Investigation of the Applicability of Thermoset Polyurethane Resin in Automotive Bushing Systems

Rigid polyurethane materials (PUR) form an important subgroup of polymeric materials. These materials are produced by gradual polyurethane reactions of isocyanates and compounds called polyols containing hydroxyl groups. These basic reactions lead to many products with various properties of polyurethanes that can be used for different purposes. The diversity of the obtained forms of PUR is possible by changing the raw materials and their mixing ratios. In this study, it was investigated whether the polyurethane bushings we produce can be used instead of the rubber bushings that are widely used today. In order to make the mechanical properties of polyurethane bushings similar to rubber bushings, the amount of hardening resin was changed and glass ball, SLES, and carbon powder materials were added. Test results showed that carbon fiber powder improved the strength and ductility of polyurethane, enhancing bushing performance. Glass beads increased ductility but reduced tensile and compressive strength. The addition of SLES caused polyurethane to foam, preventing the achievement of desired strength values. Polyurethane’s tensile strength increased with strain rate, but the elongation decreased. Under tensile loading, polyurethane was more sensitive to strain rate. In fatigue testing, stiffness decreased over time in the tensile region but remained constant in compression. Bushing production using the casting method passed durability tests, indicating that polyurethane resin could serve as an alternative to the traditional rubber in automotive applications.