Abstract: Composites of poly(vinyl alcohol) (PVA) and upper-section straw powder were prepared by hot pressing. The effects of PVA content, pressing temperature, and pressing time on the tensile properties, bending properties, and hardness of the composites were studied. Scanning electron microscopy was used to characterize the microstructure of the composites. It showed that the tensile strength of the composites obviously increased with increasing content of PVA. If hot pressing temperature and hot pressing time were appropriately increased, the tensile strength of the composites would be improved but the rate of increase was moderate. The hardness of the composites showed non-uniform characteristics and was not affected obviously by material ratio and processing conditions. The tensile strength reached the highest value of 7.54 MPa, when the content of PVA was 40 % and hot pressing was carried out at 140 ℃ for 14 min.

Key words: mechanical property, composite, straw, preparation, poly(vinyl alcohol)