聚苯硫醚对聚醚砜浇铸体性能影响研究

利用热压成型制备了聚醚砜和聚苯硫醚/聚醚砜的浇铸体,并对两种树脂浇铸体吸水性能和力学性能进行了研究。结果表明:以1∶5质量比添加聚苯硫醚到聚醚砜中,热压成型的适宜温度范围增加一倍,复配树脂的抗水分侵蚀能力提高53.7%,抗压缩能力优于单一聚醚砜树脂。在热压温度适宜范围之外,聚醚砜树脂浇铸体力学性能出现大幅下降,复配树脂则下降幅度较小,使用时结构稳定性和安全性较好。     

热压工艺对单向连续碳纤维增强聚苯硫醚/聚醚砜复合材料力学性能的影响

将溶液浸渍法和悬浮液浸渍法结合,通过热压成型制备了以聚苯硫醚/聚醚酚为基体的单向连续碳纤维增强复合材料,研究了不同树脂浓度和热压工艺参数下复合材料的力学性能。结果表明:在以12.5%质量浓度的PES-DMAc溶液体系中,以聚苯硫醚和聚醚砜质量比为1:3复配树脂构成的复合材料综合力学性能优于以单一聚醚砜为基体的复合材料。通过层间剪切强度、弯曲强度、压缩强度和冲击强度的测试,确定了复合材料的最佳加工工艺参数,利用扫描电镜分析了复合材料的在受力断裂时的破坏机理。     

PPS/PES共混物及其碳纤维增强复合材料的热行为特征的研究

应用广角X光散射(WAXS)和示差扫描量热分析(DSC)技术研究了聚苯硫醚/聚醚砜共混物及其碳纤维增强聚苯硫醚/聚醚砜混杂基体复合材料的结构特征和熔融、结晶行为.实验结果表明,(1)聚醚砜和碳纤维的混入未使聚苯硫醚的晶型发生改变,但使聚苯硫醚的结晶规整度降低;(2)碳纤维的混入可引起聚苯硫醚熔点降低,而混入聚醚砜并不引起聚苯硫醚的熔点降低;(3)聚醚砜和碳纤维均对聚苯硫醚存在诱导结晶效应,当碳纤维和聚醚砜共存时,聚本硫醚倾向于在碳纤维表面择优成核结晶.      

溶液共混—共沉淀方法制备PPS／PES共混物的研究

运用示差扫描量热分析(DSC)等技术研究了经溶液共混-共沉淀方法制得的聚苯硫醚/聚醚砜共混物的熔融、结晶及相分离行为。实验结果表明,双氧水处理可使聚苯硫醚发生一定程度的氧化,经双氧水化学处理后的聚苯硫醚较未经处理的聚苯硫醚与聚醚砜有更强的相互作用;共混组分比对聚苯硫醚与聚醚砜的相互作用存在一定的影响;熔融状态冷却结晶时的冷却速率是控制共混物结晶及相分离行为的决定因素。     

聚苯硫醚砜—新型高性能工程塑料

聚苯硫醚砜是一种性能优异的热塑性工程塑料,其突出特点是耐高温性优异。对其合成、性能、增强材料及合金等作了介绍。     

不同热塑性树脂基体对单向碳纤维复合材料吸湿行为的影响

采用溶液浸渍和热压成型分别制备了以聚醚砜和聚醚砜/聚苯硫醚为基体的单向连续碳纤维增强复合材料,研究了不同成型温度下复合材料的层间剪切强度和湿热环境下对水分的吸湿过程。结果表明,添加了聚苯硫醚的复合材料在较佳的加工工艺窗口下可以保持原有的层间剪切强度,同时大幅度地增强复合材料的抗水分侵蚀能力。这是由于聚苯硫醚在热压成型过程中,以聚醚砜为晶核在碳纤维表面结晶,形成较为致密的结构。同时红外分析表明,混合树脂极性较小。二者共同作用,可以提高复合材料在使用过程中的安全性和结构的完整性。性能较好的复合材料吸湿过程符合Fick第二定律。     

PPSS树脂

Phillips 66公司在底待律的 SAE(Society of Automotive Engineers)展览会上展出一种新的无定形聚苯硫醚砜(PPSS)树脂(或称“Rytons”),可挤塑、注塑和吹塑。高温下具有极高的机械强度和优异的耐化学品及溶剂性。PPSS属于聚苯硫醚类,但含有另一芳基,在早期开发阶段称为 PA S-2。     

国外聚苯硫醚树脂合成和后处理进展

聚苯硫醚树脂的合成工艺简单、性能优越、易于加工,预计它将是八十年代较有发展前途的一种新型高分子材料。 1888年就已经有关于聚苯硫醚树脂合成的报道,直到1967年,Edmonds和Hill才报导了由对二氯苯和硫化钠在极性有机溶剂中反应制备聚苯硫醚树脂的方法,1968年美国菲利浦石油公司将此法生产的聚苯硫醚以商品名称“雷通”(Ryton)作了商品性介绍,并且向市场进行了推销。1973年美国菲     

聚苯硫醚的结构改性

为改善聚苯硫醚在某些方面的性质而进行的结构改性,为拓宽其应用起到了积极的作用。本文综述了聚苯硫醚酮、聚苯硫醚砜、聚苯硫醚酰胺和聚苯腈硫醚等几种结构改性的聚苯硫醚的最新研究进展。     

特种工程塑料发展现状和进展

叙述了聚酰亚胺、聚砜、聚苯硫醚、聚醚醚酮和聚醚砜等特种工程塑料的发展现状和市场进展。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from