Study On Properties And Reinforcing Mechanism Of NBR/OMMT Nanocomposites

NBR/OMMT composites were prepared by melt intercalation method, the effect of OMMT on NBR was studied and the reinforcement mechanism of OMMT was proposed.XRD, TEM and TG were used to investigate the morphology and the thermal stability of the composites. It was shown that OMMT layers were dispersed as nano-level in the NBR matrix and formed a type of intercalated nanocomposites. The NBR/OMMT nanocomposites showed perfect thermal stability.The effect of OMMT contents on mechanical properties was studied. The results showed that OMMT layers with ultra high aspect ratio and fine dispersed structure endowed the nanocomposites with excellent mechanical properties. The tensile strength, tear strength, hardness, modulus at 100%, and 300%, elongation at break of NBR/OMMT nanocomposites increased with the increase of OMMT contents.The oil resistance, solvent resistance, aging property, curing characteristics and processing property were investigated. With the increasing contents of OMMT, both the mass variation (△m%)and volume variation(△V%) decreased, which meant the oil resistance of nanocomposites improved. Good barrier properties of OMMT layers made the swelling performance in toluene become better than carbon black and MMT. The aging property measurement results showed that the retention of Modulus at 100% improved, the retention of tensile strength increased firstly and then decrease, the retention of elongation at break decreased with the increasing contents of OMMT. The data of the analyzing the of NBR/OMMT nanocomposites, showed that the scorch time(t10) shorted obviously and the optimum cure time(t90) prolonged gradually with the increasing OMMT contents. The changing value of Mooney viscosity showed that NBR/OMMT nanocomposites has better processing property than NBR/carbon black (N660).Crosslink density was measured by equilibrium swelling method. The crosslink density value of NBR/OMMT nanocomposites increased firstly and then decreased, while the value of NBR/Na-MMT compsites decreased gradually. When the OMMT amount was 5phr, the crosslink density presented a rising tendency with the increasing accelerator amount.The reinforcement mechanism of OMMT was studied in the thesis. The relationship between crosslink density and tensile property were studied. By the chemical extraction method, we determined the bound rubber contents. The reinforcement mechanism was made a model. Because of the special effect of OMMT layers and the orientation and slippage during the tensile course, the mechanical performance of nanocomposites was enhanced.