Extruded conductive silicone rubber with high compression recovery and good aging‐resistance for electromagnetic shielding applications

Present conductive silicone rubber with carbon blacks has low compression recovery, and is difficult to make long‐term electromagnetic shielding products. In order to solve the problem, special hollow‐shell carbon blacks were used and then treated by coupling agent to prepare conductive silicone rubber. The compression set of conductive rubber at 100°C for 48 h was only 8.9%, displaying a extremely good recovery. Importantly, the special rubber can be extruded and then continuously vulcanized. Moreover, its electromagnetic shielding effectiveness reached beyond 20 dB at the frequency of 0.01 MHz–10 GHz. After the thermal oxidative aging at 90 and 110°C for 30 days, carbon blacks occurred to aggregate, which gives rise to a drop of tensile property and slight effects on the modulus and hardness. The compression set also increased, but it still maintained a low level after 30 days. There is only little change for the conductivity of silicone rubber and thus its electromagnetic shielding effectiveness still retained beyond 20 dB, showing a good aging resistance. It is believed that our findings may provide an effective solution to fabricate rubber products to sever the electromagnetic protection. POLYM. COMPOS., 40:1078–1086, 2019. © 2018 Society of Plastics Engineers