Improvement of UV resistance and mechanism in polypropylene wax on wood surface through maleic anhydride and β-nucleating agent modification

Abstract

In China, beeswax is commonly used to protect hardwood surfaces through hot waxing, and is widely utilized in wood furniture and buildings. However, beeswax, with its low melting point and high cost, is prone to being destroyed and falling off, and has a short-term protective effect on wood under ultraviolet (UV) light. Polypropylene wax (PPW), with its low cost and high melting point, holds potential for application in wood protection. The introduction of maleic anhydride enhanced the combination of PPW and wood, resulting in excellent surface properties. Additionally, the β-nucleating agent (WBG-II) induced PPW to form β crystal structure, further enhancing the UV barrier property of the wax coating. After UV irradiation, the surface properties of the hot-waxed wood using the modified polypropylene wax exhibited minimal changes, including color, adhesion, hydrophobicity, and surface roughness. The chemical structure, crystalline structure, and surface morphology were analyzed by FTIR, XRD, and SEM to reveal the photodegradation mechanism of the surface wax coating. The results demonstrated that the co-modification of polypropylene wax by maleic anhydride and WBG-II has a positive effect on the long-term protection of wood substrate, providing a reference for wood protection, particularly for dark and precious wood, and helping to reduce deforestation.