Abstract: A rubber molding composition comprising cured rubber scrap (as from automobile tires), a liquid, sulfur-curable polymeric binder, and a curing agent for the polymeric binder. The composition employs from about one to about five parts by weight of the polymeric binder per 100 parts by weight of the scrap rubber. The thus treated rubber scrap may be used in large proportions as a filler or extender for uncured rubbers.

Abstract: Pre-expanded styrene polymer particles, which may contain one or more pre-expanded styrene polymer beads, are coated with sufficient water glass so that the particles, when dried to a reversible, tack-free pourable state, comprise from about 30% to 80% styrene polymer solids. The particles may be shaped into a desired article configuration and then dried to a tack-free state, the particles adhering together through the water glass, and the resulting article having a bulk density of from about 1.25 lbs. to 3 lbs. per cubic foot. The water glass or the pourable particles may be treated to decrease alkalinity and to cause irreversible precipitation of water glass solids, rendering the final product essentially waterproof.