Experimental study on durability of wood–plastic composites by coupling dry–wet cycles and seawater environment

Abstract

AbstractThe durability of wood–plastic composites (WPCs) exposed to seawater dry–wet cycles were investigated. The most detrimental cycles were evaluated by the orthogonal design method. The physical properties, structural strength, chemical characteristics, and thermal stability of WPC materials under the worst seawater dry–wet (W‐SDW) cycles were described based on discoloration/water absorption/thickness swelling, hardness/impact strength, Fourier transform infrared spectra, and thermogravimetric analysis results, respectively. The results showed that the W‐SDW cycles were: immersion temperature of 60°C, immersion time of 4 h, drying temperature of 70°C, and drying time of 3 h. The exposure to W‐SDW cycles degraded the fiber–matrix interface interaction, increasing discoloration, water absorption, and thickness swelling as well as reducing hardness, impact strength, and pyrolysis temperature. The degree of degradation of the fiber and matrix is positively correlated with that of the fiber–matrix interface interaction. The analysis of the experimental phenomenon indicates that protecting the fiber–matrix interface maintains the durability of WPC materials.