On the basis of population balance a mathematical model is developed to describe the formation of polymer particle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and ...On the basis of population balance a mathematical model is developed to describe the formation of polymer particle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and the gel effect are analyzed in particular. Parameters of the models are estimated by experimental data on reaction conversion and particle size distribution. The results show that the model is suitable for predicting polymerization processes.展开更多
A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temp...A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temperature and pressure range.Combined with a modified Huron-Vidal gE-mixing rule it was applied for modeling vapor-liquid equilibria of polymer-solvent solutions and the solubility of supercritical gases in polymer melts.Satisfactory results are obtained.展开更多
Based on three typical mechanisms (second-order, third-order and competitive mechanisms) for the curing reactions of the epoxy resins with amines, a pair of the kinetic equations (for primary and secondary aminations)...Based on three typical mechanisms (second-order, third-order and competitive mechanisms) for the curing reactions of the epoxy resins with amines, a pair of the kinetic equations (for primary and secondary aminations) was presented to explain the uniformity and relationship among the three different kinetic mechanisms of the reactions. The presented macro-equations were deduced from the kinetic micro-equations by the statistics method. And the constitutive equations were verified by experimental data at different reaction times and temperatures (95°C, 60°C and 39°C), taking diglycidyl ether of bisphenol A (DGEBA) /ethyleneamine (EA) as a model.展开更多
The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new ac...The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new activity coefficient equation, which can be satisfactorily applied to polymer solutions, is obtained. The calculated results for the VLE of 179 polymer solutions show that the accuracy of fit is evidently superior to UNIQUAC equation.展开更多
Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and...Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and IIG） into a polymer main chain to form A-A＇ polymer PIIG-BTz could lower highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm2 V 1 s-i was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor （A-A＇） structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors.展开更多
文摘On the basis of population balance a mathematical model is developed to describe the formation of polymer particle in styrene suspension polymerization. The characteristics of coalescence and breakage of droplets and the gel effect are analyzed in particular. Parameters of the models are estimated by experimental data on reaction conversion and particle size distribution. The results show that the model is suitable for predicting polymerization processes.
基金Supported by the Zhejiang Provincial Foundation for Returned Scholarsthe Scientific Research Foundation of the State Human Resource Ministry.
文摘A simple extension of cubic equations of state(EOS)to polymer systems has been proposed.The So-ave-Redlich-Kwong(SRK)EOS was taken as a prototype to be used to describe the PVT behavior of polymer melts in a wide temperature and pressure range.Combined with a modified Huron-Vidal gE-mixing rule it was applied for modeling vapor-liquid equilibria of polymer-solvent solutions and the solubility of supercritical gases in polymer melts.Satisfactory results are obtained.
文摘Based on three typical mechanisms (second-order, third-order and competitive mechanisms) for the curing reactions of the epoxy resins with amines, a pair of the kinetic equations (for primary and secondary aminations) was presented to explain the uniformity and relationship among the three different kinetic mechanisms of the reactions. The presented macro-equations were deduced from the kinetic micro-equations by the statistics method. And the constitutive equations were verified by experimental data at different reaction times and temperatures (95°C, 60°C and 39°C), taking diglycidyl ether of bisphenol A (DGEBA) /ethyleneamine (EA) as a model.
基金Supported by the National Natural Science Foundation of China(No.29376236).
文摘The original van Laar's theory has been modified. The internal pressures of components and mixture are expressed by Frank's relation and the excess entropy for mixing of components is also considered. A new activity coefficient equation, which can be satisfactorily applied to polymer solutions, is obtained. The calculated results for the VLE of 179 polymer solutions show that the accuracy of fit is evidently superior to UNIQUAC equation.
基金supported by the National Natural Science Foundation of China (51173055, 21504026, 51572094)the National Basic Research Program of China (2013CBA01600)the China Postdoctoral Science Foundation (2013M542009)
文摘Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and IIG） into a polymer main chain to form A-A＇ polymer PIIG-BTz could lower highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm2 V 1 s-i was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor （A-A＇） structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors.
