School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, China.
Macromol Rapid Commun. 2012 Mar 16;33(5):374-9. doi: 10.1002/marc.201100825. Epub 2012 Jan 24.
A novel polymerization methodology for efficient synthesis of hyperbranched polyethylene amphiphiles by chain walking polymerization (CWP) followed by RAFT polymerization has been developed. Hyperbranched polyethylene with hydroxyl ends (HBPE-OHs) is first synthesized via chain walking copolymerization of ethylene with 2-hydroxyethyl acrylate with Pd-α-diimine catalyst. The hydroxyl groups of hyperbranched polyethylene are then converted into thiocarbonyl thio moieties by an esterification reaction with trithiocarbonate 3-benzylsulfanylthiocarbonyl sulfanylpropionic acid (BSPA). The hyperbranched polyethylene with thiocarbonyl thio moiety ends (HBPE-BSPAs) is used as a macro-RAFT agent for the synthesis of hyperbranched polyethylene amphiphiles, HBPE-PDMAEMAs, by RAFT polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA). The resultant HBPE-PDMAEMAs can self-assemble to form supramolecular polymer vesicles in aqueous solution. A preliminary investigation on thermo- and pH-responsive behaviors of the polymer is also reported.
一种通过链行走聚合(CWP)随后进行 RAFT 聚合来高效合成超支化聚乙烯两亲物的新型聚合方法已经开发出来。首先通过钯-α-二亚胺催化剂使乙烯与 2-羟乙基丙烯酸酯进行链行走共聚合成具有羟基末端的超支化聚乙烯(HBPE-OHs)。然后通过与三硫代碳酸酯 3-苄基硫代羰基硫代羰基丙硫酸(BSPA)的酯化反应将超支化聚乙烯的羟基转化为硫代羰基硫代部分。具有硫代羰基硫代部分末端的超支化聚乙烯(HBPE-BSPAs)用作大分子 RAFT 试剂,通过 N,N-二甲基氨基乙基甲基丙烯酸酯(DMAEMA)的 RAFT 聚合来合成超支化聚乙烯两亲物 HBPE-PDMAEMAs。所得的 HBPE-PDMAEMAs 可以自组装在水溶液中形成超分子聚合物囊泡。还报告了对聚合物的热和 pH 响应行为的初步研究。