Longchao Ma,Haozhe Peng,Xinzhou Wang,Liang Chen,Shengfeng Mao,Yanjun Li
The surface properties of melamine-urea-formaldehyde (MUF) impregnated paper decorative panels are unsatisfactory, characterized by brittle surfaces, poor abrasion resistance , and limited flame retardancy. A modification was introduced to the MUF resin by incorporating a blend of polyelectrolyte complex polyethyleneimine (PEI)-phytic acid (PA) and Nano-Al 2 O 3 with the aim of enhancing the surface properties of the decorative panel. The modified resin underwent characterization, and subsequent analyses were conducted to investigate the properties of both the modified impregnated paper and the decorative panel. The results showed that the thermal stability of the modified resin was improved with a curing temperature of 124 °C. In comparison to the control, the modified impregnated paper showed an increase of 146.0 % in tensile strength and 154.5 % in elongation at break. The improved toughness of the modified MUF-impregnated paper resulted in a notable upsurge in both surface bond strength and cracking resistance of the decorative panel. The combustion test results indicated that the modified impregnated had a LOI value of 40.0 % and self-extinguishing behavior. In addition, due to the inclusion of Nano-Al 2 O 3 , the decorative panel exhibited a low abrasion value of only 14.1 mg/100r. Overall, the technology proposed in this study can improve the surface properties of decorative panels, increase their added value, and provide a new strategy for modifying MUF resin in the impregnated paper-decorated wood-based panels industry and for researchers.
Melamine–formaldehyde (MF) resin-impregnated paper-decorated panels are prone to surface cracking, which can be reduced by changing the brittle structure of the MF resin. To increase the curing degree and toughness of the resin, a hexamethylene diisocyanate trimer blocked with methyl ethyl ketoxime (ME-HDI-tri) was used as a temperature-responsive crosslinker. This latent crosslinking agent only worked above 120 °C, which prevented it from participating in cross-linking reactions during the preparation of the impregnated paper. The chemical structures of the modified MF resins (ME-HDI-tri-MF) were characterized by Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors of the MF resins were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA). Impregnated paper was prepared with ME-HDI-tri-MF, and its tensile strength and elongation at break were tested. Blockboard was prepared with ME-HDI-tri-MF, and its cracking and corrosion resistance were tested. The absorption peak of the methylene chain was observed in the FTIR spectrum of ME-HDI-tri-MF after curing, which indicated that ME-HDI-tri participated in the curing reaction of the MF resin. With the addition of ME-HDI-tri 5 %, the curing temperature of the MF resin decreased from 142 °C to 130 °C, and the ultimate tensile stress and elongation at break of the modified impregnated paper increased by 97.70 % and 86.25 %, respectively. The cracking and corrosion resistance of the decorated panel prepared with ME-HDI-tri-MF were also improved. After adding 3 % ME-HDI-tri, the surface cracking of the decorated panels was prevented, which extended the service life and broadened the application range of the decorated panels.
危险品化学品经营许可证（带存储）