Dispersion of Poly(phenylene ether) in a Poly(phenylene sulfide)/Poly(phenylene ether) Alloy

We have devised and developed a new method for the preparation of a poly(phenylene sulfide)/poly(phenylene ether) (PPS/PPE) alloy, which has micro‐dispersed PPE in the PPS matrix. PPS was chemically treated to activate the reactivity of the PPS end‐group by extrusion in the presence of diphenylmethane diisocyanate (MDI) in its molten state at 300°C. The reactive processing of the MDI‐treated PPS with maleic anhydride‐modified PPE gave a PPS/PPE alloy with micro‐dispersed PPE in the PPS matrix. The PPS/PPE alloy showed mechanical properties superior to those of PPS at elevated temperature (150°C) and also showed precision‐molding ability superior to that of PPS.     

聚苯硫醚流变行为研究

采用高压毛细管流变仪研究了进口聚苯硫醚(PPS)树脂的流变性能,分析了剪切速率、温度对PPS树脂流变行为的影响。结果表明,PPS树脂的非牛顿指数均小于1;在低剪切速率下,PPS树脂的表观黏度对温度的依赖程度高于高剪切速率下的依赖程度;PPS树脂的黏流活化能随剪切速率的增加呈减小趋势,其结构黏度指数随温度升高而减小。     

热喷涂用聚苯硫醚树脂的研究

用硝酸和硫酸对聚苯硫醚（PPS）进行处理,所得产物用红外光谱和热分析手段进行了分析,结果表明,在添加硝酸的情况下室温处理6h,产物结构没有明显的改变,但在室温下使用硝酸／硫酸混合酸处理,产物中有砜基存在;在处理温度较高时,聚合物结构中不但发现了砜基结构,还出现了硝基取代基,由于化学反应的影响,处理后PPS的结晶能力显著下降,与未处理的PPS混合后进行热喷涂试验,取得了很好的效果,因而有望用于热喷涂。     

磺化聚苯硫醚砜的制备和性能表征

以浓硫酸为溶剂,发烟硫酸为磺化剂对聚苯硫醚砜的磺化过程,通过改变温度、反应时间、浓硫酸的用量和发烟硫酸的用量这四个因素来探究磺化反应的条件。利用FTIR、热重分析(TGA)、磺化度、比浓黏度和溶解性测试对其结构和性能进行了表征。结果表明,采用磺化时间为2 h,反应温度15℃,浓硫酸8 mL,发烟硫酸与聚苯硫醚砜的质量比为9.5时,可得到磺化度为62.2%,比浓黏度为0.964 mL/g的磺化聚苯硫醚砜。磺酸基的主要分解温度为346℃,主链的分解温度为534℃。其溶解性得到提高,可溶解在介电常数大于20.7的有机溶剂中。     

Crystallization kinetics of pure and fiber-reinforced poly(phenylene sulfide)

Isothermal DSC investigations on pure as well as glass, carbon, and aramid fibre-reinforced poly(phenylene sulfide) (PPS) were carried out in order to obtain informations on the crystallization kinetics, that is, the Avrami exponent, constant, half-time of crystallization, and (final) degree of crystallinity. PPS is a typical representative of semicrystalline polymers with a maximum degree of crystallinity of about 60%. The Avrami exponent reaches values from n = 2.1–2.7 depending on fibre type but independent of crystallization temperature. The system aramid fibre/PPS has a much shorter half-time of crystallization than the other three systems that could be attributed to the high nucleation effect of the aramid fibre surface to PPS. As a consequence of the high nuclei density a transcrystalline zone is built up around the aramid fibre. The relatively low value of the Avrami constant was discussed and a computer simulation attempt was made to understand the measured value quantitatively. © 1994 John Wiley & Sons, Inc.     

