Effect of Vulcanization Temperature on Properties of Ceramifiable Silicone Rubber and Its Ceramic Bulk

Ceramifiable silicone rubber materials are fabricated using methyl vinyl silicone rubber, muscovite, glass powder and 2,4-dichloro-benzoyl peroxide (DCBP). The effect of the various vulcanization temperature from 110 °C to 130 °C on the ceramifiable silicone rubber and its ceramic bulk was investigated. It is found that the electrical and mechanical performances of ceramifiable silicone rubber are greatly improved when the vulcanization temperature is set at 120 °C. The volume resistivity of the ceramifiable silicone rubber can be enhanced to 6.71×10
¹⁴
Ω•cm, while dielectric constant and loss tan are reduced to 4.3 and 0.025, respectively. The tensile strength of the ceramifiable silicone rubber can be elevated to 6.5 MPa, which is 20.8% higher than that vulcanized at 110 °C and 130 °C. In addition, the flat insulation ceramic bulk can be obtained by sintering the ceramifiable silicone rubber at 950 °C. The linear shrinkage reaches 23.75% and the three-point bending strength goes up to 111.86 MPa, which is more than 5 times higher than the reported values. Therefore, an appropriate vulcanization temperature is crucial to achieve the optimal performance of the ceramifiable silicone rubber and the ceramic bulk after sintering.