STABILIZATION OF THE LIVING END IN THE ANIONIC-POLYMERIZATION OF 2-(TRIMETHYLSILOXY)ETHYL METHACRYLATE - ROLE OF SURROUNDING MONOMER MOLECULES

In an anionic polymerization of 2-(trimethylsiloxy)ethyl methacrylate (ProHEMA), the loading rate of the monomer was found to influence the polymerization. When the monomer loading was run quickly via a droppin g funnel, the ProHEMA polymerization occurred quantitatively to form p oly(ProHEMA) with a narrow molecular weight distribution (MWD). Based on the results, we propose a mechanism in which monomer molecules surr ounding the propagating species take part, viz, the surrounding monome r molecules prevent a possible termination reaction. In the presence o f LiCl for ProHEMA polymerization, a polymer with a rather narrower MW D was obtained.