含氟热塑性硫化胶

该项发明主要涉及由氟代烃组成的热塑性硫化胶(TPV)，它能解决诸如合成时TPV易粉化、熔融加工性能差和物理机械性能低下，不能承受后硫化加工等问题。解决这些问题无需借助于经化学改性的标准商品化氟弹性体，或不用具有特别硫化点的单体组分生产氟弹性体。该热塑性硫化胶由氟化的聚合物两相组成，它有优异的机械性能、耐热性和耐油性(包括在舍碱的油中)及易熔融加工性。此外，文中还介绍了它的生产过程。业已发现，可以通过应用氟弹性体组分获得两相组成，即二种和更多种氟弹性体的共混物，其中，至少有一种是亚乙烯基二氟／四氟乙烯／丙烯三元共聚的氟弹性体。     

液体氟弹性体/固体氟橡胶复合材料的制备与性能研究

制备液体氟弹性体/固体氟橡胶复合材料,并研究液体氟弹性体/固体氟弹性体用量比（简称液固比）对复合材料性能的影响。结果表明：与固体氟橡胶相比,液体氟弹性体/固体氟橡胶复合材料的加工性能明显提高,物理性能、耐热性能、耐油性能和阻尼性能略有降低,但变化不大;液固比为5/95的复合材料综合性能较好。     

液体氟弹性体的合成和表征

通过对液体氟弹性体(低分子量氟弹性体)的分子量及其分布、共聚单体组成和微观结构的分析，发现二溴四氟乙烷对于液体氟弹性体的聚合反应具有明显的分子量调节作用，同时研究了液体氟弹性体聚合物的端基组成和序列结构。     

可用过氧化物硫化的氟弹性体

在汽车和航空各工业部门大量使用弹性体制造高质量密封和胶管，胶管中充有不同的气体或液体。在许多情况下，由于工作温度高或要求耐化学性好，多选用氟弹性体。汽车工业大量使用密封件，要求产品质量与生产经济性取得平衡。粘模和结垢使装模和挤出加工困难，会造成密封和胶管表面质量问题。除要求加工容易外，还要求产品在长期使用中性能可靠。基于2001年开发的新型结构聚合物，通过对主键分子结构重新设计及新链段终止和交联点化学调整，获得新型氟弹性体。本文介绍几种新型可用过氧化物硫化的低粘度氟弹性体，设计用于模型加工较难的产品使之容易加工，且有很好的性能。     

新型氟弹性体在航空密封领域内的应用进展（上）

半个世纪以来，Viton氟弹性体被成功应用在苛刻的宇航领域中。极端的高温与低温是飞行过程的固有特性。文中讨论的几种过氧化物硫化新型氟弹性体，其工作温度-45℃～＋275℃，工作介质为空气、润滑油、标准参比油等。这些新型氟弹性体均采用APA技术合成，经过各种试验后发现，其具有更高的使用性能、更好的加工性能，能满足制造高品质航空密封件的需要。     

Viton氟弹性体系列专题讲座（四）：新型氟弹性体在航空密封领域内的应用进展（下）

半个世纪以来，Viton氟弹性体被成功应用在苛刻的宇航领域中。极端的高温与低温是飞行过程的固有特性。文中讨论的几种过氧化物硫化新型氟弹性体，其工作温度-45℃-＋275℃，工作介质为空气、润滑油、标准参比油等。这些新型氟弹性体均采用APA技术合成，经过各种试验后发现，其具有更高的使用性能、更好的加工性能，能满足制造高品质航空密封件的需要。     

AGC化学公司推出AFLAS氟弹性体

AGC化学美国公司以Fluon和AFLAS品牌生产和销售高性能氟弹性体产品。不久前，该公司推出了四氟乙烯和丙烯共聚AFLAS氟弹性体。该公司称，这一组合使AFLAS氟弹性体独特的性能超越了常规的FKM型氟弹性体，满足了油／气、化工、线缆、重型设备、食品加工和医药以及汽车工业的使用要求。     

VDF、PVDF国内外市场及技术进展

VDF是含氟烯烃的重要品种之一，主要用作合成高分子材料的单体。在氟弹性体方面，VDF是最主要的单体，几乎所有的氟弹性体中都含有VDF组分。     

国外动态

国外动态信越化学开发液体氟弹性体日本信越化学公司开发了新型液体氟弹性体（ＳＨＩＮ－ＥＴＳＵＳＩＦＥＬ系列）并已商品化。这是一种主链含有全氟醚结构ＧＦ－ＣＦ－Ｏ,可在１５０℃加热,且具ＣＦ３有优良耐油、耐溶剂、耐低温性的氟橡胶。这种液态弹性体是以氟单体...     

