Abstract:

Novel green and environment-friendly catalyst have always been the research hotspot of room temperature vulcanized (RTV) silicone rubber owing to the toxicity and high cost of their traditional tin- and platinum-based catalysts. In this paper, a novel organic guanidine catalyst was designed and synthesized from n-butamine and dicyclohexyl carbon diimide (DCC), and the product was utilized to catalyze dehydro-type RTV silicone rubber. The effect of dosage of catalyst, crosslinker and filler on silicone rubber performance was explored. Compared with dibutyltin dilaurate, when the active period was basically consistent, the amount of organic guanformine catalyst was lower, about one third of the amount of organic tin, and the non-adhesive period of the organic guanformine catalytic system was shorter,which implied shorter complete vulcanization time under the same operating time. The organic guanidine catalytic system owned excellent tensile property with a tensile strength of 1.92MPa and an elongation at break of 1117%. The degradation behavior of the organic guanidine catalytic system was studied at room temperature. The results showed that the stronger the polarity of the solvent, the higher the degradation rate of silicone vulcanizates up to 52% in ethyl acetate, which made the use of organic guanidine catalytic silicone rubber in the removable bonding field to be expected.

Key words: silicon rubber, dehydrogenation condensation, catalyst, preparation, degradation

摘要：

由于有机锡、铂金催化剂具有毒性且价格昂贵，新型绿色环保催化体系一直是室温硫化（RTV）硅橡胶的研究热点。本文以正丁胺和二环己基碳二亚胺为原料，通过亲核加成反应设计合成了一种新型有机胍催化剂，并用于脱氢型RTV硅橡胶的催化。探究了催化剂用量、交联剂用量、填料用量对硅橡胶性能的影响，与传统的二月桂酸二丁基锡相比，在活性期基本一致时，有机胍催化剂的用量更低，约为有机锡用量的1/3，并且有机胍催化体系的不粘期更短，这意味着在相同操作时间的条件下具有更短的完全硫化时间，具有很好的实用价值。有机胍催化体系经配方优化后具有优异的拉伸性能，拉伸强度为1.92MPa，断裂伸长率为1117%。有机胍催化体系室温降解研究表明，溶剂的极性越强，硫化硅橡胶降解率越高，在乙酸乙酯中可达52%，这使得有机胍催化硅橡胶有望用于可拆卸粘接领域。

关键词: 硅橡胶, 脱氢缩合, 催化剂, 制备, 降解