Sulfonated polymer composition

Claim 1

An improved process for the preparation of a plasticized composition of a sulfonated polymer from a neutralized sulfonated polymer having about 0.1 to about 10.0 mole percent sulfonate groups, at least 90% of which being neutralized with a neutralizing agent selected from the group consisting of metallic derivatives of organic acids, metallic alkanoates, metallic hydroxides, and amine derivatives and mixtures thereof, wherein the improvement comprises: (a) adding at ambient temperature about 1 to about 50 parts per hundred by weight of a reactive plasticizer to 100 parts of said neutralized sulfonated polymer to form a mixture of said sulfonated polymer and said reactive plasticizer, said plasticizer being an ester of an α,β-unsaturated monocarboxylic acid; (b) adding a free radical catalyst to said mixture at a concentration level of at least about 0.05 parts per hundred by weight of said reactive plasticizer; (c) heating said mixture with said free radical catalyst to a first temperature for solvating said neutralized sulfonate groups with said reactive plasticizer; and (d) further heating said mixture with said reactive plasticizer to a second temperature sufficient to permit processability of said composition and to cause said free radical catalyst to polymerize said reactive plasticizer within said mixture, said second temperature being greater than said first temperature and above a decomposition temperature of said free radical catalyst.