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.

In this study, formaldehyde-urea prepolymer (FUP) were synthesized, which were used to modify the raw lacquer (RL) and this composition named LF, while the basic properties of the RL were tested. Thermal gravimetric (TG) analysis and scanning electron microscopy (SEM) were used to analyze the degradative characteristics and the surface morphology of RL before and after modification. The result indicated that FUP can significantly improve the performance of RL. The drying time of the LF is significantly shortened, the gloss, the pencil hardness, and the impact performance are significantly enhanced at the same time. TG analysis and thermal decomposition kinetics analysis illustrated that the thermal stability and the activation energy of LF2 were stronger than that of RL. In addition, SEM analysis illustrated that the surface smoothness of RL were also improved.

In this study, formaldehyde-urea prepolymer (FUP) were synthesized, which were used to modify the raw lacquer (RL), while the basic properties of the RL were tested. Thermal gravimetric analysis and scanning electron microscopy were used to analyze the degradative characteristics and the surface morphology of RL before and after modification. The result indicated that FUP can significantly improve the performance of RL. The drying time of the modifying RL is significantly shortened the gloss, the pencil hardness, and the impact performance are also significantly enhanced at the same time. TG analysis and thermal decomposition kinetics analysis illustrated that the thermal stability and the activation energy of LF2 were stronger than that of RL. In addition, scanning electron microscopy analysis illustrated that the surface smoothness of RL were also improved.