| Abstract:In order to speed up the penetration of acid to cellulose, increase the average rate of acid hydrolysis, thus reduce the amount of acid used and shorten the reaction time in preparation of microcrystalline cellulose, softwood dissolving pulp was used as raw material and pretreated by Valley beating. The effect of Valley beating on the quality of microcrystalline cellulose produced by acid hydrolysis was studied. The results showed that compared with raw materials without beating, the average particle size of MCC decreased gradually with the increase of beating degree, when the beating degree was 53°SR, the average particle size decreased from 52.116 μm to 38.675 μm, the particle size distribution was more concentrated, and the crystallinity of MCC did not change much. The conditions of Valley beating and acid hydrolysis were optimized by using response surface method, the particle size and crystallinity of MCC prepared basically remained the same, the amount of acid used was reduced by 16.67%, and the reaction time was shortened by 42.86%.It indicated that the pretreatment of Valley beating could improve the accessibility of acid to cellulose, achieve effective control of MCC particle size while reducing acid hydrolysis pollutant load. |
