耐高温液体改性聚硫橡胶的制备及性能

Preparation and properties of high-temperature resistance modified liquid polysulfide

通过双酚A环氧树脂对液体聚硫橡胶进行化学改性,在液体聚硫橡胶分子结构中引入适量的苯环耐高温链段,制备了可室温硫化的耐高温液体改性聚硫橡胶,并对改性后聚硫橡胶的性能进行了研究。研究结果表明:改性后聚硫橡胶的分子量和黏度略有提高,耐热降解温度可提高10℃以上,但低温性能会有一定程度提高,需合理控制环氧树脂的量。以改性聚硫橡胶为基体的密封剂具有良好的耐高温性能和粘接性能,但随着改性环氧树脂量的增加,密封剂断裂伸长率随之降低,剥离强度呈现先增后降的趋势。

Room temperature vulcanizable,high-temperature resistance modified liquid polysulfide wasprepared by chemical modification of bisphenol A epoxy resin,and benzene ring high-temperature resistancesegments were introduced into the microstructure of polysulfide.The properties of the modified polysulfide were alsostudied.The research results showed that the molecular weight and viscosity of modified polysulfide were slightlyimproved and thermal degradation temperature was improved over 10℃.But the glass transition temperatureincreased to a certain extent,therefore the dosage of epoxy resin should be reasonably controlled.Matrixmodification sealants had good high-temperature resistance and adhesive properties.However,with the increase ofthe amount of bisphenol A epoxy resin,the elongation at break of sealant decreased,and the peel strength increasedfirst and then decreased.