Elastomer-Resin Blends. Acrylonitrile Type Synthetic Rubber and Polyvinyl Chloride Resins

Abstract

1. 1,3-Butadiene-acrylonitrile copolymers were mill-mixed with benzothiazoyl disulfide, sulfur, litharge, and vinyl resins, such as Vinylite (VYNW), and Saran and cured to compounds with good tensile strength, modulus, hardness, solvent resistance, and blocking temperature. 2. Results show that higher acrylonitrile type of copolymers give cured Vinylite-rubber blends with higher tensile strength, higher 100 per cent modulus, and greater ultimate elongation to break than low acrylonitrile copolymers. 3. The low temperature properties of the cured blends improve as the acrylonitrile content of the synthetic rubber is reduced. 4. An effective cure at 287° F is obtained in 15 to 30 minutes by using 2 parts of accelerator and 2 parts of sulfur per hundred parts of 1,3-butadieneacrylonitrile type copolymer-Vinylite blends. Added amounts of sulfur, and accelerator did not improve the properties or decrease the cure time at 287° F. 5. Some of the cured blends studied are free of tackiness at temperatures as high as 230° F. 6. Some stabilizers for vinyls tested as well as sodium acetate can be used to activate sulfur cures in 1,3-butadiene-acrylonitrile copolymer-Vinylite blends to formulate light-colored transparent products.