A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxy...A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxyl poly(ethylene oxide) with pendant acetal protected hydroxyl groups (l-poly(EO-co-EEGE)) was prepared first by the anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE).Then l-poly(EO-co-EEGE) was cyclized.The crude cyclized product containing the linear byproduct was hydrolyzed and purified by being treated with α-CD.The pure cyclic copolymer [c-poly(EO-co-Gly)] was esterified by reaction with 2-bromoisobutyryl bromide,and then used as ATRP macroinitiators to initiate polymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA),and a series of pH-and temperature-sensitive macrocyclic graft copolymers composed of a hydrophilic PEO as the ring and PDMAEMA as side chains (c-PEO-g-PDMAEMA) were obtained.The behavior of pH-and temperature-sensitive macrocyclic copolymers was studied in aqueous solution by fluorescence and dynamic light scattering (DLS).The critical micellization pH values of macrocyclic graft copolymers and their corresponding linear graft copolymers (l-PEO-g-PDMAEMA) were measured.Under the same conditions,the cyclic graft copolymer with the shorter side chains gave the higher critical micellization pH value.The c-PEO-g-PDMAEMA showed the lower critical micellization pH value than the corresponding l-PEO-g-PDMAEMA.The average hydrodynamic diameters (Dh) of the micelles were measured by DLS with the variation of the aqueous solution pH value and temperature.展开更多
Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-l,2-propanediol, and after subsequently alcoholyzed, α-{3-[（2,3-d...Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-l,2-propanediol, and after subsequently alcoholyzed, α-{3-[（2,3-dihydroxy）propoxy]propyl}-ω- butyl-polydimethylsiloxanes with varying number of （（Si（CH3）2-O） unit were obtained. At each step, the produced compounds were carefully characterized. The results showed that each step was successfully carried out and target products were achieved.展开更多
α-{ 3-[2-hydroxy-3-（N-methyl-N-hydroxyethylamino）propoxy]propyl }-α-butylpolydimethylsiloxanes III with various molecu- lar weights were prepared by epoxy addition of α-[3-（2,3-epoxy-propoxy）propyl]-α-butylpol...α-{ 3-[2-hydroxy-3-（N-methyl-N-hydroxyethylamino）propoxy]propyl }-α-butylpolydimethylsiloxanes III with various molecu- lar weights were prepared by epoxy addition of α-[3-（2,3-epoxy-propoxy）propyl]-α-butylpolydimethylsiloxanes Ⅱ and N- methylmonoethanolamine. At each step, the outcome compounds were characterized through FT-IR and NMR spectra, the results showed that each step was successfully carried out and objective products were achieved.展开更多
基金support from the National Natural Science Foundation of China (20874013)
文摘A novel method for the synthesis of macrocyclic graft copolymers was developed through combination of anionic ring-opening polymerization (AROP) and atom transfer radical polymerization (ATRP).A linear α,ω-dihydroxyl poly(ethylene oxide) with pendant acetal protected hydroxyl groups (l-poly(EO-co-EEGE)) was prepared first by the anionic copolymerization of ethylene oxide (EO) and ethoxyethyl glycidyl ether (EEGE).Then l-poly(EO-co-EEGE) was cyclized.The crude cyclized product containing the linear byproduct was hydrolyzed and purified by being treated with α-CD.The pure cyclic copolymer [c-poly(EO-co-Gly)] was esterified by reaction with 2-bromoisobutyryl bromide,and then used as ATRP macroinitiators to initiate polymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA),and a series of pH-and temperature-sensitive macrocyclic graft copolymers composed of a hydrophilic PEO as the ring and PDMAEMA as side chains (c-PEO-g-PDMAEMA) were obtained.The behavior of pH-and temperature-sensitive macrocyclic copolymers was studied in aqueous solution by fluorescence and dynamic light scattering (DLS).The critical micellization pH values of macrocyclic graft copolymers and their corresponding linear graft copolymers (l-PEO-g-PDMAEMA) were measured.Under the same conditions,the cyclic graft copolymer with the shorter side chains gave the higher critical micellization pH value.The c-PEO-g-PDMAEMA showed the lower critical micellization pH value than the corresponding l-PEO-g-PDMAEMA.The average hydrodynamic diameters (Dh) of the micelles were measured by DLS with the variation of the aqueous solution pH value and temperature.
基金supported by the National Natural Science Foundation of China(No.20576117 and No.20836007)
文摘Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-l,2-propanediol, and after subsequently alcoholyzed, α-{3-[（2,3-dihydroxy）propoxy]propyl}-ω- butyl-polydimethylsiloxanes with varying number of （（Si（CH3）2-O） unit were obtained. At each step, the produced compounds were carefully characterized. The results showed that each step was successfully carried out and target products were achieved.
基金the Natural Science Foundation of Shandong Province(No.Y2006B22).
文摘α-{ 3-[2-hydroxy-3-（N-methyl-N-hydroxyethylamino）propoxy]propyl }-α-butylpolydimethylsiloxanes III with various molecu- lar weights were prepared by epoxy addition of α-[3-（2,3-epoxy-propoxy）propyl]-α-butylpolydimethylsiloxanes Ⅱ and N- methylmonoethanolamine. At each step, the outcome compounds were characterized through FT-IR and NMR spectra, the results showed that each step was successfully carried out and objective products were achieved.
