Seawater Degradation Resistance of Straw Fiber-reinforced Polyvinyl Chloride Composites

To investigate the effect of seawater degradation on the mechanical, wear, and thermal properties of plant fiber-reinforced polymer composites, the seawater immersion test was performed on four types of straw fiber (wheat straw (WS), rice straw (RS), corn straw (CS), and sorghum straw (SS))-reinforced polyvinyl chloride (PVC) composites. The results revealed that seawater immersion would result in poor mechanical, wear, and thermal properties, and lower two-phase bonding quality, thermal mass loss, and thermal residual mass, as well as more serious abrasive wear. The SS/PVC and CS/PVC composites had the highest and lowest seawater degradation resistance, respectively. After 12 d seawater immersion, the tensile strength of the SS/PVC and CS/PVC composites decreased from 17.3 to 9.7 MPa and from 12.3 to 7.2 MPa, respectively; and the flexural strength of the SS/PVC and CS/PVC composites decreased from 34.2 to 20.1 MPa and from 28.0 to 15.3 MPa, respectively. However, the friction coefficient of the SS/PVC and CS/PVC composites increased from 0.21 to 0.27 and from 0.24 to 0.30, respectively; and the specific wear rate of the SS/PVC and CS/PVC composites increased from 0.73 x 10(-5) mm(3)/N center dot m to 21.7 x 10(-5) mm(3)/N center dot m and from 1.77 x 10(-5) to 28.3 x 10(-5) mm(3)/N center dot m.