Study On The Environmental Regeneration Of Waste Natural Latex And The Properties Of Reclaimed Rubber

With the continues growth in demand for natural rubber (NR) and its products, the domestic demand exceeds supply. It is important to find an effective way to deal with this situation.A torque rheometer was used as a reclaimed device in this paper. Diallyl disulfide (DADS) and activator 420 were selected as environment-friendly additives. The effects of reclaimed temperature, reclaimed time and dosage of regeneration on the properties of reclaimed rubber (RR) were studied. The sol fraction, crosslink density, Mooney viscosity, curing characteristics, mechanical properties of reclaimed rubber were measured. Then homemade reclaimed rubber was blended with Hainan skim rubber (NR-S). The performance of RR/NR-S with different compositions were characterized in order to choose the best compositions.The effcet of DADS on the properties of RR showed that sol fraction and elongation at break of RR increased with increasing reclaimed temperature, crosslink density and Mooney viscosity decreased and tensile strength of vulcanized rubber got maximum at 145?. The increase of reclaimed time caused the decrease of hardness, tensile strength first increased and then slightly decreased. When the amount of DADS varied from 0 to 2phr, the elongation and tensile strength of vulcanized rubber both increased at first and then decreased significantly. Attenuated total reflection infrared spectroscopy (FTIR-ATR) showed that the main structure of rubber did not change after reclamation. Photoelectron spectroscopy (XPS) results suggested that the content of S decrease 58.4% after reclaimation. Taken together, the optimum reclaimed condition of DADS were 145?, 12.5min and lphr.When the reclaiming agent was activator 420, the conclusion was that the sol fraction increased with increasing reclaimed temperature, crosslinking density, minimum torque Ml and hardness had an opposite tendency. With the increasing of reclaimed time, the scorch time t10 increased and the cure time t9o reduced. The tensile strength and elongation at break of vulcanized rubber were 20.6MPa and 682% at 12mim. The optimum reclaimed conditions of activator 420 were 140?,12min and 0.5phr.The results of RR/NR-S with different compositions indicated that with the content of reclaimed rubber increased, the crosslinking density of the composites varied from 1.13×10-4 mol·cm-3 to 1.56×10-4 mol·cm3, value of maximum and minimum torque increased, as well as the dynamic mechanical loss. Tan? peak shifted to the high temperature and tan? peak width broadened in the rubbery region. When the content of reclaimed rubber less than 60phr, the tensile strength of the composite did not change significantly. Greater than 60phr, the tensile strength of the composite dropped 5.6MPa. When the ratio of RR and NR-S at 60:90, the storage modulus G' of composites increased to maximum, the composites had excellent mechanical properties.