Structure of 1,2-polybutadiene drying oil mixture crosslinked by autoxidation

The structure of 1,2-syndiotactic polybutadiene/drying oil mixture crosslinked by autoxidation is discussed from the viewpoint of surface reactions in crystalline polymers. Drying oils, soy bean oil, and boiled bean oil, were partially miscible to 1,2-polybutadiene and the solid mixtures consist of a crystalline region of pure 1,2-polybutadiene and an amorphous region of the mixtures. The crosslinking reaction of the mixture film proceeds by the decomposition of peroxide that is formed in the oil, with oxygen diffusing from the film surface. After this reaction, the rubbery surface is hardened to acquire toughness and to suppress the diffusion of oxygen. The crosslinking reaction mainly occurs in the rubbery, amorphous region where oxygen has a large diffusion rate. The resultant film is a crosslinked soft material with hard, anti-staining, and anti-abrading surface that is promising as a flooring material.