本文首先通过分子设计技术合成了一系列侧链长度可以控制的接枝乙烯基酯树脂 (接枝VER :BO g VER ,2 0 0 g VER ,390 g VER) ,并用它们与甲苯二异氰酸酯合成的聚氨酯脲 (PUU)形成同步互穿网络(SIN) .通过DSC、SEM等考察了接枝VER的结...本文首先通过分子设计技术合成了一系列侧链长度可以控制的接枝乙烯基酯树脂 (接枝VER :BO g VER ,2 0 0 g VER ,390 g VER) ,并用它们与甲苯二异氰酸酯合成的聚氨酯脲 (PUU)形成同步互穿网络(SIN) .通过DSC、SEM等考察了接枝VER的结构对PUU/接枝VERSIN的形态与力学性能的影响 .在PUU/BO g VERSIN中 ,BO g VER网络主要与PUU网络中的硬段相容和互穿 ;对于PUU/ 2 0 0 g VERSIN而言 ,2 0 0 g VER网络与PUU网络中的软段和硬段均有一定的相容性 .由于这两种SIN中两个网络间均有一定的相容性和互穿 ,故这类接枝网络能显著地增强PUU网络 ,使材料的力学性能有较大幅度的提高 .390 g VER网络本身存在的微相分离结构 ,使PUU/ 390 g VERSIN两个网络也存在显著的相分离形态 ,导致390 g VER网络对PUU网络的增强效果并不明显 .展开更多
The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven...The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven that C60 was grafted covalently to the PVK. The C60 moiety in the product was about 1. 2% (mass fraction). The photoconductlvity study revealed that the photoconductivity of PVK was improved obviously through grafting C60.The half time of light decaying (t1/2) of CGP reached 0. 35 s.展开更多
Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyry...Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyryl bromide(BriB-Br)to obtain efficient macroinitiator for ATRP.And the macroinitiator was grafted with HEMA in water aqueous using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine(PMDETA)as catalyst system.The effects of monomer concentration,the proportion of CuBr and PMDETA,grafting temperature and time on the silk grafting were discussed,and the optimal grafting technology was obtained.FT-IR characterization of the grafted silk showed a peak corresponding to HEMA,which indicated that HEMA was grafted onto the surface of silk.ATRP method could be applied on the silk modification and this technique provided a new way for silk grafting.展开更多
Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved signifi...Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.展开更多
With potassium persulfate (KPS) as initiator, graft copolymerization of ethyl acrylate (EA) onto water-soluble hydroxypropyl methylcellulose (HPMC) was investigated in aqueous medium. Effects of monomer concentration,...With potassium persulfate (KPS) as initiator, graft copolymerization of ethyl acrylate (EA) onto water-soluble hydroxypropyl methylcellulose (HPMC) was investigated in aqueous medium. Effects of monomer concentration, initiator concentration, matrix concentration, and reaction temperature on the percentage of grafting (G) and grafting efficiency (G_E) were studied. The results show that G and G_E values both increase with the the increase of EA concentration and KPS concentration; when raising HPMC concentration from 0.12 mmol/L to 0.47 mmol/L, G decreases, while G_E increases;and when raising reaction temperature from 50 ℃ to 65 ℃,G increases, but G_E decreases. In addition, the graft copolymers were characterized by Fourier transform infrared (FTIR) spectra and transmission electron microscopy (TEM) methods.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
文摘本文首先通过分子设计技术合成了一系列侧链长度可以控制的接枝乙烯基酯树脂 (接枝VER :BO g VER ,2 0 0 g VER ,390 g VER) ,并用它们与甲苯二异氰酸酯合成的聚氨酯脲 (PUU)形成同步互穿网络(SIN) .通过DSC、SEM等考察了接枝VER的结构对PUU/接枝VERSIN的形态与力学性能的影响 .在PUU/BO g VERSIN中 ,BO g VER网络主要与PUU网络中的硬段相容和互穿 ;对于PUU/ 2 0 0 g VERSIN而言 ,2 0 0 g VER网络与PUU网络中的软段和硬段均有一定的相容性 .由于这两种SIN中两个网络间均有一定的相容性和互穿 ,故这类接枝网络能显著地增强PUU网络 ,使材料的力学性能有较大幅度的提高 .390 g VER网络本身存在的微相分离结构 ,使PUU/ 390 g VERSIN两个网络也存在显著的相分离形态 ,导致390 g VER网络对PUU网络的增强效果并不明显 .
文摘The C60 grafted poly(N-vinyl carbazole) (PVK) polymer(CGP) was prepared by simple radical polymerization initiated by BPO at 90℃.The products were characterized by UV-Vis, FTIR, GPC and fluorescence and it was proven that C60 was grafted covalently to the PVK. The C60 moiety in the product was about 1. 2% (mass fraction). The photoconductlvity study revealed that the photoconductivity of PVK was improved obviously through grafting C60.The half time of light decaying (t1/2) of CGP reached 0. 35 s.
基金National Natural Science Foundation of China(No.50673071,No.50973079)Natural Science Fund for Colleges and Universities in Jiangsu Province,China(No.07KJD540188,No.09KJA540001)
文摘Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyryl bromide(BriB-Br)to obtain efficient macroinitiator for ATRP.And the macroinitiator was grafted with HEMA in water aqueous using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine(PMDETA)as catalyst system.The effects of monomer concentration,the proportion of CuBr and PMDETA,grafting temperature and time on the silk grafting were discussed,and the optimal grafting technology was obtained.FT-IR characterization of the grafted silk showed a peak corresponding to HEMA,which indicated that HEMA was grafted onto the surface of silk.ATRP method could be applied on the silk modification and this technique provided a new way for silk grafting.
基金This project is supported by Natural Science Foundation of College of Jiangsu Province , China (02KJA540001)
文摘Silk fibers were grafted with a novel vinyl siloxane monomer. The properties of silk with different grafting yield were discussed. The results showed that the crease recovery of grafted silk fabric is improved significantly, handle of grafted silk is softer, and grafting has no influence on strength of silk. Graft with low grafting yield has no effect on dyeing properties of silk. The results of IR, SEM photographs and amino acid analysis indicate that the monomer combines with silk fiber by physical sediment and chemical bond, the grafting reactions mainly occurred on Ser., His. and Arg. of silk fibers, and ester crosslinking forms between silanol and Asp., Gin. of silk molecular side chains. X-ray diffraction patterns of silk fibers suggest that the grafting has no effect on the crystalline regions.
文摘With potassium persulfate (KPS) as initiator, graft copolymerization of ethyl acrylate (EA) onto water-soluble hydroxypropyl methylcellulose (HPMC) was investigated in aqueous medium. Effects of monomer concentration, initiator concentration, matrix concentration, and reaction temperature on the percentage of grafting (G) and grafting efficiency (G_E) were studied. The results show that G and G_E values both increase with the the increase of EA concentration and KPS concentration; when raising HPMC concentration from 0.12 mmol/L to 0.47 mmol/L, G decreases, while G_E increases;and when raising reaction temperature from 50 ℃ to 65 ℃,G increases, but G_E decreases. In addition, the graft copolymers were characterized by Fourier transform infrared (FTIR) spectra and transmission electron microscopy (TEM) methods.
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.
