Synthesis of copolymer from 1,3,5‐trioxane and 1,3‐dioxolane catalyzed by Maghnite‐H+

Copolymers (polyoxymethylene) were prepared by cationic copolymerization of 1,3,5‐trioxane (TOX) with 1,3‐dioxolane (DOX) in the presence of Maghnite‐H⁺ (Mag‐H⁺) in solution. Maghnite is a Montmorillonite sheet silicate clay, with exchanged protons to produce Mag‐H⁺. Various techniques, including ¹H‐NMR, ¹³C‐NMR, FT‐IR spectroscopy, and Ubbelohde viscometer were used to elucidate structural characteristics properties of the resulting copolymers. The influence of the amount of catalyst, of dioxolane (DOX), temperature, solvent, and time of copolymerization on yield and on intrinsic viscosity of copolymers was studied. The yield of copolymerization depends on the amount of Mag‐H⁺ used and the reaction time. We also propose mechanisms involved in the synthesis of copolymer (polyoxymethylene). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

2012年聚甲醛市场分析

介绍了2012年国内外聚甲醛(POM)的供应、需求以及进出口和消费情况,对2008～2012年的价格走势进行了分析并对未来走势进行了预测。分析了2007～2012年的供需平衡情况。从POM的生产工艺、技术改进以及应用开发、品种多样化等方面提出了发展建议。     

甲缩醛与三聚甲醛合成聚甲氧基二甲醚反应速率研究

为了探究反应条件对聚甲氧基二甲醚合成的影响,采用对甲基苯磺酸改性的强酸性阳离子交换树脂为催化剂,在固定床反应器中考察了甲缩醛和三聚甲醛合成聚甲氧基二甲醚的催化活性并研究了反应速率方程。结果表明,该催化剂具有较好的催化活性,三聚甲醛的转化率达到95%以上。根据连串反应机理,建立了幂函数反应速率方程,采用四阶龙格库塔方法对反应速率方程进行计算,使用粒子群算法(Particle Swarm Optimization)对反应速率方程参数进行了拟合回归。结果表明,该反应速率方程能较好地反映甲缩醛和三聚甲醛的转化率以及产物分布,为反应器模拟以及放大生产提供了基础数据。     

油酸聚乙二醇酯对聚甲醛抗静电及力学性能的影响研究

研究了油酸聚乙二醇酯对聚甲醛电学性能及力学性能的影响,实验结果表明,油酸聚乙二醇酯能极大的降低聚甲醛的体积电阻,具有优异的抗静电效果。油酸聚乙二醇酯添加量为1份时,体积电阻率降为107Ω·cm数量级,最低体积电阻率可达106Ω·cm数量级。同时,油酸聚乙二醇酯的添加提高了聚甲醛的缺口冲击韧性,但聚甲醛的强度有所下降。     

Study on the thermal conductive polyoxymethylene/graphite composites

The thermal conductive composites of polyoxymethylene (POM)/graphite were prepared through four intercalation methods, including melt (MI), solution (SM), pan milling (SMI), and in situ intercalation (IM). For the purpose of improving the interfacial compatibility of POM/graphite, realizing the exfoliation and nano‐dispersion of graphite in POM matrix, the effect of the type and the content of the graphite, the nature of the coupling agents used in graphite modification on the properties of the composites was studied. The results showed that the thermal conductive properties of POM were improved remarkably from the value of 0.36 W/(m K) for neat POM to the value of 1.15 W/(m K) in presence of 30 wt % graphite, and the composites filled with the coupling agent T‐1 or T‐2 surface‐modified colloidal graphite displayed better thermal conductivity. The degree of layers exfoliation of the graphite was enhanced in the order of MI, SM, SMI, and IM. And the composites prepared by SM, SMI, and IM methods presented much more decreased size, more narrow size distribution, thinner overlapped sheets, and better dispersion of the graphite than that prepared by MI method. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚甲醛与聚四氟乙烯高分子合金的研究与开发

研究了改性PTFE与POM合金的力学及摩擦磨损性能，从而得到了一种解决PTFE与其它有机高分子合金相容性的方法，为开发含氟高分子合金奠定了基础。     

高抗冲POM／OOPA共混物的研制

研究了原料配比、制样工艺条件对聚甲醛／三元共聚酰胺(POM／COPA)共混物力学性能的影响，并用红外光谱仪、差热分析仪及扫描电镜对共混物中两相间存在的相互作用及共混物的微观形态结构进行了研究。结果表明COPA加入量及制样工艺条件对共混物的冲击强度有较大影响，共混物中POM与COPA分子间存在氢键作用。     

聚甲醛工程塑料及其发展方向

介绍聚甲醛(POM)工程塑料的发展历程、生产方法、性能及应用情况,综述了国内外POM的物理改性研究进展状况,并探讨了POM工程塑料今后的发展方向。     

Scratch and indentation tests on polyoxymethylene (POM)

Scratch and indentation tests were performed on a polyoxymethylene homopolymer that was molded using three different mold temperatures. The different microstructures that developed during processing were studied by examining two samples for each mold temperature at different depths. During the scratch tests, the normal and the tangential force were recorded. The tests on the “as-molded” surface, in comparison to those that were polished until 1 mm of the material was removed, showed extrema of the normal force at a scratch depth that correspond to the interface of different regimes in the microstructure. The first extremum was considered to be caused by the breaking of the skin layer of the polymer (as a result of the rapid cooling process in the mold). Further extrema correspond to the permeation of the transition zone of the indenter into the spherulitic core of the sample. Indentation tests that were made on the same samples showed that the skin had a slightly lower hardness than the bulk of the polymer and that the difference in hardness decreases with increasing mold temperature. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1985–1996, 1997