Rubber gas permeability (air-tightness): gas permeabilities rubber is the product of solubility and diffusivity of the gas in the rubber. Solubility of gases increases with the solubility parameter of the rubber decreases, depending on the number of gas molecules in the rubber in the rubber side groups in the rate of diffusion. Gas in a variety of rubber are very different permeation rate in the rubber gas permeability is low polyether rubber and butyl rubber, butyl rubber, natural rubber air permeability of only 1/20. Rubber gas permeability with increasing temperature rises rapidly, the filler product is for use as a carbon black, the species and quantity of filling gas permeability has little performance impact.

    Flammability rubber: Most rubbers having different degrees of combustibility. The halogen-containing rubber molecules such as chloroprene rubber, fluorine rubber or the like, with some of the fire resistance. Therefore, neoprene and chlorosulfonated polyethylene containing chlorine atom in the external flame is removed, even if the combustion is difficult, and fluorine rubber is entirely self-extinguishing.

    Electrical properties of rubber: General rubber is an excellent electrical insulator, natural rubber, butyl rubber, ethylene propylene rubber and styrene butadiene rubber have very good dielectric properties, it is widely used in cable insulation and so on. Nitrile rubber and chloroprene rubber, because of the presence of a polar molecule, atom or group of atoms, its dielectric properties are poor. On the other hand, in the rubber with the conductive carbon black or conductive metal powder filler, it will have sufficient conductivity to disperse the static charge, or even to become a conductor.