New Siloxane-Azomethine Alternating Copolymers

Abstract:

Starting from p-hydroxybenzaldehyde and o-dianisidine, the proper fully aromatic bisazomethine diol has been prepared and inserted in new soluble linear polymeric structures by their polycondensation through the OH- groups with α,ω-bis(chloromethyl)oligodimethylsiloxanes having different molecular weights. The structures of the azomethine macromer and derived copolymers were verified by IR, UV, and ¹H NMR. The characterization of the polymers was made by TGA and solubility tests.     

聚氨酯密封膏的研制及力学性能研究

本文研究了聚氨酯密封膏的预聚体、填料、有机硅等因素对其断裂强度、断裂伸长率、硬度等力学性能的影响。发现分子结构不同的预聚体性质不同的填料对其力学性能的影响不同。填料炭黑的补强作用特别强烈。     

Structure-property relations of segmented block copolymers with liquid-liquid demixed morphologies

Poly(propylene oxide) based polyether(ester-amide)s (PEEA) with non-crystallisable amide segments were synthesized and their structure-property relations studied. These model segmented block copolymers were used to gain insight in the structure-property relations of block copolymers with liquid-liquid demixed morphologies, also present in segmented polyurethanes. The poly(propylene oxide) used had a molecular weight of 2300 g/mol and was end capped with 20 wt% ethylene oxide. The non-crystallisable amide segments are based on an amorphous polyamide: poly(m-xylylene isophthalamide) and the repetitive length (x) of the amide segment was varied from 1 to 10. Phase separation in these PEEA's occurred by liquid-liquid demixing when the length (x) of the non-crystallisable amide segment was higher than 2 (x>2). TEM experiments showed spherical structures at two size scales, 5-10 nm domains (nano-domains) and 30-500 nm domains (sub-micron domains), both dispersed in a polyether matrix. The size and volume fraction of these spherical domains were found to increase with increasing the amide segment length. The modulus of the materials increased moderately with increasing amide segment content (increasing amide segment length x). The compression and tensile sets values of these PEEA's were found to decrease with increasing amide segment length, thus these PEEA's behave also more elastic at longer amide contents (thus also at higher modulus). Giving time these liquid-liquid demixed segmented block copolymers recovered completely.     

准确测定聚醚多元醇中间品羟值应注意的问题

本文探讨影响聚醚多元醇中间品羟值准确测定的因素,阐述在检测过程中应注意的事项,以提高检测数据结果的准确度。     

Carbon fiber reinforced polyether ether ketone composite as a bearing surface for total hip replacement

This paper investigates the tribological performance of a carbon fiber reinforced PEEK composite as a bearing surface for total hip replacement. Extensive hip joint simulator tests were conducted to optimize the microstructure of the composite and the counterface material. A softer and more graphitic carbon fiber is preferred to a harder and more abrasive fiber. A ceramic counterface is preferred to a metal counterface. An excellent wear couple was identified to be a 30 wt% pitch-based carbon fiber reinforced PEEK composite acetabular insert articulating against a zirconia ceramic head. When tested on a hip simulator run for 10 million cycles, a reduction in the wear rate of almost two orders of magnitude was achieved with this wear couple in comparison to a conventional UHMWPE/metal or UHMWPE/ceramic couple.     

用50％的水取代CFC11制备聚氨酯硬泡

本文重点介绍了减少50％CFC11发泡剂替代技术研制工作，以国际同类产品为赶超目标，达到绿色标志要求，并已投入生产，本项目获1995年上海市优秀新产品二等奖。     

高分子量聚醚多元醇的研制

在高压反应釜中,采用双金属催化剂,以丙三醇和环氧丙烷为原料,制备了高分子量（Mn≥8000）聚氧化丙烯三醇,其不饱和度为0．010~0．017mol／kg。结果表明,在该体系中,反应最佳条件为：反应温度（85±5）℃,反应时间4~6h,环氧丙烷与丙三醇投料质量比为120／1~200／1,催化剂质量分数为0．12％~0．18％,加适量的溶剂有利于提高聚醚的分子量。     

低不饱和度聚醚多元醇及其催化剂的制备工艺

论述了低不饱和度高分子量聚醚多元醇的特性,对双金属氰化物络合物（DMC）催化剂的类型及其制备方法、低不饱和度聚醚多元醇的制备技术进行了介绍。     

具有对称与不对称封头的聚醚型汽车压缩机润滑油性能对比研究

对比研究了具有对称和不对称封头的两类聚醚型润滑油的性能。结果表明,两类聚醚型压缩机润滑油吸湿性小,两者的相溶性好;聚醚型润滑油封头率越高,吸湿性越小;相比而言,具有不对称封头的聚醚型润滑油比具有对称封头的吸湿性低,润滑性好。这为今后聚醚型润滑油向提高封头率以及聚醚的不对称封头方向发展提供参考。     

聚醚胺汽油清净剂的合成及应用研究

研究了聚醚胺类汽油清净剂的合成、精制及其防锈与清净性能。实验结果表明：在不增加燃烧室积炭（CCD）生成量的前提下,聚醚胺类汽油清净剂对发动机进气阀具有优异的清净性能;将聚醚多元醇、聚醚胺、酰胺醇胺等物质作为携带剂与曼尼希清净剂进行复配,可有效抑制燃烧室沉积物的生成。