Polyisobutylene-based block anionomers and cationomers and synthesis thereof

摘要

Various novel block cationomers comprising polyisobutylene (PIB) and poly(2-dimethylamino)ethyl methacrylate) (PDMAEMA) segments have been synthesized and characterized. The specific targets were various molecular weight diblocks (PDMAEMA⁺) and triblocks (PDMAEMA⁺-b-PIB-b-PDMAEMA⁺) with the PIB blocks in the DP_n=50-200 (M_n=3,000-9,000 g/mol) range connected to blocks of PDMAEMA⁺ cations in the DP_n=5-20 range. The overall synthetic strategy for the preparation of these block cationomers comprised four steps: 1) Synthesis by living cationic polymerization of mono- and di-allyltelechelic polyisobutylenes, 2) End group transformation to obtain PIBs fitted with termini capable of mediating the atom transfer radical polymerization (ATRP) of DMAEMA, 3) ATRP of DMAEMA and 4) Quaternization of PDMAEMA to PDMAEMA⁺I⁻ by CH₃I. Kinetic and model experiments provided guidance to develop convenient synthesis methods. The microarchitecture of PIB-PDMAEMA di- and triblock and the corresponding block cationomers were confirmed by ¹H NMR and FTIR spectroscopy and solubility studies.