聚甲基乙烯基硅氧烷增韧聚苯硫醚的力学性能研究

通过熔融共混制备了聚苯硫醚/无苯基聚甲基乙烯基硅氧烷(PPS/NPMVS)共混物及聚苯硫醚/单苯基聚甲基乙烯基硅氧烷(PPS/SPMVS)共混物,并对该共混物体系的微观形貌及力学性能进行了分析表征。结果表明,弹性体在共混物中均匀分散,弹性体的加入对PPS基体起到明显的增韧效果;当弹性体的含量为3 %（质量分数,下同）时,2种共混材料的增韧性能最佳,PPS/NPMVS共混材料的断裂伸长率相对于PPS基体提高了3.9倍,PPS/SPMVS共混材料的断裂伸长率相对于PPS基体提高了2.4倍;当NPMVS含量为10 %时,PPS/NPMVS共混材料的冲击强度相对于PPS基体提高了1.8倍,当SPMVS含量为3 %时,PPS/SPMVS共混材料的冲击强度相对于PPS基体提高了1.4倍。     

Thermal degradation of poly(phenylene sulfide) and perfluoropoly(phenylene sulfide)

The thermal and oxidative degradation of poly(phenylene sulfide) and perfluoropoly(phenylene sulfide) have been studied by a weight-loss method. The products of breakdown in vacuum have also been analyzed. The poly(phenylene sulfide) is more thermally stable in inert and oxidizing atmospheres than the fully fluorinated analog. The breakdown products can be accounted for by chain scission and transfer reactions. The formation of a large proportion of residue implies that crosslinking reactions play an important part in the degradation.     

Polymerization characteristics and thermal degradation study of poly(phenylene sulfide ketone)

Poly(phenylene sulfide ketone) (PPSK) was synthesized by the reaction of sodium sulfide with 4,4′‐dichlorobenzophenone in N‐methyl‐2‐pyrrolidinone through the Phillips process. The effect of water hydration of sodium sulfide in solution, polymerization temperature, polymerization time, and stoichiometric ratio of monomers on the polymerization behavior of PPSK were investigated with respect to inherent viscosity and yield. Thermal degradation parameters of PPSK synthesized were investigated by dynamic thermogravimetry. To determine thermal degradation energy, Kissinger, Ozawa, and Friedman methods were used and activation energies were 202.3, 233.6, and 232.2 kJ/mol, respectively. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1329–1337, 2000     

聚苯硫醚砜及其复合材料的特性与应用

介绍了聚苯硫醚砜(PPSS)在国内外的发展概况,综述了PISS及其复合材料的物理力学性能、改性技术和成型工艺;着重介绍了PPSS／GF、PPSS／PPS以及PPSS／聚酯共混物的性能,介绍了PISS膜的研究进展并展望了其发展应用前景。     

超支化聚苯硫醚与线性聚苯硫醚的对比表征

以2,4-二氯苯硫酚为原料,采用一步法合成超支化聚苯硫醚。笔者运用红外光谱、拉曼光谱、荧光光谱、示差扫描量热分析、热重分析、广角X-射线衍射、溶解实验等分析手段,对超支化聚苯硫醚和线性聚苯硫醚的基本性能进行了对比。由于两者结构上的差异,使得两者表现出不同的特性。超支化聚苯硫醚具有三取代苯结构,具有很强的荧光效应、完全的不结晶、溶于有机溶剂、热降解温度低于线性聚苯硫醚约60℃等特性。广角X-射线衍射谱图也和结晶、无定型线性聚苯硫醚有很大不同。     

Melting behavior of high performance composite matrix polymers: Poly(phenylene sulfide)

We have been studying crystallization and melting behavior of high performance semicrystalline polymers to increase our understanding of the effects of processing on microstructure. Questions on development of morphology center around whether single or dual populations of crystals exist after melt processing, and how these crystals melt creating the multiple endotherms usually observed. We have used differential scanning calorimetry (DSC) to examine endothermic response in poly(phenylene sulfide), PPS, after various processing treatments. These include isothermal melt crystallization and crystallization from the rubbery amorphous state. For the first time, we report endothermic response of solution crystallized mats of single crystals. Our results on melt crystallized PPS are explained by a model in which different crystal populations exist in the material at room temperature prior to DSC scanning. Ability of the material to reorganize during the scan depends upon the initial state of perfection of the crystals.     

