Study On The Technology Of Ground Rubber Powder Devulcanized By Microorganism

Devulcanization of waste rubber poses a challenging environmental, economical and disposal problem in the world. In this paper, ground rubber powder (GRP) was devulcanized by GSH. GSH containing active hydrosulfide group which can react with the-S-S-crosslink, and have the-S-S-crosslink break down, and then rubber was devuicanized. In this dissertation, the influence of temperature, reaction time, solvent dose, phase transfer catalyzer dose and GSH dose on devulcanized of ground rubber powder were studied. The results indicated the swelling ratio of devulcanized rubber powder (DRP) was higher than the ground rubber powder(GRP), and the crosslink density of DRP was lower than GRP. The experimental results showed that the effect of temperature was not obvious, so the rubber powder can be devulcanized at room temperature. The optimally reaction time of NR rubber powder was2h and that of SBR rubber powder was6-8h. For the both rubber powder, the optimum dose of solvent was78phr.The phase transfer catalyzer have a promoter action to the devulcanization and it’s optimum dose was4-6phr.The swelling ratio of rubber powder was lower when increase the dose of GSH.Secondly,NR rubber powder was devulcanized by yeast which fostered in lab. Likewise, the impact of temperature, reaction time, solvent dose, phase transfer catalyst dose and GSH dose on devulcanized of ground rubber powder were researched. The result of the experimentation indicated that yeast have some effect to devulcanization.In this paper, the category and dose of the phase transfer catalysts were also studied. Phase transfer catalysts used in this work were cation surface active agent CTMAB, DDBAC and non-ionic surface active agent TW80. The experimental result indicated that devulcanized rubber which uses DDBAC or TW80as phase transfer catalyst had a better mechanical properties and lower swelling ratio than the devulcanized rubber which use CTMAB as phase treansfer catalyst.In this work, waste rubber powder devulcanized by Thiobacillus was studied. The XPS result indicated that the sulfur content in the surface of rubber powder was reduced after treated by Thiobacillus15days.At last, The GRP and DRP (devulcanized by GSH) were incorporated into nature rubber matrix with different loading. Cure characteristics, dynamic mechanical property, tensile fractured surface, and mechanical properties of RP/NR compound have been studied. The results indicated the composite loading with DRP had better properties than the one loading with GRP. Expressed the microorganism can reduce the crosslink density of the ground rubber powder.