On the basis of research method in FTIR imaging, we made a heterogeneous thin film of isotactic polypropylene （iPP） that contains a few large spherulites （-150 μm） which are surrounded by small spherulites （-15 ...On the basis of research method in FTIR imaging, we made a heterogeneous thin film of isotactic polypropylene （iPP） that contains a few large spherulites （-150 μm） which are surrounded by small spherulites （-15 μm） for tensile testing. The evolution processes of crystalline and amorphous orientations of iPP are monitored with its characteristic peaks at 998 and 973 cm^-1, respectively. By introducing the correlation images, the analysis demonstrates the relationships between the orientation evolutions of crystalline and amorphous phases in a space of 250 μm × 250 μm detecting area. During the plastic deformation, crystalline orientation is higher than amorphous orientation outside the large spherulite, while that is opposite inside the region. In addition, the evolutions of crystalline and amorphous orientations almost keep a positive correlation.展开更多
Herein, we demonstrate the synthesis of a well-defined diblock copolymer consisting of isotactic polystyrene （iPS） and linear polyethylene, isotactic polystyrene-block-polyethylene （iPS-b-PE）, by the combination o...Herein, we demonstrate the synthesis of a well-defined diblock copolymer consisting of isotactic polystyrene （iPS） and linear polyethylene, isotactic polystyrene-block-polyethylene （iPS-b-PE）, by the combination of sequential monomer addition and hydrogenation. Isospecific living polymerization of styrene and living trans-1,4-polymerization of 1,3-butadiene were catalyzed by 1,4-dithiabutandiyl-2,2＇-bis（6-cumenyl-4-methylphenoxy） titanium dichloride （complex 1） activated by triisobutyl aluminum modified methylaluminoxane （MMAO） at room tempera^xre to provide highly isotactic polystyrene （iPS） and 1,4-trans-polybutadiene （1,4-trans-PBD） with narrow molecular weight distribution. Furthermore, the iPS-b-I,4- trans-PBD was synthesized via sequential monomer addition in the presence of complex 1 and MMAO. The hydrogenation of the 1,4-trans-PBD block was promoted by RuC12（PPh3）3 used as a catalyst to produce iPS-b-PE.展开更多
基金financially supported by the China Postdoctoral Science Foundation(No.2012M521233)the Fundamental Research Funds for the Central Universities(No.WK2310000031)+1 种基金the National Natural Science Funds for Distinguished Young Scholar(No.51325301)973 program of MOST(No.2010CB934504)
文摘On the basis of research method in FTIR imaging, we made a heterogeneous thin film of isotactic polypropylene （iPP） that contains a few large spherulites （-150 μm） which are surrounded by small spherulites （-15 μm） for tensile testing. The evolution processes of crystalline and amorphous orientations of iPP are monitored with its characteristic peaks at 998 and 973 cm^-1, respectively. By introducing the correlation images, the analysis demonstrates the relationships between the orientation evolutions of crystalline and amorphous phases in a space of 250 μm × 250 μm detecting area. During the plastic deformation, crystalline orientation is higher than amorphous orientation outside the large spherulite, while that is opposite inside the region. In addition, the evolutions of crystalline and amorphous orientations almost keep a positive correlation.
基金supported by the National Natural Science Foundation of China(Nos.21174167 and51573212)the Natural Science Foundation of Guangdong Province(Nos.S2013030013474 and 2014A030313178)
文摘Herein, we demonstrate the synthesis of a well-defined diblock copolymer consisting of isotactic polystyrene （iPS） and linear polyethylene, isotactic polystyrene-block-polyethylene （iPS-b-PE）, by the combination of sequential monomer addition and hydrogenation. Isospecific living polymerization of styrene and living trans-1,4-polymerization of 1,3-butadiene were catalyzed by 1,4-dithiabutandiyl-2,2＇-bis（6-cumenyl-4-methylphenoxy） titanium dichloride （complex 1） activated by triisobutyl aluminum modified methylaluminoxane （MMAO） at room tempera^xre to provide highly isotactic polystyrene （iPS） and 1,4-trans-polybutadiene （1,4-trans-PBD） with narrow molecular weight distribution. Furthermore, the iPS-b-I,4- trans-PBD was synthesized via sequential monomer addition in the presence of complex 1 and MMAO. The hydrogenation of the 1,4-trans-PBD block was promoted by RuC12（PPh3）3 used as a catalyst to produce iPS-b-PE.
