Phenolic resin modified by boron-silicon with high char yield

In order to improve the thermal stability, oxidation resistance and storage stability of phenolic resin, and to avoid complicated synthetic methods, herein, a facile, environmental friendly, controllable and low-cost strategy was designed and a novel boron-and silicone-containing phenolic resin (BSiPF) was prepared, in which silicone was reacted with commercial boron-modified phenolic resin (BPF). The as-prepared BSiPF solution has a long shelf life (more than 8 months) at room temperature. Structure, molecular weight, gel properties, curing behavior and heat resistance of BSiPF were characterized. Compared with common PF resin, the maximum decomposition rate (Dmax) of BSiPF in N2 and air atmosphere decreased by 0.81%/min and 1.52%/min, respectively, while the char yield at 800 °C(R800) of BSiPF in N2 and air atmosphere increased by 12.0% and 22.5%, indicating that the introduction of silicon and boron obviously enhance the heat resistance and anti-oxidation property of phenolic resin. With superior thermal stability and low viscosity, BSiPF can be used as a novel high performance matrix resin for ablative materials.