摘要
以HTEMPO(2,2,6,6-四甲基-4-羟基哌啶-1-氧自由基)和TMPD(2,2,6,6-四甲基哌啶酮)为调控介质,以Irgacure 651为引发剂,研究了甲基丙烯酸甲酯(MMA)光聚合体系的控制反应动力学,比较了单分子(HTEMPO为调控介质)和双分子(HTEMPO和TMPD为调控介质)调控体系,并讨论了HTEMPO和HTEM-PO/TMPD在MMA光聚合体系中的调控作用、光敏化作用和原位光氧化反应.结果表明,对MMA光聚合体系,以HTEMPO/TMPD为控制介质的双分子调控体系是有效的,获得了良好的ln([M0]/[M])与时间,数均分子量与转化率之间的线性动力学关系,并且PMMA均聚物的多分散性指数(PD I)随着转化率的提高而减小.在高转化率(>85%)下,体系的多分散性指数(PD I)最小值可达到1.2.
Controlled/living photopolymerization of methyl methacrylate（MMA） mediated by bimolecular systems for 4-hydroxy-2,2,6,6-tetramethyl-piperidinyl- 1 -oxyl （HTEMPO） and 2,2,6,6-tetramethyl-piperidinone （TMPD） was performed at ambient temperature. The effects of HTEMPO, TMPD and their different molar ratio as a mediator and photo-induced oxidization in situ of TMPD in the system were discussed respectively. It is shown that the molecular weight （Mn ） of MMA homopolymer increased linearly and the polydispersity index （PDI） decreases with the conversion increasing, even until the conversion up to 80% , mediated by bimoleeular system with both HTEMPO and TMPD, which is the characteristic of a controlled/living free radical polymerization. It is found that the obtained MMA homopolymer prepared by the photopolymerization exhibited a narrow molecular weight distribution as was characterized by GPC, the smallest value of PDI is 1.2. The result also shows that the bimolecular systems with HTEMPO/TMPD as a mediator has a better controlling kinetic performance than that only mediated by HTEMPO under the same condition.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第1期192-195,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20474036)
教育部科学技术重大研究项目(批准号:02114)
广东省自然科学基金(批准号:021241)资助
