|233. Martínez-Castro, N.; Zhang, M.; Pergushov, D.V.; Müller, A.H.E.: Anionic Polymerization of N,N-Dimethylacrylamide with Thienyllithium and Synthesis of Block Copolymers of Isobutylene and N,N-Dimethylacrylamide by Site Transformation of Chain Ends, Designed Monomers and Polymers 9, 63-79 (2006)|
The anionic polymerization of N,N-dimethylacrylamide (DMAAm) was carried out in THF with a binary initiator system prepared from thienyllithium and the Lewis acids triethylaluminium (Et3Al), diethylzinc (Et2Zn) or triethylborane (Et3B). Polymerizations proceeded in a homogeneous manner and gave polymers having controlled molecular weights. However, in presence of alkoxides the polymerization results in polymers insoluble in THF even using Et3Al. A synthetic route for the synthesis of polyisobutylene-b-PDMAAm was developed by combining living carbocationic and anionic polymerizations. Thiophene end-capped polyisobutylene (PIB-T), prepared by cationic polymerization, was metalated with n-butyllithium in THF at 40 °C. The resulting stable macrocarbanion (PIB-T-, Li+), in conjunction with Lewis acids, was used to initiate the living anionic polymerization of DMAAm, resulting in the new amphiphilic block copolymer PIB-b-PDMAAm. Their molecular structure was characterized by size exclusion and adsorption chromatography and NMR and their micellisation in aqueous solution was characterized by fluorometry and dynamic light scattering.