| The regeneration of vulcanized NR powder by diallyl disulfide(DADS) was investigated,and the influence of DADS addition level and regenerative process on regenerative effect was studied.Fourier transform infrared spectroscopy analysis and scanning electron microscope were used to preliminarily inquire into the regenerative mechanism of vulcanized NR powder by DADS.The results showed that,better regenerative result could be achieved with 6～10 phr DADS at the 60 ℃ for 1 day and 5-minute shearing.DADS could break crosslink of NR vulcanizate,and might also rupture the main chains of molecules,resulting in lower crosslink density of NR vulcanizate.Furthermore,DADS could even partially dissolve NR vulcanizate.With the assistance of shear force,S—S bonds of DADS and multi sulfur bonds of NR vulcanizate could be cracked into free radicals containing sulfur,and the crosslink density decrease of NR vulcanizate could be achieved through combination of the two kinds of radicals. |
