Nanocomposites were obtained by mixing elastomeric copolymer and nanoSiO2 in double-screw extruder at 130-150°C, in which the elastomeric copolymer was prepared by copolymerization of poly (methyl methacrylate (PMMA) macromonomer and butyl acrylate (BA) in benzene using azobisisobutyro-nitrile (AIBN) as initiator. The results indicated that increasing the amount of PMMA, the molecular weight of PMMA and copolymers, nanosilica charged resulted in improving the tensile strength and modulus at 300% elongation of nanocomposites, on the contrary, decreasing ultimate elongation and permanent set decrease. In additions, the tensile strength and the modulus at 300% elongation of nanocomposites reached to a maximum while the mass ratio of nanoSiO2 to copolymer was 3%.
In order to reveal the effect of drying temperature on quality of purple sweet potato powder, four drying temperatures (70, 80, 90 and 100 oC) were selected. The effect of color, anthocyanin content, and scavenging ABTS free radical ability were studied. The results showed that drying process decreased anthocyanin content, and with increasing drying temperature, the a* value and anthocyanin content decreased. However, the treatments dried at 80, 90 oC exhibited the similar scavenging ABTS free radical ability with control, while the treatments dried at 70, 100 oC had lower scavenging ability than control.
The influences of ZnEt2 on ethylene chain transfer polymerization were investigated in detail and the polymerization mechanism was thoroughly analyzed. The results indicated that ZnEt2 contributed greatly to increase the activity of α-diimine nickel complex/ZnEt2/MAO(MAO: methylaluminoxane). It was striking that α-diimine nickel complex/ZnEt2 catalyst system (1/100 mol/mol) exhibited 8.0 ×104g/mol∙h activity, it was possible the formation of the ion pairs of Nickel and Zinc was convenient for ethylene chain propagation, however, the ion pairs were unstable in ethylene polymerization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.