机械剪切再生热硫化硅橡胶的结构和性能

Structure and Properties of Thermal Vulcanized Silicone Rubber Recycled by Mechanical Shearing

考察了机械剪切法制备的再生硅橡胶的结构和性能,采用FTIR、SEM、DMA表征了再生硅橡胶硫化胶和新硅橡胶硫化胶的结构,研究了硫化剂DBPMH和沉淀法白炭黑对再生硅橡胶力学性能的影响,以及沉淀法白炭黑对再生硅橡胶透光性的影响。结果表明,硅橡胶再生前后其化学结构没有明显变化,但分子链变短,且再生硅橡胶硫化胶中有明显的白炭黑团聚现象。硫化剂DBPMH用量增大会缩短再生硅橡胶的焦烧时间和正硫化时间,提高力学性能,二段硫化对进一步提升再生硅橡胶的力学性能效果明显。当沉淀法白炭黑用量为15份时,再生硅橡胶硫化胶的力学性能较好。随着沉淀法白炭黑用量的增大,再生硅橡胶硫化胶的透光性先提高后降低,当沉淀法白炭黑用量为15份时,再生硅橡胶硫化胶的透光性最好。

The structure and properties of silicone rubber recycled by mechanical shearing and fresh silicone rubber were characterized by FTIR,SEM and DMA analysis.The effect of curing agent DBPMH and precipitated silica on the mechanical properties of recycled silicone rubber were investigated and the effect of precipitated silica on the transmittance of recycled silicone rubber was studied.The results showed that the chemical structure of silicone rubber did not change significantly before and after the regeneration,but the molecular chain became shorter,and much agglomeration of precipitated silica appeared in the recycled silicone rubber vulcanizates.T10 and T90 of recycled silicone rubber would be shorten and the mechanical properties were significantly improved with the increasing dosage of curing agent DBPMH and the mechanical properties of recycled silicone rubber were further improved by post curing.When the dosage of precipitated silica was 15 phr,the mechanical properties of recycled silicone rubber was better.The light transmittance of recycled silicone rubber vulcanizates first increased and then decreased with the increasing of the amount of precipitated silica and light transmittance was the highest with the addition of 15 phr precipitated silica.