USE OF SUBSTITUTED ALLYLIC SULFIDES TO PREPARE END-FUNCTIONAL POLYMERS OF CONTROLLED MOLECULAR-WEIGHT BY FREE-RADICAL POLYMERIZATION

Substituted allylic sulfides 1b-f and 2d were utilized as chain-transfer agents to prepare low molecular weight polystyrene and poly(methyl methacrylate) capped with carboxy, hydroxy, trialkoxysilyl, or amino groups. End-functional polymers, prepared with ethyl alpha-(((carboxymethyl)thio)methyl)acrylate (2b) or alpha-(((carboxymethyl)thio)methyl)acrylic acid (11b), were capped with both a carboxy group and an acrylate moiety. Low molecular weight alpha,omega-dicarboxypolystyrene or poly(methyl methacrylate) were readily obtained by chain transfer with 11b. alpha-Hydroxy-omega-carboxy- and alpha,omega-dihydroxy-terminated polystyrene, poly(methyl methacrylate), and poly(butyl acrylate) were prepared with alpha-(((2-hydroxyethyl)thio)methyl)-acrylic acid (11d) and 2-hydroxyethyl alpha-(((2-hydroxyethyl)thio)methyl)acrylate (12d), respectively, while N-phthalimidoethyl alpha-(((2-hydroxyethyl)thio)methyl)acrylate (13d) was used to prepare polymers terminated at one end with hydroxy and at the other with a phthalamido group. H-1 NMR or IR spectroscopy, titration, or derivatization was used to confirm the presence of the end groups.