Effect of Carbon Black Dispersion on Hardness Properties of Polyurethane Elastomer for Wheel Dolly

This study investigates the enhancement of hardness and mechanical properties of PPG-based polyurethane elastomers for wheel dolly applications through the incorporationof carbon black and the use of Plast 002 as a dispersing agent. The challenge addressed is the inherent lower mechanical performance of cost-effective PPG-based polyurethane compared to traditional polyester-based alternatives. Three dispersion methods were explored: the impactof Plast 002 on carbon black distribution, varying carbon black content (1, 3 and 5 phr), and comparing high-speed agitation with ultrasonic dispersion. The results indicate that without Plast 002, carbon black tends to agglomerate, leading to significant differences in hardness between the top and bottom of samples, particularly at higher carbon black contents. The addition of Plast 002 significantly improved dispersion, resulting in uniform hardness. Ultrasonic dispersion had more effective than high-speed agitation, delivering higher and consistent hardness values across the sample. Optimal mechanical performance was observed at 1 and 2 phr of carbon black, where tensile strength and modulus improved. The optimized carbon black content and ultrasonic dispersion can significantly enhance the performance of PPG-based polyurethane, offering a more economical alternative to polyester-based polyurethanes for wheel dolly applications.