The platelet adhesion and protein(Fibrinogen and albumin) adsorption ontoamphiphilic polystyrene-graft-poly(ethylene oxide) (PS-g-PEO) and polystyrene-graft -ω-stearyl-poly(ethyleneoxide) (PS-G-SPEO) were investigate...The platelet adhesion and protein(Fibrinogen and albumin) adsorption ontoamphiphilic polystyrene-graft-poly(ethylene oxide) (PS-g-PEO) and polystyrene-graft -ω-stearyl-poly(ethyleneoxide) (PS-G-SPEO) were investigated. It was found that the plateletadhesion on PS-g-SPEO was lower than that on PS-g-PEO. The PS-g-SPEO surface shows apreference for Albumin, while the PS-g-PEO surface absorbed Fibrinogen selectivelyu. Twoeffects of stearyl end group on PS-g-SPEO surface: (1) the lower surface free energe leadsto SPEO enrich at surface; (2) the stearyl end group absorbed albumin selectively, seems tocontribute to resistant the platelet adhesion. So the polymer surface modificed by both stearylgroup and poly(ethylene oxide) chain may be a new ideal way to improve material’s bloodcompatibility.展开更多
Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (e...Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.展开更多
用ESR方法对TiCl_3、TiCl_3-AlR_3体系及TiCl_3-AlR_3-1-辛烯体系进行了跟踪研究,并研究了预聚对ESR信号的影响。发现络合Ⅱ型TiCl_3-AlR_3-1-辛烯体系存在三种顺磁中心,且三种顺磁中心都是聚合活性中心。预聚并不改变该体系活性中心的...用ESR方法对TiCl_3、TiCl_3-AlR_3体系及TiCl_3-AlR_3-1-辛烯体系进行了跟踪研究,并研究了预聚对ESR信号的影响。发现络合Ⅱ型TiCl_3-AlR_3-1-辛烯体系存在三种顺磁中心,且三种顺磁中心都是聚合活性中心。预聚并不改变该体系活性中心的种类和结构。还发现Stauffer AA TiCl_3-AlE_3-1-辛烯体系中多种活性中心并存的现象与络合Ⅱ型TiCl_3-AlEt_3-1-辛烯体系无本质区别。展开更多
文摘The platelet adhesion and protein(Fibrinogen and albumin) adsorption ontoamphiphilic polystyrene-graft-poly(ethylene oxide) (PS-g-PEO) and polystyrene-graft -ω-stearyl-poly(ethyleneoxide) (PS-G-SPEO) were investigated. It was found that the plateletadhesion on PS-g-SPEO was lower than that on PS-g-PEO. The PS-g-SPEO surface shows apreference for Albumin, while the PS-g-PEO surface absorbed Fibrinogen selectivelyu. Twoeffects of stearyl end group on PS-g-SPEO surface: (1) the lower surface free energe leadsto SPEO enrich at surface; (2) the stearyl end group absorbed albumin selectively, seems tocontribute to resistant the platelet adhesion. So the polymer surface modificed by both stearylgroup and poly(ethylene oxide) chain may be a new ideal way to improve material’s bloodcompatibility.
基金Supported by the National Natural Science Foundation of China and the State Education Committee of China
文摘Acryloyl terminated Poly (ethyleneoxide)macromonomers (PEO-A) with different PEO chain lengths have been prepared by deactivation of PEO alkoxide with acryloyl chloride. A new kind of amphiphilic polystyrene-g-poly (ethylene oxide)graft copolymer containing both microphase separated and PEO side chain structures has been synthesized from radical copolymerization of PEO-A macromonomer with styrene. After careful purification by a newly-developed method called 'selective dissolution', the well-defined structure of the purified copolymers was confirmed by IR, ~1H-NMR and GPC. Various experimental parameters controlling the copolymerization were studied in detail. The results indicated that the feed ratio of styrene to macromonomer(S/M) was the most important determining factor for the composition of the copolymers. A detailed 'comb- model' was proposed to describe the molecular structure of the graft copolymers. Finally, this amphiphilic graft copolymers may readily form microphase separated structures as clearly indicated by transmission electron microscopy.
文摘用ESR方法对TiCl_3、TiCl_3-AlR_3体系及TiCl_3-AlR_3-1-辛烯体系进行了跟踪研究,并研究了预聚对ESR信号的影响。发现络合Ⅱ型TiCl_3-AlR_3-1-辛烯体系存在三种顺磁中心,且三种顺磁中心都是聚合活性中心。预聚并不改变该体系活性中心的种类和结构。还发现Stauffer AA TiCl_3-AlE_3-1-辛烯体系中多种活性中心并存的现象与络合Ⅱ型TiCl_3-AlEt_3-1-辛烯体系无本质区别。
