Abstract:

The selective hydrogenation of carbon-carbon double bonds in acrylonitrile-butadiene rubber (NBR) so-lution was investigated,with the intermetallic hydrides forming from hydrogen-storage alloys LaNi₅,LaNi_4.8Cu_0.2 and MlNi₅ (CoMnAl)_x as catalysts and hydrogen sources.NBR and the hydrogenated acrylonitrile-butadiene rubber (HNBR)were then analyzed by means of IR, ¹HNMR and iodometric analysis.In addition,the surface morpholo-gY and composition of the alloys were analyzed with SEM ,etc.The results demonstrate that,without any surface treatment, LaNi₅ and LaNi₅ Cu_0.2 can catalyze the hydrogenation of NBR,while the hydrogenation degree of HNBR catalyzed by MlNi_5-x(CoMnAl)_x is naught,that surface treatment hardly influences the catalytic activity of LaNi₅,but seriously influences that of MlNi_5-x(CoMnAl)_x ,that the hydrogenation degree of NBR achieves 14.7% after proper surface treatment to MlNi_5-x(CoMnAl)_x  (such as immersing in KOH and KBH₄ solutions and so on),and that the addition of metals such as Pd and Pt can enhance the activity of the alloys for hydrogenation,with the hv-drogenation degrees of HNBR respectively achieving 22.0% and 18.7%.

Key words: hydrogen-storage alloy, acrylonitrile-butadiene rubber, hydrogenation, activity