橡胶加工商-Nordel

美国 Ｎｏｒｄｅｌ　 ＩＰ公司可根据制造商要求，加工各种烃类橡胶。该公司还加工　Ｖｉｔｏｎ Ｅｘｔｒｅｍｅ、Ｖｉｔｏｎ ＥＴＰ－５００和 Ｖｉｔｏｎ ＥＴＰ－９００等氟橡胶品级。据介绍这些优质氟弹性体显示有最宽的氟弹性体耐流体范围，同时保持Ｄｕ Ｐｏｎｔ Ｄｏｗ弹性体公司原先Ｖｉｔｏｎ品级同样的高温性能。橡胶加工商-Nordel@任伟成     

高性能有机氟材料制备科学及应用进展

有机氟材料具有优异的热氧稳定性、耐化学腐蚀性、耐老化性、不黏性、电绝缘性以及极小的摩擦系数等特性,因此作为一种不可替代的材料广泛应用于高新技术产业。近年来高新技术产业发展对高性能有机氟材料的需求引发了学术界和工业界对氟材料的研究兴趣。依据本文作者的研究经历及有机氟材料的发展方向,本文介绍了氟树脂（新型含氟聚合物、电活性含氟聚合物、新型全氟磺酸聚合物、聚四氟乙烯3D打印）及氟橡胶（过氧化物硫化氟橡胶、耐低温氟醚橡胶、耐高温全氟醚橡胶、全氟聚醚基类玻璃橡胶）的制备科学及应用进展,特别阐述为了满足航空航天、能源、信息等高新技术产业需求发展的新一代高性能有机氟材料。本文也介绍了近期出现的聚四氟乙烯新成型技术及类玻璃氟橡胶。文章指出发展绿色环保和高效的高性能有机氟材料制备及成型加工方法是今后的发展方向。     

氟橡胶的并用改性研究进展

氟橡胶的特殊性能是由其分子中固有的氟原子结构特点所决定的,但氟橡胶也存在不足之处,如弹性差、撕裂强度低、耐低温性能欠佳、易压缩变形、生胶加工性能差等。为了提高氟橡胶及其制品的性能,国内外学者对氟橡胶进行了大量的改性研究工作,包括主链改性、并用改性、填充改性和表面改性等,其中并用改性具有工艺简单、成本低廉、易于推广等优点,是开发高分子材料新品种的重要途径。本文详细综述了目前氟橡胶并用改性的研究状况。     

氟橡胶耐热氧老化性能的研究

研究炭黑N330/N990用量比对过氧化物硫化体系氟橡胶物理性能和耐热氧老化性能的影响,并与双酚A硫化体系氟橡胶进行比较。结果表明:随着炭黑N330/N990用量比增大,过氧化物硫化体系氟橡胶的物理性能和耐热氧老化性能提高,压缩永久变形明显减小;当炭黑N330/N990用量比较大时,氟橡胶的物理性能变化不大;与双酚A硫化体系氟橡胶相比,过氧化物硫化体系氟橡胶的硬度和定伸应力较小,拉伸强度和拉断伸长率较大,耐热氧老化性能较好。     

Role of processing aids in the extrusion of molten polymers

Product quality and, in general, processing windows and rates of production in the extrusion of molten polymers are limited by various flow instabilities (mainly melt fracture) that are observed at high production rates. While there still are unresolved issues in comprehending these phenomena, industry demands for process optimization dictate the employment of processing aids (PAs) for product quality improvement and energy requirement reduction. In this review paper, most commercially used processing aids (PAs) are discussed, namely, fluoroelastomers, stearates, small amounts of polymers blended with the process polymer, and the newly discovered boron nitride as pure and in combination with other fluoroelastomers. This paper focuses on the appropriate and optimum usage of the various PAs as well as on the mechanism that underlies their action for flow enhancement and instability elimination. Finally, numerous experimental observations are discussed, and several examples are illustrated.     

