Nano-ZnO particle （nZnOp） reinforced polyethylene glycol （PEG）/polyethylene terephthalate （PET） （nZnOp/PEG/PET） copolymeric composites with different mass fractions and molecular weights of PEG are synthesized...Nano-ZnO particle （nZnOp） reinforced polyethylene glycol （PEG）/polyethylene terephthalate （PET） （nZnOp/PEG/PET） copolymeric composites with different mass fractions and molecular weights of PEG are synthesized via in-situ polymerization. The dispersion of nZnOp in copolymer matrixes and the effects of PEG and nZnOp particles on the crystallization behavior of the composites are studied by TEM, differential scanning calorimetry（DSC）, XRD and Fourier thansform infrared spectroscopy （FTIR ）. The results reveal that nZnOp particles are dispersed in the matrixes with nano-scale, and the addition of PEG induces more homogeneous dispersion of nZnOp. Simultaneously, these nanoparticles become nucleating centers during the crystallization of the matrixes. PEG segments can improve the flexibility of the PET molecular chain, resulting in the drop of the cold crystallization temperature and the rise of the crystallization rate of the composites. Furthermore, PEG （4 000） with the mass fraction of 10% can promote the crystallization rate of the composites. The mechanical properties show that the nano-particles strengthen and toughen the PET matrix, whereas PEG weakens these improve- ments.展开更多
Dimethyl carbonate （DMC） and poly（ethylene terephthalate） was simultaneously synthesized by the transesterification of ethylene carbonate （EC） with dimethyl terephthalate （DMT） in this paper. This reaction is ...Dimethyl carbonate （DMC） and poly（ethylene terephthalate） was simultaneously synthesized by the transesterification of ethylene carbonate （EC） with dimethyl terephthalate （DMT） in this paper. This reaction is an excellent green chemical process without poisonous substance. Various alkali metals were used as the catalysts. The results showed alkali metals had catalytic activity in a certain extent. The effect of reaction condition was also studied. When the reaction was carded out under the following conditions： the reaction temperature 250℃, molar ratio of EC to DMT 3 ： 1, reaction time 3h, and catalyst amount 0.004 （molar ratio to DMT）, the yield of DMC was 68.9%.展开更多
Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials ...Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.展开更多
The effects of different treatments, such as dry heat,wet heat, solvent vapor and ultrasonic, on propertiesof the cyclic oligomers on the surface of polyester fiberare studied. The components of surface oligomers area...The effects of different treatments, such as dry heat,wet heat, solvent vapor and ultrasonic, on propertiesof the cyclic oligomers on the surface of polyester fiberare studied. The components of surface oligomers areanalyzed through Thin-Layer Chromatograph. Theresult shows that: all of the treatment, especially solvent vapor treatment,call significantly increase the content of surface cyclic oligomers.The content of cyclic triIner is increased more considerably than other oligomers. Moreover,the morphology and thedistribution of surface cyclic oligomers are also different from different treatments:Dry heat and wet heat cause larger polygonal solids distributed evenly on the surface of fiber;solvent vapor nlakes fiber surface exhibit irregular rodlike crystal shapes randomly;ultrasonic treatment induces some obscureand smaller deposi^on the surface of fiber.展开更多
基金Supported by the Program of Jiangsu Development & Reform Commission(2005)the Industrial-ization Boosting Program of College Scientific Reserach Achievements of the Education Department of Jiangsu Province(JHB06-03)~~
文摘Nano-ZnO particle （nZnOp） reinforced polyethylene glycol （PEG）/polyethylene terephthalate （PET） （nZnOp/PEG/PET） copolymeric composites with different mass fractions and molecular weights of PEG are synthesized via in-situ polymerization. The dispersion of nZnOp in copolymer matrixes and the effects of PEG and nZnOp particles on the crystallization behavior of the composites are studied by TEM, differential scanning calorimetry（DSC）, XRD and Fourier thansform infrared spectroscopy （FTIR ）. The results reveal that nZnOp particles are dispersed in the matrixes with nano-scale, and the addition of PEG induces more homogeneous dispersion of nZnOp. Simultaneously, these nanoparticles become nucleating centers during the crystallization of the matrixes. PEG segments can improve the flexibility of the PET molecular chain, resulting in the drop of the cold crystallization temperature and the rise of the crystallization rate of the composites. Furthermore, PEG （4 000） with the mass fraction of 10% can promote the crystallization rate of the composites. The mechanical properties show that the nano-particles strengthen and toughen the PET matrix, whereas PEG weakens these improve- ments.
基金the National High Technology Research and Development Program of China(No.2003AA321010).
文摘Dimethyl carbonate （DMC） and poly（ethylene terephthalate） was simultaneously synthesized by the transesterification of ethylene carbonate （EC） with dimethyl terephthalate （DMT） in this paper. This reaction is an excellent green chemical process without poisonous substance. Various alkali metals were used as the catalysts. The results showed alkali metals had catalytic activity in a certain extent. The effect of reaction condition was also studied. When the reaction was carded out under the following conditions： the reaction temperature 250℃, molar ratio of EC to DMT 3 ： 1, reaction time 3h, and catalyst amount 0.004 （molar ratio to DMT）, the yield of DMC was 68.9%.
基金Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China(No.2005-383)
文摘Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.
文摘The effects of different treatments, such as dry heat,wet heat, solvent vapor and ultrasonic, on propertiesof the cyclic oligomers on the surface of polyester fiberare studied. The components of surface oligomers areanalyzed through Thin-Layer Chromatograph. Theresult shows that: all of the treatment, especially solvent vapor treatment,call significantly increase the content of surface cyclic oligomers.The content of cyclic triIner is increased more considerably than other oligomers. Moreover,the morphology and thedistribution of surface cyclic oligomers are also different from different treatments:Dry heat and wet heat cause larger polygonal solids distributed evenly on the surface of fiber;solvent vapor nlakes fiber surface exhibit irregular rodlike crystal shapes randomly;ultrasonic treatment induces some obscureand smaller deposi^on the surface of fiber.
