氧化铈对双组分室温硫化硅橡胶耐热性能的影响

Effect of cerium oxide on thermostability of two-component room temperature vulcanized silicone rubber

以二月桂酸二丁基锡为促进剂、正硅酸乙酯为硫化剂、白炭黑和氧化铈为填料制备双组分室温硫化硅橡胶,研究了氧化铈用量对双组分室温硫化硅橡胶耐热性能的影响。结果表明,氧化铈能明显提高双组分室温硫化硅橡胶的耐热性能,且其用量为8份(质量,下同)时耐热效果较好。在250℃下经72 h热空气老化后,添加了8份氧化铈的双组分室温硫化硅橡胶拉伸强度和扯断伸长率的损失率都最小。添加6份氧化铈的双组分室温硫化硅橡胶的热分解温度较未添加者提高了25.5℃,氧化铈在400～510℃时抑制了硅橡胶的热失重行为。

The two-component room temperature vulcanized silicone rubber were prepared with dibu- tyltin dilaurate as accelerator, tetraethyl orthosilicate as curing agent, silica and cerium oxide as filler. The effect of amount of cerium oxide on thermal per- formance of two-component room temperature vul- canized silicone rubber was investigated. The results showed that the cerium oxide could significantly im- prove the thermostability of two-component room temperature vulcanized silicone rubber, and the im- provement of thermostahility tended to the best at 8 phr cerium oxide. After aging at 250 ℃ for 72 h, the loss rate of tensile strength and elongation atbreak of the two-component room temperature vul- canized silicone rubber filled with 8 phr cerium ox- ide reached the minimum. The thermal decomposi- tion temperature of the two-component room temper- ature vulcanized silicone rubber filled with 6 phr ce- rium oxide was 25.5 ℃ higher than that of unfilled, and the cerium oxide inhibited the mass loss of two- component room temperature vulcanized silicone rub- ber at 400 -510 ℃.