Question: We manufacture a polyvinyl acetate emulsion sealant that is heavily filled with calcium carbonate and would like to improve its flexibility. Can you recommend a suitable plasticizer?
Answer: I would suggest two possible approaches to the flexibility issue. First, you could try one of the commonly used plasticizers for PVA emulsions - dibutyl phthalate and di-isobutyl phthalate are typical examples. Another approach would be to use an ethylene-vinyl acetate (EVA) or a flexible acrylic emulsion. The ethylene groups in an EVA polymer act as internal plasticizers and often allow formulation without any added plasticizers. Your final decision will be based on a combination of cost and performance. If performance is the only issue, a suitably chosen flexible acrylic will have the highest performance, but will also have the highest cost.