Synthesis of Well-Defined Poly(N,N-diethylacrylamide)s End-Functionalized with Methacrylamide Structure by Means of Anionic Polymerization

Abstract

A specially designed N,N-dialkylmethacrylamide having a benzoyl chloride moiety in the N-alkyl chain (T) was prepared as a terminator for anionic polymerization of N,N-diethylacrylamide (DEA) to synthesize an end-functionalized polymer. Living poly(DEA) with narrow molecular weight distribution, which was produced by means of anionic polymerization of DEA with Ph2CHK in the presence of diethylzinc at 0 °C, reacted with T to afford an end-functionalized poly(DEA) carrying a methacrylamide group at the chain end. The end-group functionality of the polymer obtained was estimated to be up to 98% by 1H and 13C NMR and MALDI-TOF-MS analysis. However, the sufficient functionalization was not achieved because of side reactions when the living polymer generated with an organolithium initiator was used. Although the end-functionalized poly(DEA) is a macromonomer, neither polymerization nor oligomerization took place with any anionic initiator, but only a monoaddition product between them was obtained because N,N-disubstituted methacylamides are difficult to be polymerized. The end-functionalized poly(DEA) reacted with Ph2CHK equivalently to afford a well-defined anionic macroinitiator that initiates another anionic polymerization of DEA to yield a postpolymer consisting of two poly(DEA) blocks.