Role of Amines in Adhesion of Polybutadiene to Glass Substrates I. Reactions of Amines During Peroxide Curing of Polybutadiene

Abstract An attempt to elucidate the role of amines in general, and of 3-aminopropyltriethoxysilane in particular, has been made through a study of the title subject by several different approaches. This paper describes the interactions of amines during curing of the rubber phase. When aromatic or cyclic amines were added, maximum stress at break and minimum swelling ratios were observed when the number of alkoxide radicals generated was equal to the number of hydrogen atoms on the nitrogen of the amines. The order of reactivity was thus no amine > aniline > piperazine > m-phenylenediamine. The greatest effect of aliphatic amines also occurred when the concentration of primary amino groups was equal to the concentration of peroxide; but the behavior was complex and dependent on the backing against which samples were molded. The higher rigidity and reinforcement of the polybutadiene in the presence of low concentrations of amines was attributed to formation of chemical bonds between the amines and the polybutadiene.