Atom transfer radical polymerizations （ATRPs） of styrene （St） in bulk initiated by six iniferter reagents were carried out, respectively, in the present of copper （1） bromide （CuBr） and N, N,N＇,N＂,N＂-pentam...Atom transfer radical polymerizations （ATRPs） of styrene （St） in bulk initiated by six iniferter reagents were carried out, respectively, in the present of copper （1） bromide （CuBr） and N, N,N＇,N＂,N＂-pentamethyldiethylenetriamine （PMDETA） at 115℃. All the kinetic plots were first-order with respect to the monomer concentrations. At the same time, the corresponding molecular weights of the polymers increased linearly with the respective monomer conversions. Furthermore, the molecular weight distributions remained relatively narrow （Mw/Mn〈1.50） in all cases. Solution ATRP of St in dimethyl- formamide （DMF） initiated by benzyl N, N-diethyldithiocarba- mate （BDC） also showed the characteristics of living radical polymerization. The results of 1H NMR analysis and chain extension experiment confirmed that the well-defined polystyrene （PS） bearing photo-liable group has been obtained via ATRP of St using photoiniferter reagents as the initiators.展开更多
The polymerization behaviors of Styrene (St) in the presence of CuX/L [X=Cl or Br; L= 2,2 bipyridine (bpy), 1,10 phenanthroline (phen) or 4,7 diphenyl 1,10 phenanthroline (DPP) ] and R X (R=trichloromethyl, benz...The polymerization behaviors of Styrene (St) in the presence of CuX/L [X=Cl or Br; L= 2,2 bipyridine (bpy), 1,10 phenanthroline (phen) or 4,7 diphenyl 1,10 phenanthroline (DPP) ] and R X (R=trichloromethyl, benzyl or allyl; X=Cl or Br) have been studied and examined. In a CuCl/bpy/RCl/St system, a bimodal GPC peak at the early stage of polymerization was observed, and a concept of multi active species was proposed to explain this phenomenon. In a CuCl/phen (DPP)/RCl/St system, the \%M\%\-n of polystyrene (PS) increased linearly with St conversion and ln[M] o/[M] also increased linearly with time, indicating the living nature of this system. Furthermore, the stability of the propagating active species in a CuBr/phen/RBr/St system is higher than that in the CuBr/phen/RBr/St system.展开更多
'Living'/controlled radical polymerization of styrene was carried out with diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS)/CuCl2/bipyridine (bipy) initiation system at 120 degreesC. The molecular weights of ...'Living'/controlled radical polymerization of styrene was carried out with diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS)/CuCl2/bipyridine (bipy) initiation system at 120 degreesC. The molecular weights of resultant PSt increased with the monomer conversion and the polydispersities were in the range of 1.37 similar to1.52. A linear ln([M](o)/[M]) versus time plot was also obtained indicating the constant concentration of growing radicals during the polymerization with this initiation system. End group analysis by H-1-NMR spectroscopic studies showed that the end groups of the polymer obtained is omega -functionalized by a chlorine group from the catalyst and alpha -functionalized by a (carbethoxy-cyano-phenyl)methyl group from the fragments of the initiator. Having CI atom at the chain end, the PSt obtained can be used as a macroinitiator to promote a chain-extension reaction with fresh St and block copolymerization reaction with a second monomer, such as methyl methacrylate, in the presence of CuCl/bipy catalyst via a conventional ATRP process.展开更多
Polystyrene macromonomers with different molecular weight were prepared by radical polymerization of styrene(St) in benzene using β-methacryloxylethyl 2-N,N-diethyldithiocarbamylacetate (MAEDCA) as a monomer-iniferte...Polystyrene macromonomers with different molecular weight were prepared by radical polymerization of styrene(St) in benzene using β-methacryloxylethyl 2-N,N-diethyldithiocarbamylacetate (MAEDCA) as a monomer-iniferter.Characterization of the macromonomer by ~1H-NMR showed that the end groups were α-methacrylyoxylethyloxycarbonyl-methyl and ω-(N,N-diethyldithiocarbamyl). The macromonomer was difficult to homopolymerize, but it was easilycopolymerized with methyl methacrylate (MMA) initiated by AIBN to form graft copolymers (PMMA-g-PSt) with PStbranches randomly distributed along the PMMA backbone. Copolymerization reaction and the structure of the graft copolymers were strongly affected by M_n and concentration of the macromonomer. The composition and M_n of the purified graft copolymer were determined by ~1H-NMR and GPC analysis.展开更多
ABA triblock copolymers containing polyisoprene segments,such as polyisoprene b polystyrene b polyisoprene (PIP b PSt b PIP)and polyisoprene b poly(methyl methacrylate) b polyisoprene(PIP b PMMA b PIP),were prepared w...ABA triblock copolymers containing polyisoprene segments,such as polyisoprene b polystyrene b polyisoprene (PIP b PSt b PIP)and polyisoprene b poly(methyl methacrylate) b polyisoprene(PIP b PMMA b PIP),were prepared with macro iniferter technique.The macro iniferters (PSt CCDCM and PMMA CCDCM)bearing α and ω N,N diethyldithiocarbamyl (DC)groups were synthesized by bulk polymerization of St and MMA with diethyl 2,3 dicyano 2,3 di( p N,N diethyldithiocarbamylmethyl) phenylsuccinate (DDDCS) as a thermal iniferter.The block copolymerization of IP with PSt CCDCM or PMMA CCDCM was carried out under UV light irradiation.The block copolymers were characterized by 1H NMR,GPC and DSC analyses,and the polymerization proceeded as a living polymerization process.展开更多
基金Acknowledgments： The work was supported by the National Nature Science Foundation of China （No. 20574050）, the Science and Technology Development Planning of Jiangsu Province （No. BK2007702 and BK2007048）, and the Nature Science Key Basic Research of Jiangsu Province for Higher Education （No. 05KJA15008）.
