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IMPROVING WINTER TIRE TRACTION AND ROLL RESISTANCE WITH UNIQUE LOW TEMPERATURE ESTERS
by
Stephen O’Rourke
The HallStar Company
5851 West 73rdStreet
Chicago, IL 60638
(Ph) 708-594-5070; (Fax) 708-594-1185
E-mail: sorourke@hallstar.com
Abstract
Traditional tire compounds are compounded with treated distillate aromatic extracts and aromatic process oils. These oils have excellent compatibility and perform quite well for most tire tread conditions. These oils improve processing and mixing of the rubber compounds.
Physical properties that are influenced by these oils are hardness and elongation. One of the most important properties is the effect on glass transition, Tg, which can effect winter traction, roll resistance and wet traction. In this study specialty esters were evaluated to improve winter traction and wet traction in a SBR model tread compound.
Esters are well known for plasticizing traditional polymers used in industrial rubber goods, but are not normally used in non-polar elastomers that are used in tire tread compounds.
Esters have the ability to lower the Tg of polymers more efficiently than petroleum oils and can be used in combination with these oils in tire compounds without compatibility issues. Specialty esters replaced one-half of the normal oil content in the compounds evaluated. Physical properties were compared along with dynamic mechanical analysis.
The results show that the specialty low temperature esters improve winter traction significantly and improve or maintain roll resistance. Also in this study another specialty ester was investigated that increased wet traction dramatically versus petroleum oils.