Aramid-short-fiber reinforced rubber as a tire tread composite

• Published in: Journal of applied polymer science Vol. 113; no. 2; pp. 1355 - 1363
• Main Author: Kashani, Mehdi Razzaghi
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.07.2009; Wiley
• Subjects: Abrasion; Abrasion resistance; Application fields; Applied sciences; Aramid short fibers; Composites; dynamic-mechanical-thermal properties; Exact sciences and technology; Extrusion; Fibers; Forms of application and semi-finished materials; Polymer industry, paints, wood; rolling resistance; Technology of polymers; tire tread compound; Tires; Traction; Treads; Vulcanizing; Short fiber; Synthetic fiber; Fiber reinforced material; Dispersion reinforced material; traction; Property processing relationship; Composite material; rolling resistance; dynamic-mechanical-thermal properties; Vulcanizate; Wear resistance; Diene polymer; Polymer blends; Carbon black; Swelling; Mechanical properties; Natural rubber; Tensile property; Experimental study; Hybrid composite; Tyre; Vulcanization; Dynamic mechanical properties; Butadiene polymer; Extrusion; Aramid fiber; Fiber orientation; tire tread compound; Aramid short fibers; Application; Tread
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.30026

Mechanical and dynamic-mechanical properties of a typical tire tread compound reinforced with one part aramid short fibers were investigated in order to predict the effects of fibers on tire tread performances such as rolling resistance and traction. Rubber processing, including mixing and extrusion, was performed in an industrial scale. Fiber orientation as a result of extrusion was evaluated quantitatively and qualitatively using mechanical anisotropy in swelling and scanning electron microscopy, respectively. Unidirectional tensile tests revealed higher modulus, but slightly lower strength and elongation at break for the composites stretched in the longitudinal (orientation) and transverse directions than those for the isotropic reference compound with no fiber. Dynamic mechanical thermal analysis showed that relative values of loss factor for the longitudinal and transverse composites and the reference compound depended on the state of polymer as glassy or rubbery. Therefore, a high loss factor at lower temperatures and a low loss factor at higher temperatures predicted a balanced improvement of tire traction and rolling resistance as a result of fiber addition. Heat build-up and abrasion experiments showed that addition of fiber did not deteriorate other performances of tire tread. Also, the fibers had negligible effects on processing and vulcanization characteristics of the composite.