Tire Tread Performance Modification Utilizing Polymeric Additives

Tire manufacturers have long grappled with the challenge of balancing the conflicting tire attributes of traction, rolling resistance, and treadwear. Improvements to one of these “magic triangle” attributes often comes at the expense of the other attributes. Recent regulations have further increased the pressure on manufacturers to produce optimized tires with minimal performance compromises. In order to meet this challenge, the tire industry is looking to new material systems beyond the traditional tire tread components. Polymeric materials beyond the base elastomers and processing oils used in tread provide opportunities to modify the physical and viscoelastic properties of tread. In this study, various polymeric materials were evaluated as additives in a model tire tread formulation. Hydrocarbon resin, high styrene resin, and thermoplastic styrene elastomers were added to the model formulation at various loading levels and through various addition strategies. The thermal behavior of the raw polymeric additives was characterized utilizing differential scanning calorimetry (DSC). The impact of the polymeric additives on the tread compound was assessed by evaluating the cure kinetics, physical properties, and viscoelastic properties of the experimental compounds. The viscoelastic properties, as measured by dynamic mechanical analysis (DMA), were utilized to predict the relative tire tread performance attributes. Each polymeric additive evaluated in this study was predicted to modify the tire tread performance in a unique way. The potential advantages and challenges of utilizing the polymeric additives to optimize tire tread performance will be discussed.