Butyl Rubber Guide
A solid piece of butyl rubber (isobutylene-isoprene rubber, IIR) is a dense, black or dark-gray elastomer known for its very low gas permeability, high dampening, and excellent resistance to weathering, ozone, and chemicals.
Would you like help distinguishing butyl from other rubbers (EPDM, nitrile, neoprene) in solid form? butyl rubber