A novel waterborne polyurethane coating modified by highly dispersed nano‐boron carbide particles

Abstract In this study, waterborne polyurethane (WPU) coatings were modified by adding various compositions of nano‐boron carbide (nano‐B4C) particles. In order to achieve proper dispersion of nano‐B4C in WPU and increasing chemical interactions between them, the nano‐B4C particles were treated with polyethylene glycol (PEG) or polypropylene glycol (PPG). The modified surface and microstructure of nano‐B4C were characterized by Fourier transform infrared, scanning electron microscopy and transmission electron microscopy. The deposition experiment was designed to evaluate the dispersion effect of nano‐B4C in PEG or PPG aqueous solution. The physical performance of nano‐B4C modified WPU coatings was measured following the national standards of paints and vanishes. The results revealed that the PEG6000 not only enhanced the interaction between nano‐B4C and WPU but also exhibited a remarkable ability to improve the physical performance of WPU coating. The coating with 15 wt% of nano‐B4C addition exhibited the best performance in terms of abrasion and hardness, which could be attributed to the best uniform dispersion of nano‐B4C particles in PEG6000 aqueous solution.