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Shweta Srivastava Seema Srivastava Shinoo Srivastava Sanjeev John La'Verne Irfan Ali Khan Parvez Ali V. D. Gupta 《应用聚合物科学杂志》2011,122(2):1376-1381
Using Wilson's GF matrix method as modified by Higgs for an infinite system, we report normal modes and their dispersion for polyoxymethylene using the Urey‐Bradley force field. Heat capacity has been evaluated as a function of temperature from dispersion curves via density‐of‐states. The results obtained agree well with the experimental data reported in the literature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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玻璃纤维,碳纤维填充聚甲醛的摩擦磨损性能研究 总被引:3,自引:0,他引:3
利用RFT-Ⅲ往复摩擦磨损试验机测试了玻纤,碳纤填充聚甲醛所形成复合材料的摩擦磨损性能,并利用SEM和XPS研究了其磨损机理,研究发现,填加一定量玻纤,碳纤均可降低聚甲醛的磨损,但填加碳纤效果更好,XPS分析发现钢对偶面上的Fe向玻纤,碳纤复合材料表面发生转移,并生成Fe2O3。 相似文献
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Ternary composites composed of polyoxymethylene (POM), polyurethane (PU), and boehmite alumina were produced by melt blending with and without latex precompounding. Latex precompounding served for the predispersion of the alumina particles. The related masterbatch (MB) was produced by mixing the PU latex with water‐dispersible boehmite alumina. The dispersion of the alumina was studied by transmission and scanning electron microscopy techniques (TEM and SEM, respectively) and discussed. The crystallization of POM was inspected by means of differential scanning calorimetry (DSC) and polarized optical microscopy (DSC and polarized light microscopy, respectively). The mechanical and thermomechanical properties of the composites were determined in uniaxial tensile, dynamic‐mechanical thermal analysis (DMTA), short‐time creep tests (performed at various temperatures), and thermogravimetric analysis (TGA). The melt flow of the composites was characterized in a plate/plate rheometer. In addition, the dielectric response of the nanocomposites was investigated by means of broadband dielectric spectroscopy at an ambient temperature. The composites produced by the MB technique outperformed the direct melt (DM) compounded composites in respect to the thermal and mechanical characteristics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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对SO42-/Fe2O3固体超强酸上三聚甲醛与甲醇开环缩合反应制备聚甲醛二甲基醚(DMMn)的反应条件进行了研究。其中,醇醛比、反应温度和反应时间对产物分布的影响较大。当甲醇与三聚甲醛的物质的量比(即醇醛比)为1.2、反应温度130℃、反应时间2h、反应压力0.1MPa、催化剂用量为总反应物质量的1.5%时,柴油添加组分DMM3-8收率可达22%,同时,SO42-/Fe2O3具有较好的循环使用性能。并运用XRD、SEM、NH3-TPD、IR等表征手段对反应前后催化剂进行了分析。 相似文献
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Core–shell nanoparticles chemically functionalized by hindered amine stabilizer (HAS), poly(BA‐MMA‐co‐PMPA) (PBMP), were prepared by two‐stage emulsion polymerization from butyl acrylate, methyl methacrylate, and 1,2,2,6,6‐pentamethylpiperidin‐4‐yl acrylate. The incorporation of HAS into the particles was confirmed by nuclear magnetic resonance (1H‐NMR) and the core–shell microstructure of PBMP particles was revealed by transmission electron microscopy. Furthermore, PBMP capable of one‐step toughening and photostabilizing, was melt‐blended with polyoxymethylene (POM), and its dispersion in POM was investigated by scanning electron microscope. The results showed that the core–shell nanoparticles could be well dispersed in POM matrix, indicating its good compatibility with POM. The UV resistance and impact resistance of POM were obviously improved by the HAS‐functional core–shell nanoparticles simultaneously. In addition, the core–shell nanoparticles could confer excellent protection to the surface of POM from UV‐light damage, regardless of the adverse effects on the thermal‐oxidative stability of POM, as investigated by thermogravimetry analysis under aerobic condition. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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以聚甲醛(POM)的中国专利数据为分析样本,从中国专利申请的地区分布、时间分布、申请人、技术构成等多角度详细剖析了国内POM专利技术的整体发展状况。结果表明,我国POM产业的技术基础薄弱,研究主要集中于POM共混改性的个别方向,而日本、美国、德国则掌握了从POM合成到POM改性的全面技术,在各个方面对我国POM产业的发展造成压力。建议我国企业和研究机构加大研发力度,尽快开发出具有自主知识产权的POM生产工艺,并继续积极开展改性POM的技术攻关。 相似文献