为了改善纳米碳酸钙在聚氯乙烯(pvc)基体中的分散性和相容性,分别采用十八胺、十二胺和辛胺与马来酸酐反应,制备出三种改性剂;然后分别用这三种改性剂对纳米碳酸钙进行湿法改性,制备了PVC/纳米碳酸钙复合材料,系统研究了改性纳米碳酸钙对PVC复合材料力学性能的影响.结果表明:三种改性剂均可以与纳米碳酸钙表面结合,阻止了纳米碳酸钙的团聚,改性后的粒子可以均匀地分散在PVC基体中;三种改性剂改性的纳米碳酸钙都可以显著提高PVC复合材料的缺口冲击强度,但其弯曲强度和拉伸强度变化不大.

分别采用十八胺、十二胺和正辛胺对纳米CaCO3进行湿法改性,制备了聚氯乙烯(PVC)/纳米CaCO3复合材料,系统研究了不同改性剂改性的纳米CaCO3对PVC基复合材料力学性能的影响.结果表明:3种改性剂均可以与纳米CaCO3表面结合,形成一有机层,阻止了纳米CaCO3团聚,使改性后的粒子可以均匀分散在PVC基体中;十八胺、十二胺和正辛胺改性后的纳米CaCO3均可显著提高PVC复合材料的缺口冲击强度,并且随着改性剂分子链长度的增加,冲击强度也略有提高;改性纳米CaCO3可以略微提高复合材料的弯曲强度,但材料的拉伸强度略有下降.

To improve the dispersion and compatibility of nano-CaCO3in PVC( polyvinyl chloride) matrix,PAMs were synthesized respectively by single esterification with the phthalic anhydride and butyl alcohol,octanol,cetyl alcohol,diethylene glycol monobutyl ether, and the corresponding phthalic acid single esterification sodium salt was prepared with phthalic acid monoester( PAM) adding with right amount of NaOH aqueous solution. Wet modification was used to treat the surface of nano-calcium carbonate which was then added into PVC matrix to study the properties of PVC. Through mechanical testing, torque rheometer and SEM,the effect of nano-CaCO3on the mechanical and processing properties of PVC was studied. It could conclude that the impact strength of PVC / nano-CaCO3composites increased with the length increasing of carbon chain and the PVC composite had a better performance if the organic group in the modifiers had a certain polarity.

以苯基三甲氧基硅烷和乙烯基三甲氧基硅烷为原料,在金属离子诱导作用下水解缩聚制得具有环形结构的三苯基三硅氢环三硅氧烷和六乙烯基环六硅氧烷,并用FTIR和1H NMR对其进行表征。合成的三苯基三硅氢环三硅氧烷和六乙烯基环六硅氧烷通过硅氢加成制得的硅树脂不仅具有高的透光率和硬度,而且具有很好的耐热性能,所得硅树脂在484℃才出现明显的热分解,1 000℃时的质量保持率达80%。

采用种子乳液聚合法合成了丙烯酸酯类聚合物(ACR)胶乳,其中核层及中间层为不同交联程度的聚丙烯酸丁酯(PBA),壳层为聚甲基丙烯酸甲酯(PMMA).玻璃化转变温度(Tg)和拉伸性能的测定表征了ACR的自身性能;聚氯乙烯(PVC)冲击强度的测定和PVC断面的扫描电子显微镜(SEM)分析表征了ACR增韧后的PVC的性能.结果表明:ACR内部结构及外界温度对增韧效果有重要影响;测试温度大于15℃时,核层交联度为6％ ～ 12％时,ACR增韧效果最佳.

A series of poly(butyl methacrylate)(PBMAP) oligomers with different relative molecular weights were prepared using butyl methacrylate(BMA) as monomer and azodiisobutyronitrile(AIBN) as initiator at different temperatures and oxygen pressures.The structure of PBMAP was characterized by IR.NMR and EL.The relative molecular weight of PBMAP was measured by GPC.Thermal properties of PBMAP were analyzed by DSC and TG.The initiation ability of PBMAP on free radical polymerization of BMA at different temperatures was investigated.The results show that PBMAP is a random copolymer of BMA and oxygen.PBMAP can initiate free radical polymerization above its decomposition temperature.

To improve the dispersion and compatibility of nano-CaCO3in PVC matrix,the phthalic acid ethylene glycol monobutyl ether ester sodium salt(PAE) was prepared through single-esterification with phthalic anhydride and ethylene glycol monobutyl ether and neutralization was with NaOH aqueous solution.Utilizing wet modification was used to treat the surface of nanometer calcium carbonate which was then added into PVC matrix to study on the toughing in polyvinyl chloride(PVC).PAE was better than the common surface modifier sodium stearate through impact strength,tensile,TEM,SEM and other tests; it significantly improved the impact strength of PVC without reducing of modulus and strength at the same time.

The bulk copolymerization of trifluoromethyl methacrylate（TFEMA） and isobornyl methacrylate（IBOMA） using azodiisobuty-ronitrile（AIBN） as initiator was studied with emphasis on the reactivity ratio of two monomers and the copolymer properties with various monomer doses.The monomer reactivity ratios were calculated by using KT and FR graphical methods and YBR calculative method.The result indicates that the reactivity ratios of TFEMA and IBOMA are 3.693 and 0.263,respectively.Glass transfer temperature,refraction index and transparence of the copolymer were determined by differential scanning calorimetry,Abbe refractometer and visible ultraviolet spectrophotometer,respectively.

