耐热树脂共混物的界面增容研究

研究了PMR型聚酰亚胺(PI)增容聚芳醚酮(PEK-C)/聚苯硫醚(PPS)共混物的热学性能、力学性能及其形态结构,对PMR型PI在PEK-C/PPS共混物中所起的增容作用机理进行了初步的探讨。实验发现,热固性聚合物预聚物可用于增容热塑性聚合物共混体系,这种增容方法有其特殊性和新颖性,增容后的PEK-C/PPS共混物的力学性能得以改善。

Reactive reinforcement of the interface of high performance polymer blends by PMR-POI

The effect of PMR-polyimide(POI) as the interfacial agent on the interface characteristics, morphology features and crystallization of poly (ether sulfone) /poly (phenylene sulfide) (PES/PPS) and poly(ether ether ketone)/poly (ether sulfone) (PEEK/PES) partly miscible blends were investigated by means of the scanning electron microscopy, WAXD and XPS surface analysis. It is found that the interfacial adhesion was enhanced remarkably, the size of the dispersed phase particles was reduced significantly and the miscibility was improved by the addition of POI. During melt blending cross-link and/or grafting reaction of POI with PES, PEEK and PPS homopolymers was detected, however the reaction activity of POI with PPS was much higher than that of PES and PEEK. It was also found that POI was an effective nucleation agent of the crystallization of PPS.

Electrochemical and in situ spectroelectrochemical behavior of 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and (Zn(II)OHTTAP)

The characterization of free base porphyrin 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and its zinc(II) complexes [Zn(II)OHTTAP] containing eight thioether groups at the beta -pyrrole positions of the macrocycle was reported. Results obtained by cyclic voltammetry and differential pulse voltammetry indicated a five-electron reduction in five steps for each complex. They were oxidized in two single-electron-transfer steps to yield pi -cation radicals and dications and reduced in three single-electron-transfer steps to yield pi -anion radicals, dianions and trianions, respectively. The redox property of H(2)OHTTAP was unusual as compared to porphyrins (PPs) and phthalocyanines (Pcs). Each process was monitored by in situ thin-layer spectroelectrochemistry, which indicated that only the Ligand was electroactive. The existence of the eight hexylthio groups was responsible for the intrastack interactions and enhanced intracolumnar and intercolumnar electron motions, resulting in improved conductivity. Copyright (C) 2001 John Wiley & Sons, Ltd.

聚酰亚胺对高性能树脂共混体系界面的反应增强

研究了以 5 -降冰片烯 -2 ,3-二羧酸单甲酯为端基的 PMR型聚酰亚胺 ( POI)作为界面介质对部分相容的聚醚砜 /聚苯硫醚 ( PES/ PPS)、聚醚醚酮 /聚醚砜 ( PEEK/ PES)共混体系的界面性质、形态结构及结晶行为的影响 .结果表明 ,POI可以有效地增强两相间的界面粘结 ,显著降低 PPS/ PES共混物中 PPS分散区的尺寸 ,改善两组分间的相容性 .在熔融共混过程中 ,POI从本体向界面扩散并同 PPS,PES产生交联和 /或接枝 ,POI同 PPS的反应活性远高于 PES,但 POI与 PES发生反应 . POI是 PPS结晶的有效成核剂

Synthesis of poly(phenylenesulfidephenylenamine) by self-polycondensation of methyl-(4-anilinophenyl) sulfide with antimony pentachloride

Poly(phenylenesulfidephenylenamine)(PPSA) an alternating copolymer and the hybrid structure of poly(phenylene sulfide)(PPS) and polyaniline(PAn), was synthesized by self-polycondensation of methyl-(4-anilino-phenyl) sulfide with antimony pentachloride and by the acid-induced self-polycondensation of methyl-(4-anilino-phenyl) sulfoxide.

