双酚A型邻苯二甲腈树脂改性硅炔杂化树脂及其复合材料性能

采用双酚A型邻苯二甲腈预聚树脂(BAPh-P)改性聚(间二乙炔基苯-二甲基硅烷)树脂(PDMP)制备了双酚A型邻苯二甲腈/聚(间二乙炔基苯-二甲基硅烷)树脂(PBA),利用DSC、FTIR、流变分析、TGA等技术分析其固化行为、黏度以及耐热性变化。结果表明,PBA树脂固化峰值温度较PDMP升高;固化反应主要为炔基的Diels-Alder和加成反应、氰基进一步交联生成三嗪环和酞菁环等结构反应;BAPh-P的加入提升了PDMP在空气下的耐热性,PBA-1(PDMP:BAPh-P质量比为5∶1)树脂固化物在N₂和空气氛围质量损失5%的温度(T_d5)分别为640.6℃和591℃,1000℃质量保留率为89.0%和26.9%;随着BAPh-P质量增加,PBA树脂固化物T_d5呈下降趋势,但空气中T_d5均高于PDMP;石英纤维增强PBA树脂基(QF/PBA)复合材料随BAPh-P质量增加室温弯曲强度逐渐升高,高温弯曲强度先升高后降低;其中QF/PBA-2复合材料室温和400℃弯曲强度分别为363 MPa和330 MPa,较PDMP分别提升91%和214%,室温和400℃的层间剪切强度(ILSS)分别为37.5 MPa和22.2 MPa。      

聚(间二乙炔基苯-苯基氢硅烷)树脂的合成及性能

以苯基三氯硅烷和间二乙炔基苯为主要原料,采用格氏试剂法制备了一种耐高温硅炔树脂聚(间二乙炔基苯-苯基氢硅烷)(PDBS);通过红外光谱、核磁共振和凝胶渗透色谱进行了结构表征,利用差示扫描量热分析、动态红外、流变分析和热重分析研究了聚合物的固化行为和耐热性能。结果表明,间二乙炔基苯与苯基三氯硅烷摩尔比的增加,能够提高PDBS树脂的相对分子质量。此外,随着树脂中硅含量的增加,其固化温度逐渐降低,热稳定性逐渐提高。PDBS树脂固化起始温度为175℃,其固化物具有良好的耐热性能,氮气氛围中失重5%时的温度(Td5)为627.3℃,1000℃时质量保留率为90.2%。     

含苯并噁嗪结构聚三唑树脂的合成与性能

聚三唑树脂是一种新型高性能热固性树脂,为满足高精度构件要求,本研究首先合成了二乙炔基双酚A型苯并噁嗪(BA-apa),并利用BA-apa,N,N,N',N'-四炔丙基-4,4'-二氨基二苯甲烷(TPDDM)与4,4'-联苯二苄基叠氮(BPDBA)的点击加成反应合成了一种含苯并噁嗪结构的低固化收缩聚三唑(BAPTA)树脂...     

聚乙烯基三苯乙炔基硅烷的热分解动力学

为研究聚乙烯基三苯乙炔基硅烷树脂的热分解机理,利用TG-DTG技术探讨了聚乙烯基三苯乙炔基硅烷树脂的非等温热分解过程.借助非模型拟合法和模型拟合法分析了聚乙烯基三苯乙炔基硅烷树脂(PVTPES)的热分解行为,建立了动力学函数,得到了聚乙烯基三苯乙炔基硅烷树脂的热分解反应机理.结果表明,6种热分析方法计算得到PVTPES的热分解活化能(E)在240 k J/mol左右,指前因子lg A=15.51,机理符合三维(3D)扩散控制机理.聚合物PVTPES的热分解过程分析进一步证实芳炔单体的热聚合为环三聚反应.     

