Branched polymer via free radical polymerization of chain transfer monomer: A theoretical and experimental investigation

作者：Liu Jianhua; Wang Yusong; Fu Qi; Zhu Xiangyang; Shi Wenfang^*

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2008, 46(4): 1449-1459.

DOI：10.1002/pola.22484

• chain transfer
• highly branched
• hyperbranched
• modeling
• polystyrene
• radical polymerization

A simple mathematic model for the free radical polymerization of chain transfer monomers containing both polymerizable vinyl groups and telogen groups was proposed. The molecular architecture of the obtained polymer can be prognosticated according to the developed model, which was validated experimentally by homopolymerization of 4-vinyl benzyl thiol (VBT) and its copolymerization with styrene. The chain transfer constant (C-T) of telogen group in a chain transfer monomer is considered to play an important role to determine the architecture of obtained polymer according to the proposed model, either in homopolymerization or copolymerization. A highly branched polymer will be formed when the C-T value is around unity, while a linear polymer with a certain extent of side chains will be obtained when the C-T value is much bigger or smaller than unity. The C-T of VBT was determined to be around 15 by using the developed model and H-1 NMR monitored experiments. The obtained poly(VBT) and its copolymers were substantiated to be mainly consisted of linear main chain with side branching chains, which is in agreement with the anticipation from the developed model. The glass transition temperature, number average molecular weight, and its distribution of those obtained polymer were primarily investigated. This model is hopefully to be used as a strategy to select appropriate chain transfer monomers for preparing hyperbranched polymers.

• 出版日期2008-2-15
• 单位中国科学技术大学