VAE polymers are available as dispersions, powder or resin. Especially dry VAE powders can be blended with casein powder. Dispersions can be mixed with fluid (water blend) casein.
Casein can be considered as biopolymers. Some VAE polymers have been proven not to affect compostability of biopolymers negative. As seen in this article.
Range of VAE water solluble powders
VAE can improved the adhesion and water resistancy of case adhesives. There are several VAE polymers available.