Reinforcement of latex rubber by the incorporation of amphiphilic particles

Authors: Kim, Sanghoon; Adkins, Jason; Biswas, Atanu

Submitted to: Journal of Rubber Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2016
Publication Date: 7/18/2017
Publication URL: https://handle.nal.usda.gov/10113/5852176
Citation: Kim, S., Adkins, J.E., Biswas, A. 2017. Reinforcement of latex rubber by the incorporation of amphiphilic particles. Journal of Rubber Research. 20(2):87-100.

Interpretive Summary: Most current rubber products are manufactured from synthetic latex, which is a dispersion of fine polymer particles suspended in aqueous medium. The fabrication of latex rubber begins with forming sheets of rubber from latex suspension. In this report, it is shown that the mechanical properties of latex rubber are greatly improved by mixing latex with nanoparticles during the fabrication process. The employed nanoparticles are made from an animal protein and a biodegradable synthetic polymer, and their sizes are on the order of one hundred nanometers (one nanometer is one thousandth of a millimeter). With the inclusion of only 3% of protein-based nanoparticles, the mechanical properties of fabricated rubbers are improved up to 250%. This research shows that the incorporation of nanoparticles will reduce the repulsive forces between latex particles and increases the mechanical strength of the final product. This research would impact the rubber processing industries that develop rubber products with improved mechanical properties. Rubber products such as belts and bands can be produced with improved properties. This research would also help scientists in academia and industry develop improved rubber products by incorporating bio-based materials.

Technical Abstract: Latex rubbers are fabricated from latex suspensions. During the fabrication process, latex particles are bound together while water is removed from the suspension. This report shows that the mechanical properties of latex rubbers can be improved by incorporating a small amount of amphiphilic submicron particles as interface modifier. The incorporated particles were prepared from bovine serum albumin (BSA) and ethyl cyanoacrylate (ECA). These particles changed conformation while mixing with latex suspension, and bound to latex particles to induce aggregation of latex. The improved mechanical properties of the produced reinforced latex rubbers were characterised by mechanical analysis (stress-strain). Incorporation of microparticles into latex improved mechanical properties such as % elongation and energy at break up to ~250%. On the other hand, tensile strength and tensile modulus were not significantly affected by the incorporation of particles.Experimental results showed that the optimum BSA:ECA weight ratio for particles is 1:3, and the optimum percentage of particles is 3%. The mechanism for the reinforcement of latex rubber by microparticles has been elucidated by zeta potential analysis and optical microscopy.