How To Make PVC Latex Work For You?

Manufacturer: We're in the process of evaluating various synthetic latices (latexes) to see if they could complement our products currently made from natural rubber latex either on their own or as a blend with natural rubber latex. We've been having good results except for PVC latex which behaves quite differently from other latices. We could not get it to form a film. Could you help? How do we compound a PVC latex?

John Woon (Senior Latex and Rubber Consultant):  PVC latex or emulsion was developed as an alternative to PVC plastisol (PVC dispersed in plasticizers) because the latex version offers comparatively lower viscosity with greater versatility in compounding. Unlike elastomeric polymers (i.e. soft rubbers), PVC which is rigid does not readily form a film on drying without heat.

Temperatures up to 160ºC is required to coalesce and fuse the PVC particles together. However, this temperature could be reduced by adding a plasticizer. The PVC latex manufacturer could also modify the polymer with a second monomer during polymerization to reduce the fusing temperature to as low as the room temperature. You need to get the right grade for your purpose.

PVC latex can be compounded with colloidal stabilizers, wetting agent, thickeners, anti-foaming agents, pH modifiers, heat stabilizers (as PVC tends to discolour on heating), plasticizer, fillers, pigments, anti-blocking agent (e.g. waxes) etc.

Nitrile latex could be added to PVC latex with the former acting as the plasticizer for the latter.