Synthesis of Functional Comb-block-Comb Copolymers Based on RAFT and Click Chemistry and their Self-assembly
The preparation of comb block comb (CBC) copolymers are based on three-step synthetic strategies as shown in Scheme 1: (1) the synthesis of pyrenyl-Br, pyrenyl-N3 and macromolecular CTA (macro-CTA) poly (poly (ethylene glycol) methacrylate) (PPEGMA) by RAFT, (2) the synthesis of clickable CBC copolymers by RAFT of propargyl methacrylate (PgMA), (3) the click coupling of precursors containing antagonistfunctionalities. The chain transfer agent (CTA) (4-cyanopentanoic acid)-4-dithiobenzoate (CPADB) wasprepared by using a method similar to a literature,l and (4-propargyl cyanopentanate)-4-dithiobenzoate was synthesized by esterfication of PgOH with CPADB. The resulting CTA was used to prepare PPEGMA by RAFT at 60℃ in DMF for 16h. PgMA monomer was prepared by a reaction of propargyl alcohol (PgOH) with methacryloyl chloride in the presence of triethylamine. By using the resulting PPEGMA as macro-CTA,clickable acetylene copolymers were synthesized with PgMA at 60℃ in DMF. GPC analysis of the product demonstrated high CTA efficiency and well-controlled polymerization. The corresponding clickable product was then click coupled with pyrenyl-N3 in DMF at room temperature in the presence of CuBr and PMDETA. After 24h of reaction the targeted CBC copolymers were obtained. GPC traces showed a clear shift towards the higher molecular weight region after click chemistry in comparison with the starting polymer.
Xiwen Zhang Li Liu Xueming Lian Jian Zhang Hanying Zhao
Key Laboratory of Functional Polymer Materials,Ministry of Education,Institute of Polymer Chemistry,Department of Chemistry,Nankai University,Tianjin 300071,China
国际会议
5th East-Asian Polymer Conference(第5届东亚高分子学术研讨会)
上海
英文
206-207
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）