高性能超支化聚苯硫醚大分子结构及特性

超支化聚苯硫醚(HPPS)的分子呈不规则的三维准球形结构,分子中存在大量结构上的缺陷和残缺的支链,还包括部分线性结构单元;官能团部分位于分子表面,部分存在于分子内部;其相对分子质量分布较宽,支化度在0~1之间。介绍了HPPS的合成机理、掺杂导电性,以及其共混材料和嵌段共聚物材料的性能。     

玻纤增强聚苯硫醚复合材料的增韧研究

针对玻纤增强聚苯硫醚材料韧性差的问题，对聚苯硫醚傲璃纤维复合体系的增韧进行了研究，考察了玻纤、改性聚合物、有机超细粒子对复合材料力学性能的影响。采用基体增韧（预增韧）与有机超细粒子增韧技术，在保持复合材料拉伸强度和模量的同时，较大地提高了冲击强度，获得了综合力学性能优异的纤维增强聚苯硫醚材料。     

Study on Polymerization Conditions and Structure of Poly(phenylene Sulfide Sulfone)

High molecular weight linear poly(phenylene sulfide sulfone)s (PPSS) were prepared by aromatic nucleophilic substitution reaction at atmospheric pressure. Influences of various polymerization conditions, such as solvent, catalyst, molar ratio, reaction temperature and time, on the molecular weight of PPSS were examined. The intrinsic viscosity of PPSS obtained under optimum synthesis conditions according to orthogonal experiments was 0.55 dl/g. The results of FT-IR, ¹H-NMR, UV spectrum and Raman spectrum confirmed the linear chain nature of product. The maximum UV absorption of PPSS increased with the increase of its intrinsic viscosity. X-ray diffraction and SALS studies indicated that some local ordered structures formed in the samples annealed between 220 ^○C∼240 ^○C for 4 h. The improvement in thermal performance of PPSS of high molecular weight was confirmed by DSC and TGA experiments.     

聚苯硫醚皮芯复合纤维的性能研究

以聚苯硫醚(PPS)树脂和聚对苯二甲酸乙二醇酯(PET)树脂为原料,采用复合纺丝技术,制得PPS-PET皮芯复合纤维。对纯PPS纤维和PPS-PET复合纤维分别进行了紫外线照射、热处理和耐酸碱处理,对比了两者处理后的力学性能变化,验证了复合纤维应用的可行性。试验结果表明:PPS-PET皮芯复合纤维的耐热性能略低于PPS纤维;而经过同等强度的紫外光辐照后,PPS-PET皮芯复合纤维的强度保持率是PPS纤维的2倍左右;在试验条件下经过酸、碱浸泡后,PPS-PET皮芯复合纤维的强度保持率与PPS纤维相比未表现出明显差异。性能研究结果表明:通过复合纺丝,PPS纤维的综合性能有所改善。     

聚苯砜树脂聚合脱水工艺对比

对比研究了聚苯砜(PPSU)树脂聚合过程中闭环脱水工艺和传统连续通氮脱水工艺两者的尾气排放量和物料损耗情况,并采用高压毛细管流变测试、力学性能测试、高温注塑等方式,系统地评估了闭环脱水工艺对树脂热稳定性和力学性能的影响,发现闭环脱水工艺的效果较原连续通氮脱水工艺更优异.闭环脱水工艺制备所得到的PPSU树脂热稳定性和力学...     

