Group transfer polymerization of methyl methacrylate and butyl acrylate in tetrahydrofuran with oxy anions as catalysts

Abstract

AbstractGroup transfer polymerization (GTP) of methyl methacrylate (MMA) and butyl acrylate (BA) in tetrahydrofuran with (1‐methoxy‐2‐methyl‐1‐propenyloxy)trimethylsilane (MTS) as initiator and tetrabutylammonium 3‐chlorobenzoate, tetrabutylammonium bi‐3‐chlorobenzoate and tetrabutylammonium bibenzoate as catalysts was investigated. It was found, that the reaction of MTS with all catalysts in the absence of monomers yields the same reaction products as common GTP catalysts. Furthermore, the time‐conversion curves of MMA and BA exhibit induction periods proving the assumption, that the first addition step of the monomer to the initiator is slower than the propagation reaction. With respect to molecular‐weight control, oxy anions are superior to tetrabutylammonium cyanide (TBACN) due to the missing capability of oxy anions to initiate an anionic polymerization, and bobenzoates are to be preferred to monobenzoates. It is discussed, that the reaction behaviour of oxy anions in GTP can also be understood on the basis of enolate anions as active polymerization species.