A simulation study was carried out by using dissipative particle dynamics(DPD) method to explore the effects of properties of coating chains, such as length, density, rigidity of polymer chains, as well as the distanc...A simulation study was carried out by using dissipative particle dynamics(DPD) method to explore the effects of properties of coating chains, such as length, density, rigidity of polymer chains, as well as the distance between nanoparticles on bonding reaction of coating chains grafted onto nanoparticles. The results show that bonding ratios of coated chains strongly depend on the length and density of coating chains. For nanoparticles with different coating densities, the optimum chain length for bonding reaction are varied. The rigidity of coating chains exhibits vigorous effects on bonding reaction that highly depends on chain lengths. DPD simulation can be used to study the bonding reaction between coated nanoparticles, which may help experimental synthesis of nanocomposites with excellent properties.展开更多
Diblock copolymers polystyrene-block-polyvinyltriethoxysilane（PS-b-PVTES） were synthesized via atom transfer radical polymerization（ATRP）, which self-assembled into spherical micelles in solvent of THF-methanol mi...Diblock copolymers polystyrene-block-polyvinyltriethoxysilane（PS-b-PVTES） were synthesized via atom transfer radical polymerization（ATRP）, which self-assembled into spherical micelles in solvent of THF-methanol mixtures. The self-assembled micelles were immobilized by cross-linking reaction of VTES in a shell layer of micelles. The chemical structures of block copolymers and morphology of micelles were characterized in detail. It was found that the size of immobilized micelles was strongly affected by the copolymer concentration, composition of mixture solvent, and block ratios.展开更多
Thin films of polymer blends composed of alternating copolymer, diblock copolymer and/or homopolymer are studied using Monte Carlo simulation. A multilayer morphology is observed in the film, that is, the blended poly...Thin films of polymer blends composed of alternating copolymer, diblock copolymer and/or homopolymer are studied using Monte Carlo simulation. A multilayer morphology is observed in the film, that is, the blended polymers assemble into individual domains arranged from interior to the surfaces of the film. The coexisting components residing throughout the neighboring domains in the film make no distinguishable interface between any neighboring domains. By this means, it forms a vertical composition gradient in the polymeric film. Being different from layer-by-layer deposition of polyelectrolyte or hydrogen bonding approach etc., the layered structure in this study is formed by polymer blending in one step. Alternating copolymers are found to be essential components to form vertical composition gradient （layered structure） in thin films.展开更多
The foamed polypropylene（PP） with excellent mechanical and thermal insulating properties was reinforced by blending chlorinated polyethylene（CPE）, followed by compression molding foaming in cross-link. The effects...The foamed polypropylene（PP） with excellent mechanical and thermal insulating properties was reinforced by blending chlorinated polyethylene（CPE）, followed by compression molding foaming in cross-link. The effects of CPE on the foaming behavior, thermal and mechanical properties of the foamed PP were studied by the measurements of density, thermal conductivity, Vicat softening temperature, tensile strength, impact strength and SEM. The results showed that the foamed PP got the best properties when the weight ratio of CPE/PP was 20 wt%. The density of the obtained foamed PP was as low as 0.37 g/cm^3, the impact strength was 16.5 kJ/m^2, the tensile strength was 17.7 MPa, the thermal conductivity was 0.035 W/（m·K）, and the Vicat softening temperature was 112 ℃.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.20974001,21174001,51273001,and 51403001)
文摘A simulation study was carried out by using dissipative particle dynamics(DPD) method to explore the effects of properties of coating chains, such as length, density, rigidity of polymer chains, as well as the distance between nanoparticles on bonding reaction of coating chains grafted onto nanoparticles. The results show that bonding ratios of coated chains strongly depend on the length and density of coating chains. For nanoparticles with different coating densities, the optimum chain length for bonding reaction are varied. The rigidity of coating chains exhibits vigorous effects on bonding reaction that highly depends on chain lengths. DPD simulation can be used to study the bonding reaction between coated nanoparticles, which may help experimental synthesis of nanocomposites with excellent properties.
基金Funded by the National Natural Science Foundation of China(Nos.51403001,20804001,20974001,21174001,51273001)the Research Fund for the Doctoral Program of Higher Education of China(No.20113401110003)"211 Project"and"Incubation Fund for Excellent Young Researcher"of Anhui University
文摘Diblock copolymers polystyrene-block-polyvinyltriethoxysilane（PS-b-PVTES） were synthesized via atom transfer radical polymerization（ATRP）, which self-assembled into spherical micelles in solvent of THF-methanol mixtures. The self-assembled micelles were immobilized by cross-linking reaction of VTES in a shell layer of micelles. The chemical structures of block copolymers and morphology of micelles were characterized in detail. It was found that the size of immobilized micelles was strongly affected by the copolymer concentration, composition of mixture solvent, and block ratios.
基金financially supported by the National Natural Science Foundation of China(Nos.20804001,20974001,21174001 and 51273001)the Research Fund for the Doctoral Program of Higher Education of China(20113401110003)+2 种基金the University Natural Science Research Project of Anhui Province(KJ2011z015)"211 Project""Incubation Fund for Excellent Young Researcher" of Anhui University
文摘Thin films of polymer blends composed of alternating copolymer, diblock copolymer and/or homopolymer are studied using Monte Carlo simulation. A multilayer morphology is observed in the film, that is, the blended polymers assemble into individual domains arranged from interior to the surfaces of the film. The coexisting components residing throughout the neighboring domains in the film make no distinguishable interface between any neighboring domains. By this means, it forms a vertical composition gradient in the polymeric film. Being different from layer-by-layer deposition of polyelectrolyte or hydrogen bonding approach etc., the layered structure in this study is formed by polymer blending in one step. Alternating copolymers are found to be essential components to form vertical composition gradient （layered structure） in thin films.
基金Funded by the National Natural Science Foundation of China(No.51403001)the Key Laboratory of Renewable Energy,Chinese Academy of Sciences(No.y407k31001)the Anhui Provincial Department of Education(No.2013KJS030018)
文摘The foamed polypropylene（PP） with excellent mechanical and thermal insulating properties was reinforced by blending chlorinated polyethylene（CPE）, followed by compression molding foaming in cross-link. The effects of CPE on the foaming behavior, thermal and mechanical properties of the foamed PP were studied by the measurements of density, thermal conductivity, Vicat softening temperature, tensile strength, impact strength and SEM. The results showed that the foamed PP got the best properties when the weight ratio of CPE/PP was 20 wt%. The density of the obtained foamed PP was as low as 0.37 g/cm^3, the impact strength was 16.5 kJ/m^2, the tensile strength was 17.7 MPa, the thermal conductivity was 0.035 W/（m·K）, and the Vicat softening temperature was 112 ℃.
