50 Green Composites from Natural Resources
and selectivity obtain partially hydrolyzed cellulose, depending on the hydrolysis
time. Amorphous cellulose and defect crystals are hydrolyzed rst since diffusion
of the acid is faster. The more perfect crystals resist diffusion of the acid and the
reaction is limited. After a selected time, the remaining cellulose is washed free of
acid. The process may result in half the original cellulose being hydrolyzed; however,
the remaining cellulose consists of the more perfect crystals.
Cellulose with larger crystal size has been found to be more resistant to thermal
degradation, although activation energy for degradation was constant (Kim et al.
2010). The results indicate that crystal size determines ...