This study investigates how the softening point (SP) of hydrocarbon resins influences the in-rubber properties of carbon black-filled styrene-butadiene rubber compounds. Five resins with identical chemistry but SPs ranging from 10°C to 160°C were evaluated as full replacements for TDAE oil. Results show that low-SP resins act as plasticizers, enhancing processability but reducing mechanical strength, while high-SP resins behave like reinforcing fillers, increasing viscosity, hardness and tensile strength. SP also affects curing behavior, filler dispersion and dynamic properties. Temperature-dependent tests reveal performance shifts when resin SP is exceeded, offering a pathway to tailor tire tread compounds for specific attributes.

• The overall performance of carbon black-filled SBR compounds using hydrocarbon resins as an alternative to TDAE
• The role of the softening point of resins on in-rubber properties
• How the softening point of resins ingluences the dispersion of the filler in the rubber compound
• Effect of temperature on resin performance in rubber compounds