Patent ID: 7834113

Claim:
A process consisting essentially of: (a) polymerizing a substituted styrene monomer of formula I, in the presence of a solvent, a chain transfer agent, and a free radical initiator to form a reaction mixture comprising substituted styrene polymer containing chain transfer derived end groups, wherein the weight ratio of monomer to solvent is about 1:1 to about 2:1; and wherein: R is —C(O)R 5 or —R 5 ; and R 1 and R 2 are the same or different and independently selected from a group consisting of H, F, Cl, Br, C 1 -C 4 alkyl, C 1 -C 4 fluoroalkyl, phenyl and tolyl; and R 5 is C 1 -C 5 alkyl, either straight chain or branched (b) removing unreacted monomer from the reaction mixture, and (c) reacting the substituted styrene polymer with a radical initiator and a salt of hypophosphorous acid to form a second reaction mixture.