摘要
A series of amphiphilic thermosensitive poly- phosphazenes (PNIPAm-g-PPP) bearing N-isopropylacryla- mide oligomers (oligo-PNIPAm) and glycine ethyl groups (GlyEt) as co-substituents have been synthesized via polymer substitute reaction. UV-visible spectra indicated that the aqueous solution of PNIPAm-g-PPP exhibited the lower critical solution temperature (LCST). Furthermore, the LCST was seriously influenced by the substitution ratios of PNIPAm to GlyEt in the copolymer. The more GlyEt the copolymer contained, the lower LCST it had. The critical association concentration (cac) of copolymers was deter- mined by fluorescence probe method. It was found that cac was decreased with increasing GlyEt content of polyphos- phazene. Also the formation of self-assembled micelles or nano-particles was confirmed by TEM.
A series of amphiphilic thermosensitive polyphosphazenes （PNIPAm-g-PPP） bearing N-isopropylacrylamide oligomers （oligo-PNIPAm） and glycine ethyl groups （GlyEt） as co-substituents have been synthesized via polymer substitute reaction. UV-visible spectra indicated that the aqueous solution of PNIPAm-g-PPP exhibited the lower critical solution temperature （LCST）. Furthermore, the LCST was seriously influenced by the substitution ratios of PNIPAm to GlyEt in the copolymer. The more GlyEt the copolymer contained, the lower LCST it had. The critical association concentration （cac） of copolymers was determined by fluorescence probe method. It was found that cac was decreased with increasing GlyEt content of polyphosphazene. Also the formation of self-assembled micelles or nano-particles was confirmed by TEM.
基金
the National Natural Science Foundation of China(Grant No.50203012)
关键词
缩聚磷酸盐
热敏材料
临界温度
胶状离子
polyphosphazene, thermosensitivity, lower critical solution temperature, micelle.
