PVC good antistatic properties in final products.

Processing Features: Plastisols

The main feature of E-PVC is its ability to form plastisols (plastic-viscous polymer pastes) when mixed with plasticizers. Plastisols are concentrated dispersions of solid powdered polymer in plasticizers that have high fluidity at normal temperature.

Key characteristics of plastisols:

• Low initial viscosity - ensures ease of application

• Storage stability - ability to maintain fluidity for a long time (up to several months)

• Controlled rheology - ability to control viscosity for specific application methods

• Low gelation temperature - for some grades

For plastisol preparation, E-PVC is mixed with plasticizers (30-150% by weight of polymer), as well as fillers, colorants, thermal stabilizers, and other ingredients. The preparation process is carried out at temperatures not exceeding 35 °C with mandatory vacuuming to remove air and volatiles.

Plastisol processing methods include: dipping, casting into molds, application to substrates by spreading, spraying, extrusion followed by gelation at 120-200 °C.

Applications of E-PVC

Thanks to its ability to form stable plastisols, emulsion PVC has found wide application in various industries.

Artificial leather and textile coatings - one of the key applications. E-PVC is used for artificial leather production for clothing, accessories, footwear, furniture. Coatings are applied to fabrics by direct or transfer coating, knife-over-roll, reverse roll coating.

Flooring - vinyl linoleum, tiles, carpet backing. E-PVC plastisols provide wear resistance and durability.

Wall coverings and wallpaper - hot embossing of wallpaper, washable wallpaper production.

Automotive protection - anti-gravel underbody coatings, sealants. E-PVC grades such as Vinnolit® E 70 CQ are specifically designed for automotive underbody coatings.

Gloves - medical, industrial, and household gloves.

Toys - inflatable toys, balls, play products.

Industrial products - conveyor belts, sealants, sealing compounds.

Medical devices - medical devices and products.

Cable insulation - insulation and sheathing of cables.

Comparison of E-PVC and S-PVC

Major E-PVC Producing Countries

The global emulsion PVC market is represented by a limited number of major producers.

Major manufacturers:

• Westlake Vinnolit (Germany) - one of the world leaders, Vinnolit® E series

• SABIC (Saudi Arabia) - SABIC® PVC 701E, 703E grades

• INEOS (UK)

• Synthos S.A. (Poland) - Synthos E660, E680 grades

• LG Chem (South Korea)

• Shin-Etsu Chemical (Japan)

• ChemChina (China)

• Karpatnaftokhim (Ukraine) - produces emulsion PVC

Production regions:

• Europe: Germany (Westlake Vinnolit), Poland (Synthos), UK (INEOS)

• Asia-Pacific: China, Japan, South Korea

• Middle East: Saudi Arabia (SABIC)

In Russia, emulsion PVC is not produced on an industrial scale; market demand is met by imports from Europe and China.

Conclusion

Emulsion polyvinyl chloride is a unique type of PVC occupying a special niche in the global polymer market (less than 5% of total PVC volume). Thanks to its ultra-fine particle size and ability to form stable plastisols, E-PVC is an indispensable material for the production of artificial leather, floor and wall coverings, automotive protective coatings, gloves, and many other products. Unlike suspension PVC, which is mainly used for rigid structural products, emulsion PVC is focused on the production of elastic coatings and paste compositions. Understanding the specifics of production, properties, and applications of E-PVC helps market participants make informed purchasing decisions for this specialized raw material.