Mechanical and Wear Properties of Sisal Fiber Cellulose Microcrystal Reinforced Unsaturated Polyester Composites

In this paper, sisal fiber cellulose microcrystal (SFCM) was prepared by the sulfate pulping method, and sisal fiber cellulose microcrystal/unsaturated polyester (SFCM/UP) in situ resin was polymerized. Furthermore, the SFCM/UP composite was prepared by rolling and molding techniques. Effects of SFCM content on mechanical and wear properties of the UP composites were studied. Structure and properties of the in situ SFCM/UP resin and its composites were characterized by using Fourier transform infrared, polarized optical microscopy, thermogravimetric analysis, scanning electron microscopy, and other methods. The results showed that the addition of SFCM by in situ polymerization significantly improves the thermal stability of UP: The decomposition temperature (T-d5) of SFCM/UP in situ resin, at thermal weight loss of 5%, is increased by 16 degrees C compared to that of the pure UP resin. On a condition that the SFCM content was 2%, the impact strength, flexural strength, and flexural modulus of SFCM/UP composites are higher than those of UP composites by 41.08%, 52.52%, and 32.31%, respectively. Moreover, the addition of SFCM significantly enhances the wear properties of unsaturated polyester composite at 200 degrees C; the volume wear rate of SFCM/UP composite is lower than that of UP composites by 64%, indicating SFCM could significantly strengthen and toughen UP composites.