Elastomer-toughened poly(phenylene sulfide)

For use as electrical and electronics parts, or automobile and mechanical parts, toughened poly(phenylene sulfide) (PPS) is desired. For these applications, our investigation centered on improving the toughness of PPS and developing elastomer-toughened PPS and elastomer-toughened compounds of PPS. Using chemically treated PPS and an olefinic elastomer with a functional group, we developed elastomer-toughened PPS using a reactive processing method. In the PPS matrix, the elastomer is finely dispersed. While the notched Izod impact strength of the original PPS is about 1 kg · cm/cm. clastomer-toughened PPS has a notched impact strength around 50 kg · cm/cm. The notched fracture surface of elastomer-toughened PPS is observed using a scanning electron microscope. We concluded that the mechanism for the toughening is attributed to energy dissipation by matrix yield.     

Thermal studies of blends of poly(phenylene sulfide) (PPS) with poly(phenylene sulfide sulfone) (PPSS) and with poly(phenylene sulfide ether) (PPSE)

The miscibilities of poly(phenylene) sulfide/poly(phenylene sulfide sulfone) (PPS/PPSS) and poly(phenylene) sulfide/poly(phenylene sulfide ether) (PPS/PPSE) blends were invesigated in terms of shifts of glass transition temperatures T_g of pure PPS, PPSS, a dn PPSE. The crystallization kinetics of PPS/PPSS blends was also studied as a function of molar composition. The PPS/PPSS and PPS/PPSE blends are respectively partially and fully miscible. PPSE shows a plasticizing effect on PPS as does PPS on PPSS, which necessarily improves te processibility in the respective systems. We can control T_g and melting temperature T_m of PPS by varying amounts of PPSE in blends. The melt crystallization temperature T_mc of PPS/PPSE blends was higher than that of the PPSE homopolymer. Therefore, these blends require shorter cycle times in processing than pure PPSE. The overall rate of crystallization for PPS/PPSS blends follows the Avrami equation with an exponent ?2. The maximal rate of crystallization for PPS/PPSS blends occurs at a temperatre higher by 10°C than that for PPS, while the crystallization half time t_1/2 is 4 times shorter. In the cold crystallization range, crystal growth rates increase and Avrami exponents decrease significantly as the temperature increases.     

Microstructure and Properties of Microcellular Poly (phenylene sulfide) Foams by Mucell Injection Molding

A series of microcellular poly (phenylene sulfide) (PPS) foams were prepared by Mucell injection molding. The cell structure, mechanical properties, crystallization behavior and dielectric property of microcellular PPS foams were systemically investigated. The results showed that the longer the length of flow passage of injection mold, the larger cell size of microcellular PPS foams. The injection parameter of shot size played an important role in relative density of microcellular PPS foams. When the relative density of microcellular PPS foam reached to 0.658, the tensile strength, flexural strength and impact strength of PPS foam materials achieved 10.82 MPa, 52.99 MPa and 0.305 J/cm², respectively. Meanwhile, with the relative density decreasing, the dielectric constant of PPS foam materials reduced, while the volume resistivity of its uprated.     

Synthesis and characterization of poly(phenylene sulfide), poly(2-methylphenylene sulfide), and poly(2,6-dimethylphenylene sulfide)

A facile synthesis of poly(phenylene sulfide) (PPS), poly(2-methylphenylene sulfide) (PMPS), and poly(2,6-dimethylphenylene sulfide) (PDMPS) from the respective copper (I) bromothiophenoxides is described. Polymerization was effected in a 10:1 quinoline:pyridine mixture at atmospheric pressure and conditions optimized for the preparation of high-molecular-weight materials. The preparation of PPS in pyridine under pressure at 250°C has been investigated for comparative purposes. Yields and the properties of materials produced by solution polymerization are comparable to or better than those produced in the autoclave reaction. Properties have been investigated as a function of reaction time and molecular weight, and the deficiencies of the molecular-weight assessment methods are discussed. PMPS and PDMPS have been similarly studied and their properties evaluated. The use of heat of crystallization determinations for molecular-weight studies on PPS are described and critically evaluated.