: Copolymers used for transparent fibre glass-reinforced thermoplastic composite -were prepared from methyl methacrylate (.MMA) and styrene (St). Composites containing 20~25 ivt% glass fibre and 0. 7 mm in thickness h...: Copolymers used for transparent fibre glass-reinforced thermoplastic composite -were prepared from methyl methacrylate (.MMA) and styrene (St). Composites containing 20~25 ivt% glass fibre and 0. 7 mm in thickness had an overall optical transmission of 88 ~90%. The gel time and cure time of the prepolymers from MM A and St decreased markedly ivith addition of tiie two linear unsaturated polyesters (.LUPE) and curing process of composite laminate became controlling easily-The effect of the concentration of LUPE on thermal stability of copolymers 晅he optical properties and the hydrothermal sta-bility of composites was investigated by comparing with those of trans-parent unsaturated composites .展开更多
Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the...Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the shape and size of the self-assembled morphologies, and hence, a high degree of control over the self-assembly is desired. Grafting block copolymer chains onto a substrate to form copolymer brushes is a versatile method to fabricate functional surfaces. Such surfaces demonstrate a response to their environment, i.e., they change their surface topography in response to different external conditions. Furthermore, such surfaces may possess nanoscale patterns, which are important for some applica- tions; however, such patterns may not form with spun-cast films under the same condition. In this review, we summarize the recent progress of the self-assembly of block copolymers grafted onto a flat substrate. We mainly concentrate on the self-assembled morphologies of end-grafted AB dibloek eopolymers, junction p0int-grafted AB diblock copolymers （i.e., Y-shaped brushes）, and end-grafted ABA triblock copolymers. Special emphasis is placed on theoretical and simulation progress.展开更多
The catalyst {[(2-ArN=C(Me))2C5H3N]FeCl3} (Ar = 2-C6H4(i-Pr)) with methylaluminoxane (MAO) as co-catalyst was intercalated between layers of montmorillonite (MMT) for ethylene oligomerization. Metallocene catalyst Me2...The catalyst {[(2-ArN=C(Me))2C5H3N]FeCl3} (Ar = 2-C6H4(i-Pr)) with methylaluminoxane (MAO) as co-catalyst was intercalated between layers of montmorillonite (MMT) for ethylene oligomerization. Metallocene catalyst Me2Si(Ind)2ZrCl2 and MAO was then added to form a dual functional catalytic system. A PE/MMT nanocomposite was prepared by copolymerization of ethylene with α-olefins produced in situ from ethylene over the dual functional catalytic system. The catalytic system was of high polymeric activity. The resultant PE/MMT nanocomposites were stable and got increases in tensile strength and temperature of maximum weight loss (Tonset).展开更多
文摘: Copolymers used for transparent fibre glass-reinforced thermoplastic composite -were prepared from methyl methacrylate (.MMA) and styrene (St). Composites containing 20~25 ivt% glass fibre and 0. 7 mm in thickness had an overall optical transmission of 88 ~90%. The gel time and cure time of the prepolymers from MM A and St decreased markedly ivith addition of tiie two linear unsaturated polyesters (.LUPE) and curing process of composite laminate became controlling easily-The effect of the concentration of LUPE on thermal stability of copolymers 晅he optical properties and the hydrothermal sta-bility of composites was investigated by comparing with those of trans-parent unsaturated composites .
基金supported by the National Natural Science Foundation of China(Grant Nos.20990234,20925414,and 91227121)the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT1257)+1 种基金the Programme of Introducing Talents of Discipline to Universities,Chinaby the Tianhe No.1,China
文摘Block copolymers are a class of soft matter that self-assemble to form ordered morphologies on the scale of nanome- ters, making them ideal materials for various applications. These applications directly depend on the shape and size of the self-assembled morphologies, and hence, a high degree of control over the self-assembly is desired. Grafting block copolymer chains onto a substrate to form copolymer brushes is a versatile method to fabricate functional surfaces. Such surfaces demonstrate a response to their environment, i.e., they change their surface topography in response to different external conditions. Furthermore, such surfaces may possess nanoscale patterns, which are important for some applica- tions; however, such patterns may not form with spun-cast films under the same condition. In this review, we summarize the recent progress of the self-assembly of block copolymers grafted onto a flat substrate. We mainly concentrate on the self-assembled morphologies of end-grafted AB dibloek eopolymers, junction p0int-grafted AB diblock copolymers （i.e., Y-shaped brushes）, and end-grafted ABA triblock copolymers. Special emphasis is placed on theoretical and simulation progress.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 29734141 and 50103012).
文摘The catalyst {[(2-ArN=C(Me))2C5H3N]FeCl3} (Ar = 2-C6H4(i-Pr)) with methylaluminoxane (MAO) as co-catalyst was intercalated between layers of montmorillonite (MMT) for ethylene oligomerization. Metallocene catalyst Me2Si(Ind)2ZrCl2 and MAO was then added to form a dual functional catalytic system. A PE/MMT nanocomposite was prepared by copolymerization of ethylene with α-olefins produced in situ from ethylene over the dual functional catalytic system. The catalytic system was of high polymeric activity. The resultant PE/MMT nanocomposites were stable and got increases in tensile strength and temperature of maximum weight loss (Tonset).
