Curing behaviour and properties of a novel benzoxazine resin via catalysis of 2-phenyl-1,3,2-benzodioxaborole

In this work, 2-phenyl-1,3,2-benzenediolborane (PBO) with a five-membered cyclic phenylboronate structure was introduced into a benzoxazine resin to improve its processability and thermal resistance. PBO catalysis was beneficial at accelerating the curing reaction of PBO modified BZ (PBOZ), leading to a lower exothermal peak temperature (186 °C) and a shorter gelation time than for BZ (238 °C). PBO was successfully incorporated into the network structure of the BZ and phenylboronate structures formed during curing. The TGA and DMA results showed that the cured PBOZs exhibited excellent thermal stability and a higher crosslinking density than cured PR. The char yield and glass transition temperature of the cured PBOZ increased by 12% and 38 °C, respectively, relative to the BZ. The interlaminar shear strength of the high silica glass cloth-reinforced PBOZ composites were higher than that of the BZ composite due to the good interfacial adhesion properties between the PBOZ and glass fiber observed in the SEM results. This work provides a new strategy to develop BZs with excellent comprehensive properties.