文献类型：期刊文献

英文题名：Synthesis of ABA block copolymers by means of 'living'/controlled radical polymerization using hydroxyl-terminated oligomers as precursor

作者：Wang, Xiao-Song[1]; Luo, Ning[1]; Ying, Sheng-Kang[1]; Liu, Qing[1]

机构：[1] Laboratory of Living Polymerization, E. China Univ. Sci. Technol., 130 M., Shanghai, China

年份：2000

卷号：36

期号：1

起止页码：149

外文期刊名：European Polymer Journal

收录：EI(收录号：2000405300688)

语种：英文

外文关键词：Free radical polymerization - Hydroxylation - Infrared spectroscopy - Initiators (chemical) - Molecular weight distribution - Nuclear magnetic resonance spectroscopy - Oligomers - Polybutadienes - Polyesters - Polyethers - Reaction kinetics - Synthesis (chemical)

摘要：ABA block copolymers with well-defined structure were synthesized by the combination of the end-group transformation of prefabricated hydroxyl-terminated oligomers and atom transfer radical polymerization (ATRP). The hydroxyl-terminated oligomers, such as polyether diol, polyester diol and hydroxyl-terminated polybutadiene, were reacted with chloroacetyl chloride to form α,ω-bichloroacetyl oligomers (P-Cl). After the P-Cl was characterized by IR and chlorine content analysis, it was used as macro-initiator in the bulk polymerization of styrene in the presence of CuCl/bpy, which led to a series of ABA block copolymers. The formation of block copolymers was proved by 1H-NMR. The molecular weight of the block copolymers could be designed up to 105 according to the consumed monomer and the amount of feeding P-Cl. The kinetic study showed that the relationship between the logarithm of monomer concentration and the reaction time was linear, and an induction period was observed. It suggested that the initiation is slow and the concentration of active species was constant after initiation. Moreover, the experimental molecular weight increased linearly with the monomer conversion; simultaneously, the molecular weight distribution (MWD) of the block copolymer was close to the MWD of the macro-initiator (P-Cl). The results demonstrate the polymerization is a 'living'/controlled process.