A mathematical model for extraction of red pepper seed oil with supercritical CO2was proposed.Some factors influencing the process were investigated,including operation pressure,temperature and extraction yield Xe(%)....A mathematical model for extraction of red pepper seed oil with supercritical CO2was proposed.Some factors influencing the process were investigated,including operation pressure,temperature and extraction yield Xe(%).The model was solved by the method of weighted residuals and used to simulate the process numerically.The kinetic equation is expressed as Xe16.8606exp(t/9.98177)16.95457 and the simulation results are in excellent agreement with the experimental data.The optimal operating parameters are 30 MPa,318 K and 60 min.展开更多
Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesteri...Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesterification reaction. The effects of the crystallization conditions on melting behavior and SSP of BPA-PC were investigated with differential scanning calorimetry （DSC）, Ubbelohde viscosity method and gel permeation chromatography （GPC）. The reaction kinetics of the SSP of crystallized prepolymers was studied as a function of reaction temperatures for various reaction periods. As a result, the viscosity average molecular weight of BPA-PC particles （2 mm） increased from 1.9 × 10^4 g/mol to 2.8 × 10^4 g/mol after SSP. More importantly, the significantly enhanced thermal stability and mechanical properties of solid-state polymerized BPA-PC, compared with those of melt transesterification polymerized BPA-PC with the same molecular weight, can be ascribed to the substantial avoidance of undergoing high temperature during polymerization. Our work provides a useful method to obtain practical product of BPA-PC with high quality and high molecular weight.展开更多
基金Supported by the Opening Foundation of Key Laboratory of Resource Biology and Biotechnology in Western China(ZS12015)the Ministry of Education and Natural Science Foundation of Education Committee of Shaanxi Province(11JK0598)the 2012 Xi’an Modern Agricultural Promotion Project(NC1207)
文摘A mathematical model for extraction of red pepper seed oil with supercritical CO2was proposed.Some factors influencing the process were investigated,including operation pressure,temperature and extraction yield Xe(%).The model was solved by the method of weighted residuals and used to simulate the process numerically.The kinetic equation is expressed as Xe16.8606exp(t/9.98177)16.95457 and the simulation results are in excellent agreement with the experimental data.The optimal operating parameters are 30 MPa,318 K and 60 min.
基金financially supported by the National Natural Science Foundation of China(No.51173112)
文摘Poly（bisphenol A carbonate） （BPA-PC） was post-polymerized by solid-state polymerization （SSP） after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesterification reaction. The effects of the crystallization conditions on melting behavior and SSP of BPA-PC were investigated with differential scanning calorimetry （DSC）, Ubbelohde viscosity method and gel permeation chromatography （GPC）. The reaction kinetics of the SSP of crystallized prepolymers was studied as a function of reaction temperatures for various reaction periods. As a result, the viscosity average molecular weight of BPA-PC particles （2 mm） increased from 1.9 × 10^4 g/mol to 2.8 × 10^4 g/mol after SSP. More importantly, the significantly enhanced thermal stability and mechanical properties of solid-state polymerized BPA-PC, compared with those of melt transesterification polymerized BPA-PC with the same molecular weight, can be ascribed to the substantial avoidance of undergoing high temperature during polymerization. Our work provides a useful method to obtain practical product of BPA-PC with high quality and high molecular weight.
