含聚己内酯臂的超支化聚乙烯的合成及在正己烷中的自组装

摘要

通过结合“链行走”聚合和开环聚合，合成了一系列含聚酯臂的超支化聚乙烯( HBPE-PCLs)。首先使用α-二亚胺钯催化剂催化乙烯与极性单体HEA进行“链行走”共聚合，经脱保护得到结构明确的末端羟基超支化聚乙烯( HBPE-OH)，然后以HBPE-OH为大分子引发剂，引发己内酯(ε-CL)单体开环聚合，合成了一系列含聚酯臂超支化聚乙烯( HBPE-PCLs)。通过观察该聚合在正己烷中的自组装行为，发现其可以形成典型的囊泡结构，这种油中形成的囊泡在油溶性药物的运输与释放中存在着潜在的应用。%A novel polyolefin copolymer HBPE-PCLs with a hyperbranched polyethylene core and poly (ε-caprolac-tone) arms was successfully prepared via a combination of chain walking polymerization(CWP) and ring-opening polymerization(ROP). Hyperbranched polyethylene with hydroxyl ends(HBPE-OH) was firstly synthesized via the chain walking copolymerization of ethylene with 2-hydroxyethyl acrylate in the presence of Pd-α-diimine catalyst. The HBPE-OH was used as the macroinitior for ROP of ε-caprolactone to synthesize hyperbranched polyethylene copoly-mer HBPE-PCLs. Investigations of self-assembly of the HBPE-PCLs copolymer in n-hexane by means of transmission electron microscopy ( TEM ) , scanning electran microscopy ( SEM ) and laser light scattering confirm that the copolymer formed vesicles in nonpolar organic solution. The vesicles are the organic counterparts to vesicles in aqueous solution and could potentially find analogous application in the encapsulation of drug and controlled release.