Controllable synthesis of boron nitride submicron tubes and their excellent mechanical property and thermal conductivity applied in the epoxy resin polymer composites

A simple method was developed for the controllable synthesis of a novel boron nitride submicron tube using magnesium borate whisker as rigid template. XRD, SEM and other characterizations were carried out to study the phase, microstructure, chemical composition of the samples. The results show that the average inner diameter and the tube length of the boron nitride submicron tube are 0.6 μm and 5–30 μm, respectively. And the surface is loaded with abundant boron nitride nanosheets. The temperature and ammonia flow rate had a significant impact on the structure evolution of the submicron tube. The growth mechanism of the boron nitride submicron tube was also definited based on the experiment results. In addition, submicron tube/epoxy resin composites were prepared. The tensile strength of the composite is 281.4% higher than that of the pure epoxy resin at a low load of 1 wt%. When the load is 2 wt%, the thermal conductivity increases by 312%.