Well-Defined Glycopolymer Amphiphiles for Liquid and Supercritical Carbon DIoxide Applications

摘要

Well-defined D-glucose-containing glycopolymers, poly(3-O-methacryloyl-1,2 : 5,6-di-O-isopropylidene-D-glucofuranose) (PMAIpGlc), and diblock copolymers of PMAIpGlc with poly(1,1-dihydroperfluorooctyl methacrylate) (PFOMA) were synthesized by living anionic polymerizaiton in THF at -78 deg C with 1,1-diphenylhexyllithium in the presence of lithium chloride. The resulting polymers were found to possess predicable molecular weights and very narrow molecular weight distributions (MWD, M_w/M_n <= 1.16). Removal of the acetal protective groups fromthe protected glycopolymer block copolymer was carried out uisng 90 % trifluoroacetic acid at room temperature, yielding a hydrophilic block copolymer with pendant glucose moieties. Both protected (lipophilic/CO_2-philic) and deprotected (hydrophilic/CO_2-philic) fluorocopolymers were proved to be CO_2 amphiphilies. Their solubility in CO_2 was heavily influenced by the amphiphilic structure, such as the copolymer compositions and the polarities of sugar block. Light-scattering studies showed that, after removal of the jprotective groups, the deprotected block copolymer formed aggregate structures in liquid CO_2 with an average micellar size of 27 nm.