Preparation of fluorosilicone rubber containing perfluorocyclobutyl aryl ether

Abstract

A new curing system for high temperature vulcanized fluorosilicone rubber was studied by thermal cycloaddition reaction of trifluoroethylene aryl ether (TFVE). Fluorosilicone rubber containing perfluorocyclobutyl aryl ether (Si‐PFCB) was prepared by using the polysiloxane containing trifluorovinyl aryl ether (Si‐TFVE) as base gum. The basic formula of vulcanized rubber was determined as: 100 parts Si‐TFVE (0.10%TFVE, mol), 50 parts fumed silica. The curing process is as follows: the primary curing process is 180°C, 25 minutes; the post‐curing process is 190°C, 3 hours. It is found that the mechanical properties (the tensile strength is 6.9 MPa, the tearing strength is 35.3 KN/m and the elongation at break is 1685%), thermal property (Tg: −120 ± 5°C) and heat resistance (T5: 450 ± 5°C) of Si‐PFCB are comparable to ordinary high‐temperature vulcanized silicone rubber, while the new curing system has the advantage of no vulcanizing agents and no by‐products.