The copolymerization of hexafluorobutyl methacrylate(HFBMA) and butyl methacrylate(BMA) was performed in a bulk copolymerization system at high temperature.The reactivity ratios of two monomers and the copolymer's property were measured.The monomer reactivity ratios were calculated by using two graphical methods,KT and FR methods,and YBR calculative method.The result indicated when the temperature was 80 ℃,120 ℃ and 150 ℃,the reactivity ratios of HFBMA and BMA were r HEBMA = 0.717 and r BMA = 0.689,r HEBMA = 0.792 and r BMA = 0.773,r HEBMA = 0.829 and r BMA = 0.776 respectively. The copolymer composition curves of HFBMA and BMA were obtained.Effects of copolymer composition on the glass transition temperature,thermal decomposition temperature,refraction index and light transmittance of the copolymers were investigated.The refraction index,glass transition temperature and initial decomposition temperature of the copolymer were about 1.409-1.483,21 ℃-46 ℃,260 ℃-280 ℃ respectively.The copolymer has a good performance of light transmittance.

The process of static adsorption of water and hydroquinone on 4A molecular sieve in methyl methacrylate(MMA)at different temperature were investigated.The saturated adsorption capacity of water on 4A molecular sieve in MMA with different water content were calculated and analyzed.The results showed that 4A molecular sieve activated at high temperature had good saturation adsorption on water and hydroquinone in MMA.

The thermal properties of perfluorosulfonated ionomer (PFSI) precursors, H-type, and Na-type PFSIs with various ion exchange capacity of 0.36, 0.88, 1.02, and 1.20 mequiv./g in the form of pellets were investigated by thermogravimetry and differential scanning calorimetry. It is revealed that the Na-type PFSIs have the highest thermal stability, and the mechanism of thermal degradation of H-type PFSIs is different from those of precursors and Na-type PFSIs. The DSC measurements indicate that the thermal behaviors of the precursors, the H- and Na- type PFSIs are very different due to the difference of the end groups of the pedants.

The morphology of perfluorosulfonic ionomer molecules in N,N-dimethylformamide was investigated at different concentrations. Rheological, dynamic light scattering (DLS), and scanning electron microscopy (SEM) measurements were performed on the prepared perfluorosulfonic ionomer solutions or films. The ionomer molecules shrank from rodlike granules to spherelike ones at relatively low concentrations, and the spherelike granules aggregated together to form aggregates at higher concentrations, with capillary liquid bridge force as the driving force. As the solvent evaporated slowly at room temperature, the SEM image showed that the film was loosely stacked by granules and that aggregates formed in the solution. (c) 2007 Wiley Periodicals, Inc.

To investigate the solution-cast process from concentrated DMF-based perfluorosulfonic ionomer (PFSI) solution to membranes and morphology of the corresponding solution-cast membranes, XRD measurements were conducted on concentrated solutions, gels of various ionomer concentrations and membranes prepared at different temperatures, and small-angle X-ray scattering from the membranes was studied in order to investigate their internal supermolecular structure. It is with interaction of backbones of the ionomer molecules that the PFSI aggregates in the solutions fuse into each other to form gels and membranes, with capillary liquid bridge force and thermal movement of the polymer chains as the driving force on drying. Fusion degree of the ionomer aggregates increases with increasing casting temperature. Accordingly, proton conductivity, water uptake, solubility in ethanol/water mixture and crystallinity of the membranes decrease with increasing casting temperature, whereas dry density and tensile stress at break of the solution-cast membranes increase. SEM and TEM measurements were also conducted to give direct observation of the structure of the membranes. It was also found that morphology of DMF-based solution-cast PFSI membranes is greatly different from that of Nafion® thermo-extruded perfluorosulfonic membranes.

Perfluorosulfonated ionomer (PFSI) was synthesized and PFSI membranes were prepared via a solution-cast method and annealed at different temperatures from 150 to 230 degrees C. The annealing effect on water content, proton conductivity, and methanol permeability were reported and discussed. X-ray diffraction and small angle X-ray scattering were used to test the structure of the membranes. It was found that annealing increased the proton conductivity of the membranes because heat-treatment helped to free the sulfonic groups that were buried in the polymer segments and form more organized ionic clusters. Water content and methanol permeability of the annealed membranes decreased with increasing annealing temperature. Simultaneously, annealing induced more compact chain packing structure, which eventually affected the transport of the proton and methanol through these ionomer membranes. (C) 2007 Wiley Periodicals, Inc.

Ion exchange resin immobilized Co(II) catalyst with a small amount of soluble CuCl2/Me6TREN catalyst was successfully applied to atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in DMF. Using this catalyst, a high conversion of MMA (>90%) was achieved. And poly(methyl methacrylate) (PMMA) with predicted molecular weight and narrow molecular weight distribution (M-w/M-n = 1.09-1.42) was obtained. The immobilized catalyst can be easily separated from the polymerization system by simple centrifugation after polymerization, resulting in the concentration of transition metal residues in polymer product was as low as 10 ppm. Both main catalytic activity and good controllability over the polymerization were retained by the recycled catalyst without any regeneration process. (C) 2008 Wiley Periodicals, Inc.

Perfluorosulfonated membrane was prepared through solution-casting method from perfluorosulfonated resin, which was synthesized in lab via copolymerization of tetrafluoroethylene,hexafluoropropylene and perfluoro[2-(2-fluorosulfonylethoxy) propyl vinyl ether]. Analysis of TGA shows the membrane has excellent thermo-stability, id est the decomposition temperature rises to 400℃. The DSC plot shows three transition temperatures that are respond to the amorphous region, ionic clusters and the crystallization phase respectively. The mechanical property, electrochemical and chemical-resistant properties of the membrane were examined and compared to those of Nafion~ NR-112 membrane from DuPont company.