Performance Analysis of Plant Shells/PVC Composites under Corrosion and Aging Conditions

Abstract

To make full use of plant shell fibers (rice husk, walnut shell, chestnut shell), three kinds of wood-plastic composites of plant shell fibers and polyvinyl chloride (PVC) were prepared. X-ray diffraction analysis was carried out on three kinds of plant shell fibers to test their crystallinity. The aging process of the composites was conducted under 2 different conditions. One was artificial seawater immersion and xenon lamp irradiation, and the other one was deionized water spray and xenon lamp irradiation. The mechanical properties (tensile strength, flexural strength, impact strength), changes in color, water absorption, Fourier transform infrared spectroscopy (FTIR), and microstructures of the composites before and after the two aging experiments were analyzed. The results showed that the chestnut shell had the highest crystallinity, which was 42%. The chestnut shell/PVC composites had the strongest interface bonding, the least internal defects, and the best general mechanical properties among the three composites. Its tensile strength, bending strength and impact strength were 23.81 MPa, 34.12 MPa, and 4.32 KJ·m−2, respectively. Comparing the two aging conditions, artificial seawater immersion and xenon lamp irradiation destroyed the quality of the combination of plant shell fibers and PVC, making the internal defects of the composites increase. This made the water absorption ability and changes in the color of the composites more obvious and led to a great decrease in the mechanical properties. The general mechanical properties of the chestnut shell/PVC composites were the best, but their water absorption ability changed more obviously.