Abstract: Compostible compositions in the form of homogeneous mixtures containing 20-80% by weight unvulcanized, uncured C4-C6 alkadiene elastomer, e.g., natural rubber, 5-20% of modifier, e.g., casein, dextrose, starch or mixtures thereof, 1-40% filler, e.g., titanium dioxide or fibrous clay, 0-30% wax, e.g., carnauba wax, 0-40% styrene resin, e.g., polystyrene, 0-10% additive, e.g., bis-steramide, and 0-20% yeast are disclosed. Preferably such compositions are prepared as aqueous dispersions that can be converted by conventional casting procedures into thin sheets, e.g., about 1 to 10 mils, having useful tensile strength, elongation, flexibility and moisture barrier properties.

Abstract: A one-part composition for application to a substrate, e.g., automotive metal body panels, to provide reinforcement thereto is a thixotropic admixture containing as essential components (a) a heat curable epoxy resin system including the reaction product in the presence of a catalyst of at least one epoxy resin with a carboxy terminated elastomer, (b) dicyandiamide, and (c) a plurality of inorganic particulate filler materials, at least one of which is capable of imparting thixotropic properties to the composition. The method of reinforcing the substrate involves spraying the one-part epoxy resin containing composition onto at least a portion thereof in a heated condition and thereafter curing the composition at a temperature higher than the spraying temperature. Resulting reinforced substrates have tenaciously adhered thereto on at least a portion of one surface thereof a thermoset layer formed by the hot spraying and then curing thereon of the thixotropic composition.