Preparation and Properties of Chinese Lacquer Modified by Methylolureas

In this study, different molar of methylolureas (MMU) were used to improve the properties and drying speed of the raw lacquer (RL). The drying time, gloss, pencil hardness and impact resistance of the lacquer film were tested. The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis (TGA), fourier infrared spectrometer (FT-IR) and nuclear magnetic resonance (NMR) analysis, respectively. The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer. The TGA analysis showed that the modified lacquer had high thermal stability than that of the control. The FT- IR and 13C NMR analysis revealed that the structures of the modified lacquer were significantly improved by cross-linking with the hydroxymethyl groups and methylene methyl ethers of MMU. In addition, through scanning electron microscopy (SEM) characterization, it was found that the introduction of MMU can effectively improve the surface smoothness of the lacquer film.