Preparation and Properties of Boron Modified Phenolic Resin for Automotive Friction Materials.

To address the thermal fade problem of brake pads, a boron-modified phenolic resin with better temperature resistance is intended to be developed. By introducing B-O bonds and high-temperature-resistant units, the thermal decomposition temperature of the phenolic resin will be increased. The modified resin is obtained through a step-growth polymerization reaction and then incorporated into the brake pad formulation to be hot-pressed into samples. The thermal decomposition temperature of the resin is measured by TGA, and the thermal fade performance of the brake pad samples is analyzed through friction and wear experiments. The results show that the introduction of B-O bonds and the doping of nano-alumina have increased the thermal decomposition temperature of the phenolic resin to 480 °C, meeting the expectation. Brake pads molded with this resin as an adhesive showed significantly better thermal degradation than those made with ordinary phenolic resin. Meanwhile, during the braking process, the brake pads made from this resin form a complete and continuous friction film, demonstrating good mechanical properties and thermal fade performance. The wear amount under the entire braking test is also acceptable. In addition, an exploration of the thermal fade mechanism is carried out.