Abstract: Fiberboard shims are manufactured which contain blocked isocyanates. The blocked isocyanates are blended with the other shim components to ensure complete distribution of the isocyanate into the shim, thereby improving the strength characteristics of the shim while simultaneously simplifying the manufacturing procedure. Further, the need for hazardous solvent-based isocyanates in the workplace is eliminated.

Abstract: A metal rubber gasket includes a central metal lamina sandwiched by two outer elastomer layers. The elastomer is a blend of a butadiene-acrylonitrile rubber and a random terpolymer of ethylene, alkyl acrylate and the mono alkyl ester of a dioic acid. Preferably the butadiene-acrylonitrile rubber is functionally modified with polar groups such as a carboxyl, amine, or hydroxyl groups.

Abstract: A solventless prepolymer which is liquid at room temperature and cures at about 350.degree. F. The novel prepolymer is formed from a rubber monomer; acrylonitrile or methacrylonitrile; and an ether derivative of methylol acrylamide. The ether is formed from methylol acrylamide and an alcohol which boils above the cure temperature of the prepolymer and which preferably is hexyl carbitol. The prepolymer is formed with sufficient chain transfer agent to establish a weight average molecular weight of the prepolymer less than about 25,000. The prepolymer is heat curable to form a solid polymer with excellent compression set, tensile strength, and fuel resistivity. The method of formulating these polymers is also disclosed.

Abstract: A solventless prepolymer which is liquid at room temperature and cures at about 350.degree. F. The novel prepolymer is formed from a rubber monomer; acrylonitrile or methacrylonitrile; and an ether derivative of methylol acrylamide. The ether is formed from methylol acrylamide and an alcohol which boils above the cure temperature of the prepolymer and which preferably is hexyl carbitol. The prepolymer is formed with sufficient chain transfer agent to establish a weight average molecular weight of the prepolymer less than about 25,000. The prepolymer is heat curable to form a solid polymer with excellent compression set, tensile strength, and fuel resistivity. The method of formulating these polymers is also disclosed.

Abstract: A heat curable, solventless liquid prepolymer formed from an N-(R-oxymethyl) acrylamide; a rubber monomer such as isoprene, butadiene or alkyl esters of acrylic acid; and a nitrile monomer such as acrylonitrile or methacrylonitrile. The prepolymer is formed with sufficient chain transfer agent to establish a weight average molecular weight which is less than about 25,000. The prepolymer is heat curable to form a solid polymer with excellent compression set, tensile strength and fuel resistance. The method of formulating these polymers is also disclosed.