The Goodyear Tire & Rubber company (Goodyear) has banked on soybean oil to replace petroleum-based oils in many of its premium tyre brands over the last couple of years. The environmentally-friendly vegetable byproduct has been able to meet the same performance requirements — such as rolling resistance, wet and dry performance, and treadwear — found in tyres with heavy naphthenic (petroleum) oils.
According to Robert Woloszynek, Chief engineer of polymer science for Goodyear, customers have more requisite demands today: they seek durable wet and snow performance; increased fuel efficiency and tread life; as well as manufacturing efficiency and sustainability. All of this can be achieved with complex formulations and compounds in tyre manufacture.
Goodyear has seen success with petroleum-based oils in the past, through compounding and modifications, however, the environmental impact was significant.
The company has since partnered with the United Soybean Board (USB) to manage the performance of tyres and reduce reliability on petroleum-based oils. Goodyear has found soybean oil to be “domestic, abundant and renewable” and possess key attributes including thermal stability and compatibility with rubber compounds.
“USB promotes Goodyear products and provides new opportunities to market this technology to our customers,” Woloszynek said. “[Soybean oil] is a renewable resource, compound adjustments are possible and various grades are available. This is a growing trend with one of the lowest environmental impacts for raw materials in industrial-use applications.”
In addition, soybean oil possesses better miscibility with SSBR compared to naphthenic oils, as soybean oil is a better plasticiser with the same viscosity. Soybean oil also has a very low glass transition temperature, remaining softer at lower temperatures than naphthenic oils.
“This means better manufacturing capacity and a reduction in the energy needed in overall production. A lower amount of soybean oil (roughly half) is required to provide the same level of extension. And there is no penalty in terms of processing.”
Soybean oil has replaced petroleum oil entirely in Goodyear’s popular Assurance Weather Ready tyre; the Eagle Enforcer All Weather tyre, used on police cruisers; and the Eagle Exhilarate tyre, all introduced over the last three years.
Goodyear’s recent partnership with sports fashion retailer Sketchers also finds soybean oil being compounded into shoes for enhanced wear and stability.
“Soybean oil is delivering for Goodyear – because of these successes and our continued development, we have a long-term goal of fully eliminating petroleum oils by 2040,” Woloszynek said.