Synthesis of Star Block Copolymers from Dendrimer Initiators by Combining Ring-Opening Polymerization and Atom Transfer Radical Polymerization
Synthesis of Star Block Copolymers from Dendrimer Initiators by Combining Ring-Opening Polymerization and Atom Transfer Radical Polymerization
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DOI：
10.1021/ma048303r
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发表时间：
2004-10
期刊：
影响因子：
5.5
通讯作者：
Youliang Zhao;X. Shuai;and Chuanfu Chen;F. Xi
中科院分区：
文献类型：
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作者：
Youliang Zhao;X. Shuai;and Chuanfu Chen;F. Xi
在聚芳醚枝状大分子（CMGn-OH, n = 1−3，官能团分别为6、12和24）的基础上，通过活开环聚合（ROP）和原子转移自由基聚合（ATRP）相结合，成功合成了24臂的树状星形嵌段共聚物。以l-丙交酯为原料，以多功能枝状大分子引发剂和八酸锡为催化剂，通过本体聚合合成了星型聚丙交酯（CMGn-PLLA）。随着单体转化率的增加，CMGn-PLLA的分子量呈线性增加，分子量分布保持在1.15以下，表明聚合具有活性。cmn - plla通过与2-溴异丁基溴的酯化反应转化为大型引发剂cmn - plabr。采用CMGn-PLLABr/CuBr/五甲基二乙烯三胺引发体系对甲基丙烯酸甲酯（MMA）和苯乙烯（St）进行ATRP，得到了分子量预定且分子量分布窄(1.05 < Mw/…
Well-defined dendrimer-like star block copolymers up to 24 arm were successfully achieved by combination of living ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) on the basis of poly(aryl ether) dendrimers (CMGn-OH, n = 1−3, with functionality of 6, 12, and 24, respectively). Star polylactides (CMGn-PLLA) were synthesized by bulk polymerization of l-lactide with multifunctional dendrimer initiators and stannous octoate catalyst. The molecular weights of CMGn-PLLA increased linearly with increasing monomer conversion, with molecular weight distributions remaining below 1.15, indicating the living nature of polymerization. CMGn-PLLA was converted into a macroinitiator CMGn-PLLABr via esterification with 2-bromoisobutyryl bromide. ATRP of methyl methacrylate (MMA) and styrene (St) using the CMGn-PLLABr/CuBr/pentamethyldiethylenetriamine initiating system afforded star block copolymers with predetermined molecular weights and narrow molecular weight distributions (1.05 < Mw/...