Abstract: An elastomer barrier composition comprises a melt blend of syndiotactic 1,2-polybutadiene, a terpolymer of ethylene, vinyl acetate and vinyl alcohol, and a compatibilizing agent. The melt blend is formed under suitable mixing and shear conditions such that the terpolymer exists as a separate domain in generally a flat or plate-like form. The elastomer barrier material can be utilized in rubber compositions such as in the innerliner of the tire.
Abstract: Novel polysiloxane-silazane preceramic polymer compositions are prepared by the controlled hydrolysis polymerization of a trimer or tetramer of a monomer of the structure ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently alkyl groups containing from 1 to 4 carbon atoms, R.sup.a, R.sup.b, R.sup.c, and R.sup.d are independently alkenyl or alkyl groups containing from 2 to 6 carbon atoms with the proviso that at least one of R.sup.a, R.sup.b, R.sup.c, or R.sup.d group is an alkenyl group. The polysiloxane-silazane polymers are cured by heat and optionally free radical initiators such as various peroxides. The cured preceramic polymers so formed can be u sed in the pyrolyzed or non-pyrolyzed state as adhesives, coatings, binders, fibers, matrix resins, and the like.
Abstract: Cured rubber compositions having reduced nitrosamine content are made with small amounts by weight of an alkaline earth oxide or hydroxide which are utilized in association with secondary amine containing accelerators. The amount of nitrosamine in the cured rubber is often reduced to less than 20 parts per billion.