In this work, the relationship between cellulose crystallinity, the influence of extractive content on lignocellulosic fiber degradation, the correlation between chemical composition and the physical properties of ten types of natural fibers were investigated by FTIR spectroscopy, X-ray diffraction and thermogravimetry techniques. The results showed that higher extractive contents associated with lower crystallinity and lower cellulose crystallite size can accelerate the degradation process and reduce the thermal stability of the lignocellulosic fibers studied. On the other hand, the thermal decomposition of natural fibers is shifted to higher temperatures with increasing the cellulose crystallinity and crystallite size. These results indicated that the cellulose crystallite size affects the thermal degradation temperature of natural fibers. This study showed that through the methods used, previous information about the structure and properties of lignocellulosic fibers can be obtained before use in composite formulations.

No abstract

In this study, the relationship between wood cellulose crystallinity, influence of extractives on wood degradation, correlation between chemical composition, and physical properties of four wood species were investigated by chemical analysis, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetry. The chemical analysis showed that Dipteryx odorata and Mezilaurus itauba (ITA) contained a higher quantity of extractives and lower quantities of holocellulose and lignin than Eucalyptus grandis (EUG) and Pinus elliottii. FTIR spectroscopy indicated that higher extractives content in ITA might be associated with more intense bands at 2920, 2850, and 1510 cm À1 . The lower values for hydrogen bond energy and hydrogen bond intensity showed that EUG contained more absorbed water than the other species. Thermogravimetry confirm that lower extractive contents leads to a better wood thermal stability. This study showed that through the methods used previous information about structure and properties of wood can be obtained before use it in composite formulations. V C 2012Wiley Periodicals, Inc. J Appl Polym Sci 126: E336-E343, 2012