Abstract: A simple and practical method for making post-chlorinated polymers based upon vinyl chloride is provided based upon conducting the chlorination reaction on a granular polymer suspended in aqueous hydrochloric acid in the presence of a stoichiometric excess of liquid chlorine and in the absence of any significant amount or organic solvent/swelling agent. Use of photo-radiation techniques is also avoided since the reaction is activated by means of a minor fraction of a percent based upon weight of said polymer of an organic peroxy compound which decomposes to form free radicals at the temperatures involved in the reaction.

Abstract: In the process disclosed herein, a latex comprising a diene rubber pregrafted with styrene/acrylonitrile type monomer mixtures, for example, about 5 to 50% by weight styrene/acrylonitrile emulsion-grafted thereon, is added to an aqueous solution of suspending agent. Additional styrene/acrylonitrile type monomers are then added to the dispersion and polymerized onto the suspended rubbery particles with peroxide initiator to produce ABS type polymers containing from about 3 to less than about 30 percent by weight diene rubber.