Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer

Authors: Jong, Lei

Submitted to: Materials Chemistry and Physics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2017
Publication Date: 1/1/2018
Publication URL: http://handle.nal.usda.gov/10113/5922764
Citation: Jong, L. 2018. Improved natural rubber composites reinforced with a complex filler network of biobased nanoparticles and ionomer. Materials Chemistry and Physics. 203:156-165.

Interpretive Summary: Most rubber applications require rubbers to have higher strength by reinforcing rubbers with fillers. Rubbers from renewable sources such as natural rubber composites have a wide variety of applications such as damping supports, machine belts, seals, hoses, gaskets, etc. Previously, we showed that soy protein nanoparticles increased the strength of natural rubber. In this development, we further enhance the reinforcement ability of soy protein nanoparticles with functionalized rubber nanoparticles. The synergistic effect of nanoparticles significantly improves the strength of natural rubber composites reinforced with soy protein nanoparticles. This development will create new markets for soybean crop and flour, and will be beneficial to soybean and natural rubber growers and processing industries.

Technical Abstract: Biobased rubber composites are renewable and sustainable. Significant improvement in modulus of rubber composite reinforced with hydrophilic filler was achieved with the inclusion of ionomers. Soy particles aided with ionomer, carboxylated styrene-butadiene (CSB), formed a strong complex filler network in rubber. The effect of CSB caused Young’s modulus and the tensile stress at 100-300% elongation to increase significantly while maintaining good tensile strength. The optimum concentration of CSB in natural rubber that produced the greatest improvement in tensile stress at higher elongation ratios and shear elastic modulus was determined. CSB improves the cohesion within the composites. The increase of reinforcement factor with increasing CSB and filler concentration in the composites indicates that the effect of CSB increased the reinforcement of soy nanoparticles more significantly at higher than lower filler concentrations. The mechanical properties of the composites were also compared to carbon black reinforced natural rubber composites. The result indicates great potential for tire tread applications.