step, while from hydrolyzed samples, spectra were recorded after
the acid hydrolysis step.
X-ray powder diffraction analyses were performed with a Philips
1820 diffractometer operated at 45 kV, 40 mA with graphitefiltered
Cu-Ka radiation. Data were acquired in a 2h scale from 5
to 40. Besides coconut fibers and nanowhiskers, commercial cellulosic
(fibrous cellulose powder CF1) and Kraft lignin samples were
also examined. Crystallinity degree was calculated from X-ray diffraction
curves by the ratio of the crystalline area to the total area.
Thermogravimetric analysis (TGA) was performed to study the
degradation characteristics of the cellulose whiskers obtained by
different treatments. The samples were heated from room temperature
to 800 C at a heating rate of 10 C/min and a nitrogen gas