| Abstract:Microfibrillarized cellulose (MFC) was prepared from six different fiber raw materials (including hardwood bleached kraft pulp, bamboo bleached kraft pulp, softwood bleached kraft pulp, cotton linter pulp, softwood bleached chemimechanical pulp, and corncob cellulose) by carboxyethylation pretreatment combined with mechanical grinding, and then MFC films were formed by rod coating method. The effects of carboxyl content, grinding times and type of raw materials on the properties of MFC and its films were discussed. The results showed that the water retention value of MFC increased from 98% to 538% and the porosity of MFC film decreased from 37% to 19% with the increase of carboxyl content in the pretreated hardwood bleached kraft pulp. When the carboxyl content was 0.8 mmol/g, the tensile strength of MFC film was the highest, reaching 53 MPa. In addition, with the increase of grinding times, the degree of fibrillation of MFC increased, and the strength of MFC film increased first and seached a maximum value of 75 MPa then decreased. Under the optimum conditions of carboxyethylation pretreatment and grinding times, among the MFC membranes prepared from six different raw materials, the strength of MFC membranes obtained from bleached bamboo kraft pulp was the highest, up to 84 MPa, with a porosity of 25%. |