氟橡胶及硫化机理概述

介绍了氟橡胶的主要种类及特点、常用的4种硫化体系和硫化机理,分析了有机二胺类、双酚类、有机过氧化物类及辐射交联类硫化体系的优缺点及其对硫化胶性能的影响,指出了双酚类硫化体系是目前常用的硫化体系,认为有机过氧化物类硫化体系可为氟橡胶带来优异的性能.     

Communication: Autoignition temperatures of carbon-filled fluoroelastomers at elevated oxygen pressure

The autoignition temperature and composition of 15 carbon-filled fluoroelastomers have been determined. These experimental data and three sets of literature data are used to examine the relationship between autoignition temperature and rubber composition. The autoignition temperature at an elevated oxygen pressure is strongly affected by the carbon black content in rubbers. An empirical equation is derived and can be used to predict the autoignition temperature of carbon-filled fluoroelastomers based on the carbon black content.     

Correlating mechanical and electrical properties of filler‐loaded polyurethane fluoroelastomers: The influence of carbon black

The dynamic mechanical properties and electrical conductivity of a class of polyurethane fluoroelastomers filled with different carbon black types and loadings were investigated. In particular, finely structured and coarsely structured carbon blacks were considered. Dynamic mechanical analysis (DMA) on the unfilled fluoroelastomer confirmed the phase‐segregated nature of this copolymer. The dynamic mechanical behavior of elastomeric compounds reinforced with finely structured carbon black was found to be strongly influenced by the filler content above a threshold value. This behavior may be attributed to the formation of carbon black aggregates and three‐dimensional anisotropic structures at increasing filler loading. Such an effect was not observed in compounds filled with coarsely structured carbon black particles, which do not seem to form higher level structures. These observations were supported by calculations on the hydrodynamic effect of the filler on the storage modulus G′ of carbon black–loaded compounds. Electrochemical impedance spectroscopy measurements on filled fluoroelastomers revealed the presence of an electrical percolation threshold for finely structured carbon black–filled compounds that supports the hypothesis of the presence of a three‐dimensional anisotropic network forming at high filler loading. No percolation threshold was found in coarsely structured carbon black–filled compounds in accordance with DMA. These results can provide useful guidelines for the design of high‐performance carbon black–filled polyurethane fluoroelastomers. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

水滑石在氟橡胶中的应用研究

讨论了以水滑石替代氢氧化钙作为碱催化剂的硫化特性,研究了水滑石/氧化钙组合对消除氟橡胶硫化试样气泡的作用。研究了水滑石对双酚硫化氟橡胶的耐水性能的影响。     

Poly(fluoroalkoxyphosphazenes)—versatile seal materials

Poly(fluoroalkoxyphosphazene) fluoroelastomers are members of a new family of polymers based on a phosphorous–nitrogen backbone. Physical property evaluation tests have demonstrated that these fluorelastomers possess excellent stress–strain properties, low-temperature flexibility, thermal stability, and resistance to a variety of demanding environments including synthetic lubricants, hydrocarbon fuels, and aqueous caustics. Their service temperature range is about ?60° ?200°C. Poly(fluoroalkoxyphosphazene) fluoroelastomers have shown the capability to function in severe dynamic applications; i.e., lip seals (1? in. I.D.) performed for >1000 hr at 5500 rpm in MIL L-7808G lubricant at 115°C. Also, O-ring seals successfully completed a 1000-hr dynamic qualification test over a temperature range of ?54°–163°C in a rod seal test apparatus. These elastomers can be used for seals, O-rings, gaskets, diaphragms, hose, and protective coatings.     

Thermal stability of some heat-resistant elastomers

The thermal stabilities of four fluoroelastomers, a polyphosphazene elastomer and four polysiloxanes, mainly in the vulcanised state, have been compared by isothermal weight loss experiments in nitrogen, or in air. The overall activation energies for degradation as a function of percentage conversion to volatiles have also been determined. In the majority of cases there was a linear relationship between activation energy and percentage conversion but the slope may be positive, negative or zero.