Lanthanum chloride and sodium p-aminosalicylate were used as raw materials to syn-thesize a new environmental-friendly accelerator lanthanump-aminosalicylate(PAS-La)by precipitation method.The product was characterized and its mole-cular formula was determined to be La(C7H6NO3)3·H2O by elemental,thermal and infrared spectral analysis.The effects of PAS-La on the vulcanization charac-teristics,crosslinking density and mechanical pro-perties of natural rubber were investigated using ro-torless vulcanzation apparatus,equilibrium swelling method and universal testing machine,and the vul-canization kinetics were analyzed.The results showed that with the increase of PAS-La amount,there was a maximum value of positive vulcanization time of natural rubber,and the scorch time firstly decreased and then increased.The crosslinking den-sity of vulcanized rubber increased,and the mecha-nical properties were significantly enhanced.When PAS-La was added at amount of 1.2 phr(by mass),its vulcanization promotion effect on natural rubber was optimal.Kinetic calculations revealed that the reac-tivity of the crosslinked precursors was enhanced with the increase of PAS-La amount,and the activa-tion energy decreased first and then increased.
关键词
对氨基水杨酸镧/天然橡胶/硫化促进剂/稀土/活化能
Key words
lanthanum p-aminosalicylate/natu-ral rubber/vulcanization accelerator/rare earth/ac-tivation energy
维普
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