填料对双组分有机硅密封胶性能的影响

Impact of Fillers on Performance of Two-component Silicone Sealant

研究了填料对双组分有机硅密封胶力学性能的影响。通过改变填料的种类,制备了不同性能的有机硅密封胶,并测试其在不同条件下处理后的拉伸强度和拉断伸长率。结果表明,不同填料对有机硅密封胶性能影响不同,标准条件下密封胶拉伸强度和拉断伸长率都不同;以钛白粉、滑石粉、石英粉为填料,熔融温度高、热膨胀系数小,200℃高温环境后,加入这些填料制成的密封胶拉伸强度与标况下强度比值分别为88%、80%、78%;采用H2SO4质量分数为5%、10%、40%的H2SO4溶液浸泡后,以石英粉为填料制成的密封胶拉伸强度与标况下强度比值最高;以碳酸钙为填料制成的密封胶在200℃高温和3种质量分数的硫酸溶液浸泡后密封胶的拉伸强度和拉断伸长率降低较多;6种填料制成的有机硅密封胶耐盐雾侵蚀的能力差别不大,经盐雾环境处理1 000 h后,密封胶拉伸强度与标况下强度比值均在90%以上。

The impacts of fillers on mechanical performance of two-component silicone sealant were stud-ied.By changing the types of fillers, different silicone sealants with various properties were prepared, and then their tensile strength and tensile elongation tested under different conditions.Results show that different fillers impact differently on the properties of silicone sealant.Under the standard conditions, tensile strength and tensile elongation of the sealants are different.illers of titanium dioxide, talcum powder and quartz powder have a high melting temperature and small thermal expansion coefficient.After 200 ℃ reaction, the tensile strength and the strength ratio under standard conditions are 88%, 80%and 88%respectively.With the mass fraction of 5%, 10%and 40%of the sulfuric acid solution, the tensile strength and the strength ratio of the sealant made by quartz powder are the highest under standard conditions.Sealant made by calcium carbonate at 200℃, the tensile strength and tensile elongation of the sealant soaking in 3 kinds of mass fraction of sulfu-ric acid solution decrease more siginificantly.The salt fog resistance of silicone sealants made by 6 kinds of filler have no difference, but after 1000 h salt spray treatment, the tensile strength of sealant is still above 90%, compare with the standard conditions.