Heterogeneous hydrolysis of three cellulose species, Cotton linter (C), NBSP (P) and Regenerated cellulose (R) having a different degree of crystallinity, and homogeneous hydrolysis of P sample were carried out using sulfuric acid. The following results were obtained.
The rate of hydrolysis was greater in such a sample with a low crystallinity, and it was in the order of C<P<R sample. When hydrolyzed with 3N H
2SO
4 at 100°C, _??_, _??_and Polydispersity (
PD) initially decreased rapidly and then became constant. The leveling off values of _??_, _??_and
PD were about 700, 200, and 3.5, respectively (C, P sample). The corresponding values for R sample were about 50, 40 and 1.2. In case of homogeneous system of P sample after 30min hydrolysis, _??_, _??_and
PD were about 140, 80 and 1.8, respectively. _??_and _??_decreased further with hydrolysis time.
The yield of sugar was very low in the heterogeneous system, but high in the homogeneous system (attained about 100% at 23°C for 7hr). In case of the homogeneous hydrolysis of P sample (72% H
2SO
4, 23°C, 7hr), the yields of glucose, cellobiose and cellotriose were 40.1, 16.8 and 10.0%, respectively. Furthermore, when P sample was hydrolyzed with 72% H
2SO
4 at 23°C for 5hr (primary), diluted to 1% and hydrolyzed again at 60°C for lhr (secondary), the yields of glucose, cellobiose and cellotriose increased to 45.7, 32.7 and 14.1%, respectively.
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