Vulcanizing rate of polyepichlorohydrin (CHR) with 2-R-4, 6-dimercapto-s-triazine (I) is influenced by the structure of R, and the rate increases in order of R: SH<OCH
3<N(C
4H
9)
2. In addition, the rate is remarkably increased by the copresence of amines with pKa over 9 such as 1, 3-diphenylguanidine. The organic or inorganic salts of the amine as well as the amine generator such as N-cyclohexyl-2-benzothiazole sulfenamide or Cu-dibutyldithiocarbamate show the similar accelerating activity. The mechanical properties of the vulcanizates with I are improved with the increasing of hydrohobicity of R,
i. e, in order of SH<N(C
2H
5)
2<N(C
4H
9)
2<N(C
6H
5)
2, N(C
6H
11)
2<N(C
8H
17)
2. The thermal ageing stability is not improved in the presence of commone antioxidant such as phenyl-β-naphthyl-amine and
t-butylphenol novolak. The latent vulcanizing agents, however, show the remarkable stabilizing activity. The best examples are 2-mercaptobenzi-midazole and Ni-dibutyldithiocarbamate, which are used as antioxidant. The vulcanizing compositions of trithiocyanuric acid-MgO-1, 3-diphenylguanidine, and 2-dibutylamino-4, 6-dimercapto-
s-triazine-MgO give the most excellent vulcanizates in thermal ageing stability and mechanical property in comparing with the well known composition, e.g. 2-mercaptoimidazoline-Pb
3O
4, and hexamethylenediamine carbamate-Pb
3O
4.
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