Cellulase pretreatment has attracted much attention in the preparation of microfibrillated cellulose due to its environmental friendliness. In this study

different concentrations of cellulase and high pressure jet treatment were used to prepare microfibrillated cellulose. The results show that the diameter of cellulose fibrils was decreased from several or tens of microns to tens or hundreds of nanometers and crystal structure was not changed after cellulase pretreatment and high pressure jet treatment. The particle size analysis shows that the cellulose micronizing level based on 1% (w/w ) cellulase pretreatment and high pressure jet treatment is higher. With the increase of enzyme concentration from 0.1% to 0.5%

the viscosity of cellulose aqueous dispersion increased

and the thermal stability and the tensile properties of cellulose films were enhanced. The average tensile strength of the films treated with 0.5% enzyme and high pressure jet treatment is 18.74MPa. The tensile properties of the films treated with 1% cellulase pretreatment and high pressure jet treatment had little change. And the average tensile strength is 18.99MPa

the average elongation at break is 8.74%

and the average elastic modulus is 293.8MPa.