文摘Atom transfer radical polymerizations （ATRPs） of styrene （St） in bulk initiated by six iniferter reagents were carried out, respectively, in the present of copper （1） bromide （CuBr） and N, N,N＇,N＂,N＂-pentamethyldiethylenetriamine （PMDETA） at 115℃. All the kinetic plots were first-order with respect to the monomer concentrations. At the same time, the corresponding molecular weights of the polymers increased linearly with the respective monomer conversions. Furthermore, the molecular weight distributions remained relatively narrow （Mw/Mn〈1.50） in all cases. Solution ATRP of St in dimethyl- formamide （DMF） initiated by benzyl N, N-diethyldithiocarba- mate （BDC） also showed the characteristics of living radical polymerization. The results of 1H NMR analysis and chain extension experiment confirmed that the well-defined polystyrene （PS） bearing photo-liable group has been obtained via ATRP of St using photoiniferter reagents as the initiators.
文摘The polymerization behaviors of Styrene (St) in the presence of CuX/L [X=Cl or Br; L= 2,2 bipyridine (bpy), 1,10 phenanthroline (phen) or 4,7 diphenyl 1,10 phenanthroline (DPP) ] and R X (R=trichloromethyl, benzyl or allyl; X=Cl or Br) have been studied and examined. In a CuCl/bpy/RCl/St system, a bimodal GPC peak at the early stage of polymerization was observed, and a concept of multi active species was proposed to explain this phenomenon. In a CuCl/phen (DPP)/RCl/St system, the \%M\%\-n of polystyrene (PS) increased linearly with St conversion and ln[M] o/[M] also increased linearly with time, indicating the living nature of this system. Furthermore, the stability of the propagating active species in a CuBr/phen/RBr/St system is higher than that in the CuBr/phen/RBr/St system.
文摘'Living'/controlled radical polymerization of styrene was carried out with diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS)/CuCl2/bipyridine (bipy) initiation system at 120 degreesC. The molecular weights of resultant PSt increased with the monomer conversion and the polydispersities were in the range of 1.37 similar to1.52. A linear ln([M](o)/[M]) versus time plot was also obtained indicating the constant concentration of growing radicals during the polymerization with this initiation system. End group analysis by H-1-NMR spectroscopic studies showed that the end groups of the polymer obtained is omega -functionalized by a chlorine group from the catalyst and alpha -functionalized by a (carbethoxy-cyano-phenyl)methyl group from the fragments of the initiator. Having CI atom at the chain end, the PSt obtained can be used as a macroinitiator to promote a chain-extension reaction with fresh St and block copolymerization reaction with a second monomer, such as methyl methacrylate, in the presence of CuCl/bipy catalyst via a conventional ATRP process.
文摘Polystyrene macromonomers with different molecular weight were prepared by radical polymerization of styrene(St) in benzene using β-methacryloxylethyl 2-N,N-diethyldithiocarbamylacetate (MAEDCA) as a monomer-iniferter.Characterization of the macromonomer by ~1H-NMR showed that the end groups were α-methacrylyoxylethyloxycarbonyl-methyl and ω-(N,N-diethyldithiocarbamyl). The macromonomer was difficult to homopolymerize, but it was easilycopolymerized with methyl methacrylate (MMA) initiated by AIBN to form graft copolymers (PMMA-g-PSt) with PStbranches randomly distributed along the PMMA backbone. Copolymerization reaction and the structure of the graft copolymers were strongly affected by M_n and concentration of the macromonomer. The composition and M_n of the purified graft copolymer were determined by ~1H-NMR and GPC analysis.
文摘ABA triblock copolymers containing polyisoprene segments,such as polyisoprene b polystyrene b polyisoprene (PIP b PSt b PIP)and polyisoprene b poly(methyl methacrylate) b polyisoprene(PIP b PMMA b PIP),were prepared with macro iniferter technique.The macro iniferters (PSt CCDCM and PMMA CCDCM)bearing α and ω N,N diethyldithiocarbamyl (DC)groups were synthesized by bulk polymerization of St and MMA with diethyl 2,3 dicyano 2,3 di( p N,N diethyldithiocarbamylmethyl) phenylsuccinate (DDDCS) as a thermal iniferter.The block copolymerization of IP with PSt CCDCM or PMMA CCDCM was carried out under UV light irradiation.The block copolymers were characterized by 1H NMR,GPC and DSC analyses,and the polymerization proceeded as a living polymerization process.
