Reinforcing Effect of Organo-Modified Fillers in Rubber Composites as Evidenced from DMA Studies

The use of organically enhanced kaolin clay as reinforcing filler for NR(natural rubber)and blends of NR with NBR(nitrile-butadiene rubber)and poly BR(butadiene rubber)system were investigated on the basis of DMA(dynamic mechanical analysis).Kaolin clay was modified using a chemical complex of HH(hydrazine hydrate)and SRSO(sodium salt of rubber seed oil).Intercalation of SRSO into kaolin under optimized condition showed an inter-lamellar layer expansion to 4.668 nm,compared to the characteristic d001 XRD(X-ray diffraction)peak of pristine kaolin at 0.714 nm.The morphology,visco-elastic behavior,modulus property,polymer miscibility and Tg(glass transition temperature)of nano-kaolin filled NR and its blend with synthetic rubbers have been studied in detail.DMA showed a diminution in tanδpeak height and a modulus shift in correspondence with increased CLD(crosslink density).Pure NR shows only~1%increase in storage modulus(E′)while adding nanoclay rather than micron sized pristine clay under experimental conditions,because of the feeble interaction between filler and matrix,as compared to blend.An increment of~76%and~117%in E′was recognized by the addition of 4 wt%nanoclay in blends such as BR mK and NBR mK.With loss modulus(E″)pure NR shows only~7%decrease while adding nanoclay,compared to blend.A decrement of~54%and~55%in E″by the addition of 4 wt%nanoclay in BR mK and NBR mK blends were observed.As a whole,DMA was performed to figure out the effect of surface modification enabling to materialize composite.