Six samples of linear high randomness 60PHB/ PET thermotropic liquid crystal copolyesters are made by melt copolymerization at 290℃ , whose randomness about 0.955 is measured by the discernible ’H-NMR spectrometer. ...Six samples of linear high randomness 60PHB/ PET thermotropic liquid crystal copolyesters are made by melt copolymerization at 290℃ , whose randomness about 0.955 is measured by the discernible ’H-NMR spectrometer. High tenacity, high module fiber is prepared by melt spinning in liquid crystal phase. The effect of molecular weight, shear rate, temperature as well as spinning drawn ratio on the mechanical behavior of 60PHB / PET copolyester fiber are shown that, lower shear rate (2<sup> </sup>10 s<sup>-1</sup>), higher temperature melting （300℃ ）, lower temperature spinning （280℃ ） and higher molecular weight are favourable to the increase of the fiber mechanical properties. With the variance of drawn ratio, fiber mechanical property has a transition point due to traversion from shear-orientation to drawn-orientation. The copolyester fiber has high crystallinity, high orientation at the crystalline region, high chain orientation and high regular fibrillar structure.展开更多
Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Comp...Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Compared to the original nano-ZrO2,the grafted nano-ZrO2 had better compatibility with the polycarbonate(PC) matrix and could be dispersed more homogeneously in PC.Hence,interfacial adhesion between ZrO2 and PC was enhanced.The mechanical properties of the resultant PC/nano-ZrO2 composite like tensile strength and notched impact strength were greatly improved.Calculated respectively from tensile yield stress PC/nano-ZrO2 composites,the interfacial interaction parameter B was employed to quantitatively characterize the effective interfacial interaction between the nano-ZrO2 and PC matrix.展开更多
文摘Six samples of linear high randomness 60PHB/ PET thermotropic liquid crystal copolyesters are made by melt copolymerization at 290℃ , whose randomness about 0.955 is measured by the discernible ’H-NMR spectrometer. High tenacity, high module fiber is prepared by melt spinning in liquid crystal phase. The effect of molecular weight, shear rate, temperature as well as spinning drawn ratio on the mechanical behavior of 60PHB / PET copolyester fiber are shown that, lower shear rate (2<sup> </sup>10 s<sup>-1</sup>), higher temperature melting （300℃ ）, lower temperature spinning （280℃ ） and higher molecular weight are favourable to the increase of the fiber mechanical properties. With the variance of drawn ratio, fiber mechanical property has a transition point due to traversion from shear-orientation to drawn-orientation. The copolyester fiber has high crystallinity, high orientation at the crystalline region, high chain orientation and high regular fibrillar structure.
基金Innovative Team Project of Science and Technology Commission of Shanghai, China(No.06DZ05902)
文摘Nano-ZrO2 particles were modified by poly(ethylene terephalate) prepolymer(pre-PET) via polycondensation.FT-IR,TEM,and TGA results showed that pre-PET was successfully grafted on the surface of nano-ZrO2particles.Compared to the original nano-ZrO2,the grafted nano-ZrO2 had better compatibility with the polycarbonate(PC) matrix and could be dispersed more homogeneously in PC.Hence,interfacial adhesion between ZrO2 and PC was enhanced.The mechanical properties of the resultant PC/nano-ZrO2 composite like tensile strength and notched impact strength were greatly improved.Calculated respectively from tensile yield stress PC/nano-ZrO2 composites,the interfacial interaction parameter B was employed to quantitatively characterize the effective interfacial interaction between the nano-ZrO2 and PC matrix.