Effect of physical aging on phenolphthalein polyethersulfone/poly(phenylene sulfide) blend .1. Mechanical properties

The effect of physical aging at 210 degrees C on the mechanical properties of phenolphthalein polyether sulfone (PES-C) and a PES-C/poly(phenylene sulfide) (PPS) blend, with 5% content of PPS, were studied using DMA, tensile experiments, an instrumented impact tester, and SEM observations. The blend shows good mechanical properties in comparison with the corresponding PES-C. The mechanical properties of both materials exhibit characteristics of physical aging, with only the aging rate of the blend relatively slower, which should be attributed to the constraint effect of PPS particles and the good interfacial adhesion. The morphology of the PPS phase in the blend did not change with aging time. The principal role of PPS particles is to induce crazes, which dissipate energy, under applied loading; thus, the blend shows good toughness. On the other hand, the multiple crazing mechanism depends on the molecular mobility or structural state of the matrix. (C) 1996 John Wiley & Sons, Inc.

Enhanced glass fiber-reinforced phenolphthalein poly(ether ketone) composites by blending poly(phenylene sulfide)

The mechanical properties of glass fiber-reinforced phenolphthalein poly(ether ketone)/poly(phenylene sulfide) (PEK-C/PPS) composites have been studied. The morphologies of fracture surfaces were observed by scanning electron microscope. Blending a semicrystalline component, PPS, can improve markedly the mechanical properties of glass fiber-reinforced PEK-C composites. These results can be attributed to the improvement of fiber/matrix interfacial adhesion and higher fiber aspect ratio. (C) 1996 John Wiley & Sons, Inc.

THERMAL-DECOMPOSITION PROCESSES OF SOME ELECTRICALLY CONDUCTING POLYMERS INVESTIGATED BY DIRECT PYROLYSIS MASS-SPECTROMETRY

Thermal decomposition processes of poly(thio-1,4-phenylene) (PPS), polythiophene (PT) and polyaniline (PAn) were investigated by direct pyrolysis EI or CI mass spectrometry (DPMS). They can provide up to heptemer pyrolynates and give some structure properties. The results indicate that the thermal degradation all undergoes in radical decomposition, PPS pyrolyzes into linear and cyclic oligmers, but PT and PAn pyrolyze only into linear oligmers.

THERMAL AND MECHANICAL-PROPERTIES OF PHENOLPHTHALEIN POLYETHERSULFONE POLY(PHENYLENE SULFIDE) BLENDS

The thermal and mechanical properties of phenolphthalein polyethersulfone/poly(phenylene sulfide) (PES-C/PPS) blends were studied using a differential scanning calorimeter, a dynamic mechanical analyzer, and mechanical characterization. The morphologies of fracture surfaces were observed by scanning electron microscopy. The blends are multiphase systems with strong interaction between the two phases. It is of interest that, although the strength and ductility of PPS are lower than those of PES-C, the addition of PPS can improve markedly the impact strength of PES-C without changing its higher strength. The PPS can also act as a flow aid for PES-C. (C) 1995 John Wiley and Sons, Inc.

几种导电聚合物热分解行为的直接裂解质谱研究

本文用直接裂解低能电子轰击电离和化学电离质谱(DPMS)等方法研究了聚对苯硫醚(PPS)、聚噻吩(PT)和聚苯胺(PAn)的热分解行为和某些结构性质,能提供多至7个链节重复单元的裂解碎片.结果表明:几种聚合物的热分解均以自由基方式降解,PPS形成环状和线状齐聚物,PT和PAn只能形成线状齐聚物.

酞侧基聚芳醚砜/聚苯硫醚共混物的断裂韧性

本文通过有缺口和无缺口冲击试验、断裂韧性测试以及结合扫描电镜分析断面形貌,研究了酞侧基聚芳醚砜/聚苯硫醚共混物的断裂行为,讨论了聚苯硫醚增韧聚芳醚砜的机理.结果表明,共混物冲击强度的改善主要是由于其裂纹引发能的提高;共混物断裂韧性提高的原因是由于外加应力场在PPS微纤附近产生应力集中,促使基体和微纤都发生塑性形变,从而吸收更多的能量所致.

从工程塑料到超工程塑料

简要介绍重要工程塑料的优缺点,着重讨论聚芳醚、聚芳酮、聚芳砜、聚芳酯及液晶类聚合物、聚芳酰胺以及聚酰亚胺类等主要超工程塑料的合成、性能及发展趋势,指出PPS及PEEK是特别值得密切注意的两个品种。