Structure and thermal properties of natural colored cottons and bombax cotton.

Chemical compositions, crystalline structures and thermal properties of bombax cotton and natural colored cottons including laurel green, bottle green and brown cotton were investigated by chemical analysis, SEM, IR spectra and X-ray diffraction. The results showed that the crystallinity and crystallite sizes of laurel green cotton were lower than those of bottle green cotton because of the excess content of suberin in the former. The crystallinity of brown cotton was similar to that of white cotton, and bombax cotton had the lowest crystallinity but its crystallite orientation was the highest. Thermal property of bottle green cotton was the most stable, whose decomposition temperature was higher of 30°C than that of common white cotton because of its higher lignin content, and bombax cotton had the lowest thermal degradation temperature. But bottle green cotton reached the highest decomposition speed and made decomposition finish within a very short time, and bombax cotton was just the reverse. [ABSTRACT FROM AUTHOR]