硅酸盐无机胶黏剂的粘结和绝缘性能

Bonding and Insulating Properties of Silicate Inorganic Adhesive

制备了不同成分配比的耐高温硅酸盐胶黏剂,用体视显微镜、扫描电镜观察胶体的形貌,用低载荷拉伸试验机测试其粘结力,并分析试样在高温条件下及饱和水蒸汽环境中的绝缘性能。结果表明:随着硅酸盐胶黏剂的液相组分中SiO_2/M_2O模数比变小、固相粉末粒度分布范围变宽及液固相质量比的适当调节,其粘结强度均有较大的提升;胶黏剂绝缘的性能随着温度的升高而恶化并存在绝缘电阻大幅下降的临界温度,碱金属离子含量的增加降低其临界温度并加快其下降趋势;在饱和水蒸气环境中胶黏剂绝缘性能普遍降低,对固化后的胶体进行高温热处理使其绝缘性能有较大提升,但碱金属离子含量和胶体微观裂纹会降低其绝缘性能。

For studying the bonding and insulating properties of inorganic adhesive, different compositions of silicate adhesive samples were prepared in this paper. The morphologies of the solidified adhesives were observed by the microscope and SEM. The bonding force was determined by low-loaded tensile testing machine and the insulation resistance of sample was measured under various temperature and saturated vapor environment. The results indicated that the bonding-strength of sample is greatly improved by the decrescent SiO2/M2O modulus ratio of liquid composition, the wide sizes and distributions of the solid powders as well as the proper ratio between solid and liquid component. The insulating property of sample deteriorates with temperature rising, and sample with more content of alkali metal ion shows lower critical temperature and quicker downtrend. Sample’s insulating resistance obviously decreased when it was under saturated vapor environment, which might be greatly improved by heat treating, but it can also deteriorate by the increase of both alkali ion content and micro crack of adhesive.