Study On The NR/LLDPE TPV Composite Filled With Coconut Shell Powder

The masterbatch of nature rubber(NR) has been prepared on Open mixing mill before blended with linear low density polyethylene(LLDPE)on the two-roll mill by dynamic vulcanization.The test pieces of NR/LLDPE TPV composites filled with coconut shell powder were compression molded on Plate vulcanizing machine.There are many highly hydrophilic hydroxyl(alcoholic hydroxy group)in the structure of coconut shell powder particles, which due to poor compatibility between coconut shell powder, NR and LLDPE.Coconut shell powder has poor dispersibility with the polymer matrix and weak interfacial bonding strength between coconut shell powder> NR and LLDPE, which due to poor comprehensive properties of NR/LLDPE TPV composites filled with coconut shell powder. For the reason that the research was based on the effecting on mechanical properties of NR/LLDPE TPV blending-ratio of NR/LLDPE, the adding means of coconut shell powder and coconut shell powder on particle size.Static mechanical properties’tests studied the effect of compatibilizing to composites by the way of studing the surface modification effect of NaOH solution by the alkali treatment on coconut shell powder particles and adding LLDPE-g-(GMA-co-St)as the compatibilizer into TPV during blending.The composites were analyzed by SEM、DMA、TG and swelling index, and tested the microscopic morphological structure、 dynamic mechanical properties, thermal decomposition performance and solvent resistance;and studied the thermoplastic of composites compatibilized by LLDPE-g-(GMA-co-St).The result shows that suitable rubber and plastic ratio was60/40; appropriate filling means of coconut shell powder and smaller particle size result in better comprehensive mechanical properties of composite;a suitable alkali solution can keep a well properties level of TPV composites filled with coconut shell powder;and the comprehensive mechanical properties of composite can be further improved by adding LLDPE-g-(GMA-co-St) during the blending.The SEM analysis indicated that the untreated coconut shell powder showing the poor dispersibility in the LLDPE matrix,as well as,the weaker interaction between the surface of the LLDPE matrix and the untreated coconut shell. However,the dispersibility of the coconut shell powder was enhanced with the incorporation of LLDPE-g-(GMA-co-St) as the compatibilizer. Besides, the surface between the coconut shell powder and the coconut shell powder and the LLDPE matrix could sustain, transfer and homogenize the stress due to the strong interface bonding strength. Finally,the mechanical property of the NR/LLDPE TPV composites won’t lost obviously with the addition of the coconut shell powder.The study of the DMA indicated that the ability to resist deformation and low temperature resistance of the composites with the untreated coconut shell powder deteriorated. However,the value of E keep higher at the wide temperature range and show the minimum peak value of tanδ,as well as the lower Tg value for the compatibilized composites,the composites show the better deformation resistance,low temperature resistance and low-temperature toughness at the high or low temperature.The TG analysis indicate that the thermal decomposition of the composites,which filled with untreated coconut shell powder,decreased due to the thermostability of the neat coconut shell powder seems to be relatively poor at the high temperature. The compatibilizer,LLDPE-g-(GMA-co-St) enable the mass retention percentage of the composites keep high. The maximum weight loss rate of the composites increased3.3-.6.1and4.1℃for the weightlessness temperature at the weight loss of5%,the first and second section respectively.The other studies demonstrated that the compatibilized composites showing the better solvent resistance property and repeat processability(thermoplasticity).The aim of the study is to provides a valuable reference,which prepared the NR/LLDPE TPV composite,filled with the abandoned coconut shell powder,with the excellent comprehensive performance and practical value-in-use.