以4-氯甲基苯乙烯(CMS)为单体,CuCl/2,2′-联吡啶(bpy)为催化体系,通过原子转移自由基聚合反应(ATRP)制得超支化聚4-氯甲基苯乙烯(h -PCMS);再采用黄原酸钾对 h -PCMS表面的功能端基进行修饰,制得端基带有大量双硫酯基团的大分子链转移...以4-氯甲基苯乙烯(CMS)为单体,CuCl/2,2′-联吡啶(bpy)为催化体系,通过原子转移自由基聚合反应(ATRP)制得超支化聚4-氯甲基苯乙烯(h -PCMS);再采用黄原酸钾对 h -PCMS表面的功能端基进行修饰,制得端基带有大量双硫酯基团的大分子链转移剂(h -PCMS macro-CTA);通过可逆加成-断裂链转移聚合(RAFT)方法,以 h -PCMS macro-CTA依次引发甲基丙烯酸甲酯(MMA)和甲基丙烯酸丁酯(BMA)聚合制备星型多臂聚合物 h -PCMS 2300 - g -PMMA 5500 - b -PBMA 33000 ,分子量分布为1.6,其结构和性能经1H NMR,IR,GPC和DSC表征。展开更多
The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with in...The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with increase of chlorine content, the excimer emission band (~325nm)approaches to vanish, while the intensity of multi-ring aggregate emission band (~420nm) quicklyreaches a maximum, and then decreases sharply accompanied by appearance ofa new broad bandcentred at ca 488nm which roughly coincides with the typical emission band of hypercrossllinkedSt/DVB gels. Mearwhile, the result of IR measurement suggests that methylene bridge between phenylrings forms and increases with chloromethylation process. These results are explained in terms ofaside reaction of post-crosslinking, which densifies the loosely crosslinked networks and undoes thedensely entangled microgel nuclei. As a result, the morphology of the crosslinked gels becom es morehomogeneous with chloromethylation.展开更多
Amphiphilic graft copolymers are excellent additives for the development of antifouling membranes by nonsolvent induced phase separation. We report a convenient approach to the synthesis of novel graft copolymers with...Amphiphilic graft copolymers are excellent additives for the development of antifouling membranes by nonsolvent induced phase separation. We report a convenient approach to the synthesis of novel graft copolymers with hydrophobic polyacryloni- trile (PAN) backbones and hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) side chains. Atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate was carried out with poly(acrylonitrile-co-p-chloromethyl styrene) (PAN-co-PCMS) as a macroinitiator in the presence of CuC1/2,2'-bipyridine at 50 ~C in dimethyl sulfoxide. Kinetics of the graft polymerization was also evaluated. The synthesis of poly(acrylonitrile-co-p-chloromethyl styrene-g-2-hydroxyethyl methacrylate) (PAN-co-(PCMS-g-PHEMA)) can be relatively controlled when CMS (the ATRP sites) unit in the macroinitia- tor is around 5 mol%. Both the macroinitiators and graft copolymers were characterized by FTIR, NMR and GPC. The surface morphology and wettability of the copolymer films were studied by AFM and water contact angle measurement, respectively. We demonstrate that phase segregation between the PAN-co-PCMS backbones and the PHEMA side chains takes place and the surface hydrophilicity of the graft copolymers increases with the length of the PHEMA side chains. Because these am- phiphilic graft copolymers can be synthesized in mass, they will be useful as latent additives for the fabrication of advanced PAN separation membranes.展开更多
文摘以4-氯甲基苯乙烯(CMS)为单体,CuCl/2,2′-联吡啶(bpy)为催化体系,通过原子转移自由基聚合反应(ATRP)制得超支化聚4-氯甲基苯乙烯(h -PCMS);再采用黄原酸钾对 h -PCMS表面的功能端基进行修饰,制得端基带有大量双硫酯基团的大分子链转移剂(h -PCMS macro-CTA);通过可逆加成-断裂链转移聚合(RAFT)方法,以 h -PCMS macro-CTA依次引发甲基丙烯酸甲酯(MMA)和甲基丙烯酸丁酯(BMA)聚合制备星型多臂聚合物 h -PCMS 2300 - g -PMMA 5500 - b -PBMA 33000 ,分子量分布为1.6,其结构和性能经1H NMR,IR,GPC和DSC表征。
基金National Natural Scientific Foundation of China (Project grant No.29574165 29928003+1 种基金 29874019) National Natural Scientific Foundation of Tianjin (Project grant No.013604011)
文摘The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with increase of chlorine content, the excimer emission band (~325nm)approaches to vanish, while the intensity of multi-ring aggregate emission band (~420nm) quicklyreaches a maximum, and then decreases sharply accompanied by appearance ofa new broad bandcentred at ca 488nm which roughly coincides with the typical emission band of hypercrossllinkedSt/DVB gels. Mearwhile, the result of IR measurement suggests that methylene bridge between phenylrings forms and increases with chloromethylation process. These results are explained in terms ofaside reaction of post-crosslinking, which densifies the loosely crosslinked networks and undoes thedensely entangled microgel nuclei. As a result, the morphology of the crosslinked gels becom es morehomogeneous with chloromethylation.
基金supported by the National Natural Science Foundation of China (21174124)
文摘Amphiphilic graft copolymers are excellent additives for the development of antifouling membranes by nonsolvent induced phase separation. We report a convenient approach to the synthesis of novel graft copolymers with hydrophobic polyacryloni- trile (PAN) backbones and hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) side chains. Atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate was carried out with poly(acrylonitrile-co-p-chloromethyl styrene) (PAN-co-PCMS) as a macroinitiator in the presence of CuC1/2,2'-bipyridine at 50 ~C in dimethyl sulfoxide. Kinetics of the graft polymerization was also evaluated. The synthesis of poly(acrylonitrile-co-p-chloromethyl styrene-g-2-hydroxyethyl methacrylate) (PAN-co-(PCMS-g-PHEMA)) can be relatively controlled when CMS (the ATRP sites) unit in the macroinitia- tor is around 5 mol%. Both the macroinitiators and graft copolymers were characterized by FTIR, NMR and GPC. The surface morphology and wettability of the copolymer films were studied by AFM and water contact angle measurement, respectively. We demonstrate that phase segregation between the PAN-co-PCMS backbones and the PHEMA side chains takes place and the surface hydrophilicity of the graft copolymers increases with the length of the PHEMA side chains. Because these am- phiphilic graft copolymers can be synthesized in mass, they will be useful as latent additives for the fabrication of advanced PAN separation membranes.
