Solvent and enzyme induced recrystallization of mechanically degraded hemp cellulose

The structural degradation of cellulose fibre from hemp (Cannabis Sativa L.) by a ball-milling process and the recrystallization behavior of the product were studied. A linear increase in the Brunauer-Emmett-Teller specific surface area was observed; indicating the fibre bundles were being crushed and disrupted to single fibres, which was confirmed by SEM. An increase in the milling duration gradually destroyed the crystalline structure of the cellulose fibres, observed by a reduction of the 002 plane intensity in wide angle X-ray scattering measurements. The crystalline order index calculated from the area ratio of the 002 to the 021, 10 (1) over bar and 002 planes was decreased from 65 to 36 after milling for 330 min. Subsequently the lower thermal stability of ball-milled fibre was observed from a decrease in the temperature at the maximum mass loss rate using thermogravimetry. An increase in solvent polarity, solvent-fibre ratio, agitation speed and drying rate resulted in the rearrangement of ball-milled cellulose crystalline structure to a greater order. Moreover, an increase in the BET specific surface area and the amorphous fraction improved the scouring efficiency of the ball-milled cellulose using the pectate lyase enzyme (EC. 4.2.2.2).