Methacrylamide grafted elastomer composites reinforced with biobased particles

Authors: Jong, Lei

Submitted to: Journal Polymer Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2018
Publication Date: 3/1/2018
Citation: Jong, L. 2018. Methacrylamide grafted elastomer composites reinforced with biobased particles. Journal Polymer Research. 25:64. https://doi.org/10.1007/s10965-018-1468-8.

Interpretive Summary: Expanding new uses of soybean can increase the economic prosperity of soybean farmers and processors. Soybean derived particles in combination with natural rubber were found to have good mechanical strength for general rubber products, but still require strength improvement to become commercially competitive. We have increased the strength of such rubber material through chemical modifications for practical uses. This result has increased the potential of using more soybeans in new applications and therefore will increase the value of soybean and natural rubber, which will economically benefit soybean and natural rubber businesses.

Technical Abstract: Modulus of rubber can be improved with grafting of unsaturated monomers. To increase the modulus of bio-based rubber composites, methacrylamide was grafted onto natural rubber composites reinforced with bio-based hydrophilic particles. Rubber particles in water were modified with methacrylamide using redox free radical initiator. Modified rubber composites have higher crosslinking density, bound rubber, and modulus than the unmodified rubber composites. Without methacrylamide, initiator modified rubber composites have poor tensile strength and elongation. The modified rubber has a greater stress relaxation rate than the unmodified rubber because of interactions between methacrylamide grafts. Relaxation behaviors of modified and unmodified rubber composites are similar because the effect of filler dominates the dissociation process. The rapid increase of reinforcement factors with filler content can be described by the modified Mooney equation. At small strain, the reinforcement factors for both modified and unmodified rubber composites indicate the association of poly(methacrylamide) grafts is the main contribution to the increase of modulus in the modified rubber composites.