我国胶粘剂市场现状及发展态势

阐述了2003~2005年,主要是2005年中国大陆胶粘剂及密封剂的产量、销售额、增长率、进出口量和市场情况,并对2006~2008年的发展态势进行了预测,对原材料供应和能源市场进行了分析。     

燃料电池用密封胶

有机硅橡胶一直以来都用来做燃料电池的密封材料,但有机硅透气性高,不适合氢气、氧气等高透过性气体的密封。三键公司经过多年的潜心研究,成功开发出以聚异丁烯为基材的低透气性密封胶。本文主要介绍燃料电池概念、构造、对密封的要求、泄漏机理以及开发的新型密封胶性能。     

Optimum processing parameters to improve sealing performance in solid oxide fuel cells

Glass–ceramic composites are among the favorable candidates as a sealing material for solid oxide fuel cells (SOFC). In order to obtain a reliable, robust and hermetic sealing, the glass–ceramics must chemically bond to both the metallic interconnector and the ceramic electrolyte. A high-bonding strength and good wetting, which strongly depend on the thermal treatment, are always preferred to ensure gas-tight sealing. The thermal treatment involves three stages: binder burnout (stage-I), sintering (stage-II), and cooling (stage-III). This study investigates effects of various parameters on the sealing quality at the sintering stage. The effects of sintering temperature, clamping pressure and sealant thickness are considered. The glass–ceramic laminates are produced employing a tape casting method. The sealing quality is evaluated by measuring leakage and final macro-structure of the sealing region. It is suggested that a 900–930 °C sintering temperature and 1.5–7.6 N cm⁻² clamping pressure ranges are better for successful sealing. The initial thickness of glass–ceramic laminates is also desired to be between 0.25–0.5 mm thickness range for both a cost-effective and reliable sealing.     

聚氯乙烯密封胶起泡原因分析及对策

聚氯乙烯（PVC）密封胶起泡的三大原因为：胶泵密封不良、换胶操作不当、原料不合格。通过对现场PVC密封胶起泡原因分析,确定起泡原因为操作不当,后续制定严格的操作规范,有效控制密封胶起泡的再次发生。     

航空聚硫密封剂人工热氧加速老化行为研究

对航空聚硫密封剂进行人工加速热氧老化试验,并采用光学显微镜、光泽度仪、邵氏A硬度计、万能试验机、动态力学分析(DMA)法和红外光谱(FT-IR)法等手段分析了热氧老化对聚硫密封剂的表面微观形貌、硬度、拉伸性能、耐热性和基团特征峰等影响。结果表明:随热氧老化时间延长,聚硫密封剂的光泽度逐渐降低,表面出现明显的泡孔缺陷;当老化时间为20~30 d时,密封剂的拉伸强度和断裂伸长率降幅明显;当老化时间为40 d时,聚硫密封剂的硫化反应更加完全,并且老化期间无可降解新官能团生成,而且其耐热性和室温储能模量基本不变,说明其耐热氧老化性能良好。     

纳米碳酸钙二次粒径对有机硅密封胶力学性能的影响

采用X射线衍射仪、扫描电子显微镜、激光粒度分布仪分析了纳米活性碳酸钙的相组成及粒子结构、形貌、粒径分布;研究了几种一次粒径相近、不同二次粒径的纳米活性碳酸钙对脱酮肟型单组分室温硫化(RTV)有机硅密封胶力学性能的影响。结果表明,一次粒径小的碳酸钙,经表面处理后的二次粒径不一定小;二次粒径比一次粒径对RTV有机硅密封胶的力学性能影响更大:随着二次粒径的减小(而非一次粒径的减小),RTV有机硅密封胶的拉伸强度、断裂伸长率和硬度都呈增加趋势。     

高强度聚氨酯粘接密封胶耐湿热性研究

以聚氨酯预聚物、增塑剂、炭黑为主要原料制备出一种高强度挡风玻璃粘接密封胶,该胶耐候性优异,达到了某主机厂的技术要求;重点探讨了聚氨酯预聚物和增塑剂对聚氨酯胶耐湿热性能的影响,研究了预聚物种类对剪切强度的影响。     

增塑剂对聚氨酯密封胶性能的影响

以自制的聚氨酯预聚体为主体原料,配以填料、助剂等配制成单组分湿固化聚氨酯密封胶。讨论了增塑剂对聚氨酯密封胶老化性能的影响,结果显示：当增塑剂与聚氨酯体系的极性相近时,体系的耐迁移性随着增塑剂相对分子质量的增加而增加;当增塑剂与聚氨酯预聚体的相对分子质量相近时,增塑剂的极性与聚氨酯体系越接近,耐老化性能就越优越。通过老化实验表明：增塑剂的相对分子质量对于密封胶的耐紫外性能有一定的抑制作用,湿热是密封胶老化和增塑剂流失的关键原因之一。     

The effect of epoxy resin to reduce the compression set of polysulfide sealant

In this article, modified polysulfide sealants with lower compression set were prepared by a simple method of introducing the diglycidyl ether of bisphenol A resin (DGEBA epoxy resin) into sealants. The investigation on reactivity analysis and gel faction test verified that the incorporation of epoxy resin in sealants was just a blending process rather than copolyaddition with polysulfide resin. Stress–strain behavior during compression revealed that the epoxy resin could reduce the compression stress when the sealants were loaded to a certain strain, which effectively lessened crosslink breakages and benefited to compression resistance. Also the rigid phenyl structure in epoxy resin may retard incidental slide between polysulfide chains and prevent interchange reactions between disulfide linkages. The incorporation of 2 phr epoxy resin distinctly reduced compression set of polysulfide sealant from 28.3% to 11.2% after compressed 25% at 23°C for 1 day. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012