耐热添加剂对硅橡胶硫化胶耐热老化性能的影响

从硅橡胶硫化胶热老化机理出发,提高硅橡胶硫化胶耐热老化性能的方法主要有以下几种：①改变硅橡胶侧链基团的结构,如引入苯基等,以防止硅橡胶由于侧链基团氧化分解而引起分子主链的交联或降解;②在硅橡胶分子主链中引入大体积链段,如碳十硼烷基、亚苯基、亚苯醚基和...     

耐热硅橡胶的研究进展

本文较详细地综述了国内外耐热硅橡胶的研究情况。     

耐热硅橡胶粘合剂技术进展

综述国内外耐热硅橡胶粘合剂的技术进展情况。     

热硫化型氟硅橡胶胶粘剂的耐热性能

研究了氟硅橡胶胶粘剂的热空气老化性能和高温粘接性能，结果表明，该胶粘剂用于氟硅橡胶与不同金属的热硫化粘接时，具有良好的耐热空气老化性能和高温粘接性能。     

双组分室温硫化硅橡胶耐热性能的研究进展

讨论了双组分室温硫化硅橡胶的耐热性能,介绍了其热氧老化机理,并分析了提高耐热性能的途径,主要包括:改变其主链与侧基的结构,消除硅羟基,使用新型硫化体系,加入硅氮类化合物、耐热添加剂和硅树脂等。     

热重分析表征硅橡胶的耐热性

通过二组共八个硫化的乙烯基硅橡胶样品的热重分析数据与热空气老化结果的比较，说明热重分析在筛选耐热添加剂方面的应用。     

脱氢型室温硫化硅橡胶耐高温及热老化性能研究

借助热失重和热老化试验方法考察了硅橡胶种类、催化剂种类、含氢硅油用量和填料种类对脱氢型室温硫化(RTV)硅橡胶耐热性能的影响.结果表明:硅橡胶、催化刺、含氢硅油和填料对脱氢型RTV硅橡胶耐热性均有显著影响.较佳的配方是:100份硅橡胶,1份催化剂,2份含氢硅油,30份填料.     

硅橡胶／铁氧体复合材料耐热空气老化性的研究

研究了室温硫化硅橡胶／锰锌铁氧体复合材料耐热空气老化性能。结果表明：经200℃×12d老化后，试样的拉伸强度、邵尔A硬度和定伸应力均明显下降；但拉断伸长率明显提高。体积电阻率、表面电阻率以及介电强度都有所下降；不同频率下的复介电常数和损耗因子星上升趋势。通过对老化前后材料交联密度的测试，可以认为造成上述结果的主要原因是硅橡胶受热降解。     

缩合型RTV硅橡胶耐高温性研究进展

介绍了缩合型室温硫化(RTV)硅橡胶的热老化机理,综述了提高缩合型RTV硅橡胶耐热性的主要方法:改变主链和侧基结构、使用新型硫化交联体系、加入添加剂以及其它方法,并指出了提高缩合型RTV硅橡胶耐热性的研究发展方向。     

室温硫化硅橡胶耐热性的研究进展

介绍了硅橡胶的热氧老化机理及室温硫化硅橡胶耐热性的研究进展,综述了提高室温硫化硅橡胶耐热性的主要途径:改变聚硅氧烷主链和侧基的结构、采用新型硫化体系、添加耐热添加剂、添加硅氮类化合物等,指出了提高室温硫化硅橡胶耐热性的发展方向。     

加成型硅橡胶的研究进展

综述了近年来加成型硅橡胶在高强度、高耐热、加成注射成型等方面的研究进展。     

导热硅橡胶的研究进展

综述了填充型导热橡胶的导热机理和各类导热填料的导热特性,介绍了提高导热硅橡胶导热性的途径。     

高性能多功能硅橡胶的研究

介绍了耐３５０℃室温和高温硫经硅橡胶、高导热兼耐高温和高粘合强度室温硫化硅橡胶、耐油兼耐高温硅橡胶和空间及硅橡胶的研制情况,并与国内外同类产品进行对比。４种硅橡胶性能均达到了目前国际先进水平。     

自然老化对导电硅橡胶电阻特性的影响

分析了异电硅橡胶的电阻性特自然老化条件下的变化规律,发现自然老化对导电硅橡胶电阻行性的影响与导电粒子的质量分数有关,并确定了最佳的导电粒子质量分数。     

导热室温硫化硅橡胶的研究进展

介绍了导热室温硫化硅橡胶的导热机理及导热模型,分析了室温硫化硅橡胶的导热性能及综合性能,并概述了国内外导热室温硫化硅橡胶的研究现状。指出通过填充不同粒径分布的填料或对填料进行适当的表面处理,可以制备高导热室温硫化硅橡胶。     

加成型液体硅橡胶

介绍了加成型液体橡胶的硫化机理,组成及应用。     

Thermal stability and ablation properties of silicone rubber composites

Effects of incorporation of clay and carbon fiber (CF) into a high temperature vulcanized (HTV) silicone rubber, i.e., poly(dimethylsiloxane) (PDMS) containing vinyl groups, on its thermal stability and ablation properties were explored through thermogravimetric analyses (TGA) and oxy‐acetylene torch tests. Natural clay, sodium montmorillonite (MMT), was modified with a silane compound bearing tetra sulfide (TS) groups to prepare MMTS₄: the TS groups may react with the vinyl groups of HTV and enhance the interfacial interaction between the clay and HTV. MMTS₄ layers were better dispersed than MMT layers in the respective composites with exfoliated/intercalated coexisting morphology. According to TGA results and to the insulation index, the HTV/MMTS₄ composite was more thermally stable than HTV/MMT. However, addition of CF to the composites lowered their thermal stability, because of the high thermal conductivity of CF. The time elapsed for the composite specimen, loaded with a constant weight, to break off after the oxy‐acetylene flame bursts onto the surface of the specimen was employed as an index for an integrated assessment of the ablation properties, simultaneously taking into consideration the mechanical strength of the char and the rate of decomposition. The elapsed time increased in the order of: HTV < HTV/CF ≈ HTV/MMTS₄ < HTV/CF/MMTS₄ ≈ HTV/MMT < HTV/CF/MMT. This order was different from the increasing order of the thermal stability determined by TGA results and the insulation index. The decreased degree of crosslinking of the composites with MMTS₄ compared with that of the composite with MMT may be unfavorable for the formation of a mechanically strong char and could lead to early rupture of the HTV/MMTS₄ specimen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

A comparison of ablative resistance properties of liquid silicone rubber composites filled with different fibers

Flexible ablative materials play a key role in thermal protection systems to protect space vehicles during hypersonic flight missions. In this work, epoxy resin modified liquid silicone rubber was adopted as elastomeric matrix. Two inorganic fibers (carbon fibers (CF) and quartz fibers (QF)) and two organic fibers (aramid fibers (AF) and poly (p-phenylene benzobisoxazole) fibers (PBO)) were chosen as functional fillers. The ablation resistance and thermal insulation properties were evaluated using oxyacetylene torch test. Microstructure and phase composition of the char layer was fully characterized to investigate the ablation mechanism. SEM observations revealed that the fibers are well dispersed and integrated in the matrix. TGA analysis indicated that the inorganic fibers possess significantly higher thermal stability than organic fibers. In addition, a molten silica film can be formed on the material surface, which can exert a better thermal protection effect on the matrix. Furthermore, the ablation test shows that the linear ablation rate decreases first and then increases with an increase of fiber content. This work provides basic data to guide optimal selection of fibrous ablatives to enhance ablation performance.