PITTSBURGH—With the current trend toward replacing petrochemical additives with natural substances, the best natural additive for rubber and thermoplastics compounds has been around at least since the time of Henry Ford, according to the United Soybean Board.
“Ford Motor Co. took the initiative to develop rubber compounds with soybean oil additives, and he did some interesting work,” said Robert Brentin, commercialization manager-rubber for the Midland, Mich.-based USB. “And Ford has the strongest sustainability initiatives of any car maker.”
Brentin represented the USB at the International Elastomer Conference in Pittsburgh Oct. 11-13. The USB booth displayed tires, belting and other rubber products made with soybean oil, as well as literature and product guides about soybean oil.
Ford is not the only company that is enthusiastic about soybean oil, according to Brentin. Goodyear has an ongoing project with the USB to replace petroleum-based oils in tire tread compounds with soybean oil. Goodyear provides tires to NASCAR that contain soybean oil, Brentin said.
Also, Bridgestone has developed an agricultural concept tire containing soybean oil for large, four-wheel-drive tractors, according to the USB. “Soybean oil constitutes more than 10 percent of the 900-pound Firestone farm tire,” said a USB market opportunity summary for soybean oil use in rubber.
Soybean oil is already an established ingredient in some rubber and plastics formulations, according to the USB. Epoxidized soy oil is used as a plasticizer/stabilizer in plastics and rubber, and vulcanized soybean oil-—as well as other vulcanized vegetable oils—improves ozone resistance and flow properties when used as an extender and rubber substitute.
Applications for soybean oil extend across virtually the entire rubber product line, including tire retreading, molded and extruded goods, belts, hoses, wire and cable, seals, footwear, roofing, coated fabrics and rubber-covered rolls, the USB said.
The USB booth displayed abstracts on research into soybean oil. These included research projects on soybean-based elastomers, soy-based acrylic thermoplastics, soy-based surfactants and oligomers for asphalt rejuvenation and modified soybean oil as a processing oil for rubber.