苯乙炔封端聚芳醚酮类预聚体、制备方法及用作交联材料

本发明涉及一种新型苯乙炔封端的聚芳醚酮类预聚体、预聚体的制备方法及预聚体在制备高性能交联材料方面的应用。首先制备卤素取代的二苯甲酮类化合物，再使之与苯乙炔在钯催化下发生偶联反应制备含氟的苯乙炔封端单体。     

对二乙炔基苯与苯乙炔的共聚及共聚物的表征

本文用(Ph_3P)_2PdCl_2为催化剂,合成出对二乙炔基苯(PDEB)与苯乙炔(PhA)共聚物。实验结果表明,当PDEB/PhA(摩尔比)小于1/5时,共聚物可溶可熔,大于1/5时,共聚物不溶不熔,等于1/5时可分为两个组分,前者可熔但不溶,后者可溶可熔。不熔组分的最良溶剂是苯,溶解度参数为9.15cm~(-1.5)·cal~(0.5)。对不溶组分测定了比重、溶胀度,Huggins参数和相邻两交联点间的平均分子量。红外光谱分析表明共聚物具有反式结构,并在共聚物中含有少量未反应炔基。并对反应机理进行了探讨。     

联苯醌二亚胺与对苯乙炔共聚物的合成及表征

以PdCl2(PPh3)2/CuI为催化剂,分别通过N,N′-二氯联苯醌二亚胺和3,3′-二甲基-N,N'-二氯联苯醌二亚胺与1,4-二炔基-2,5-二癸氧基苯共聚,得到共轭聚合物聚[联苯醌二亚胺-co-2,5-二癸氧基-1,4-苯撑乙炔](PBz-PPE)和聚[3,3′-二甲基联苯醌二亚胺-co-2,5-二癸氧基-1,4-苯撑乙炔](PDMBz-PPE)。采用红外光谱(FT-IR)、核磁共振(1H-NMR)、凝胶渗透色谱(GPC)、紫外-可见光谱仪(UV-Vis)等测试手段对共聚物的化学结构和性能进行表征。结果表明,在四氢呋喃和三氟乙酸溶液中,此类共聚物的紫外-可见最大吸收峰分别为410 nm和540 nm;在四氢呋喃中荧光发射峰均为485 nm;相对分子质量均在10000左右;通过循环伏安测试得知,本征态的2种共聚物均有1对氧化还原峰(分别为Epa=0.51 V,Epc=0.41 V和Epa=0.48 V,Epc=0.30 V),经碘掺杂以后2种共聚物的电化学活性均有明显提高,且有2对氧化还原峰。     

氯化锌催化合成含硅芳炔树脂

以二乙炔基苯、双(二甲氨基)二甲基硅烷为原料,乙腈为溶剂,通过氯化锌催化实现单步硅烷化合成含硅芳炔树脂。研究结果表明,乙腈做溶剂,二乙炔基苯与双(二甲氨基)二甲基硅烷投料比为9∶8(摩尔比),ZnCl_2相对于炔过量0.65倍,回流反应11h效果最佳,收率高达90%以上;制备的含硅芳炔树脂在室温下呈流动状态,加工性能良好,加工温度为40~180℃,加工窗口为140℃;固化后的含硅芳炔树脂,在N_2气氛下热分解5%时的温度(T_(d5))为587℃。     

聚(苯基硅烷-芳炔)树脂合成及耐高温结构形成机理

含硅芳炔树脂(PSAs)因其突出的耐热性能,在诸多领域具有应用价值.为满足高速发展的航空航天、电子信息技术的应用需求,耐高温树脂材料性能亟待提升.本研究以1,3-二乙炔基苯和苯基二氯硅烷为原料,通过格氏试剂法合成线型聚(苯基硅烷-芳炔)树脂(PPSA),对其交联固化形成耐高温结构的机理进行研究.采用差示扫描量热仪(DS...     

聚(二乙炔基苯-硅烷-硼烷)树脂的合成及性能

从分子结构设计出发,采用二乙炔基苯、苯基二氯硼烷和甲基氢二氯硅烷为主要原料,采用格氏试剂法合成了一种耐高温硼硅炔有机-无机杂化树脂聚(二乙炔基苯-硅烷-硼烷)(PASB)。采用FT-IR、1H-NMR、13C-NMR和GPC对其结构进行了表征,利用DSC和TGA研究了聚合物的固化反应行为和耐热性能,讨论了结构中不同硅硼含量与产物性能之间的依赖关系。结果表明,PASB树脂常温下黏度适中,可以在较低的温度下发生固化交联反应,具有良好的加工性能。其固化物具有良好的耐热性,在N2气氛下失重5%时的温度(Td5)均高于600℃,1000℃的质量保留率大于85%。     

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.     

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     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to