Abstract: Polymer powders comprising aggregated polymer particles, said powders having a low content of fines and being suitable as processing aids in the manufacture of polyvinyl chloride, are made by spray drying an aqueous dispersion (latex) of two emulsion polymers, one of which has a dynamic glass transition temperature above 90.degree. C. and the other of which has a dynamic glass transition below 105.degree. C., the latter being at least 10 K. degrees below the former.

Abstract: What are disclosed are concentrated emulsions of an olefin copolymer in a liquid carrier medium which does not dissolve the copolymer and, as an emulsifier, a graft or block copolymer of the formulaA--Y,wherein A represents a sequence or segment of an olefin copolymer, of hydrogenated polyisoprene, or of an hydrogenated butadiene/isoprene copolymer, and Y represents a sequence or segment, formed by the polymerization of vinyl monomers which essentially are not of the acrylate or methacrylate type, which is soluble in the carrier medium, as well as methods for making the same.