Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2014
Publication Date: 2/1/2015
Publication URL: http://handle.nal.usda.gov/10113/62269
Citation: Jong, L. 2015. Influence of protein hydrolysis on the mechanical properties of natural rubber composites reinforced with soy protein particles. Industrial Crops and Products. 65(1):102-109.
Interpretive Summary: The dissociation conditions of soy protein in water change the size and surface composition of the protein particles, which in turn change the mechanical properties of natural rubber enhanced with these particles. Natural rubber composites have a wide variety of applications such as machine belts, seals, hoses, gaskets, etc. In this development, the protein dissociation conditions were investigated to optimize the mechanical properties of the natural rubber composites by optimizing the dissociation conditions. We found that less dissociated soy protein yielded better mechanical properties than highly dissociated soy protein. This development will create new markets for soybean products, and will be beneficial to soybean grower and processing industries.
Technical Abstract: For natural rubber applications, the reinforcing fillers are used to improve the mechanical properties of the rubber. Soy protein particles have been shown to reinforce natural rubber. The hydrolysis conditions of soy protein are studied to understand its effect on the particle size and size distribution, and their subsequent effect on the mechanical properties of natural rubber. The reinforced and crosslinked rubber composites showed an improvement on modulus, tensile strength, and toughness compared to natural rubber. The composites reinforced with less hydrolyzed soy protein and the composites prepared under alkali condition had greater tensile strength, modulus and toughness, while the composites reinforced with highly hydrolyzed soy protein and the composites prepared under acidic condition had greater elongation. The highly hydrolyzed soy protein was found to decrease the total crosslinking density and decrease the modulus at larger strain region. The structure-properties of the composites were characterized with stress-strain, dynamic frequency sweep, transmission electron microscopy, and swelling experiments.