Preparation of microcrystalline cellulose from dissolving cellulose by cryo-crushing and acid hydrolysis

An interesting method in the preparation of microcrystalline cellulose (MCC) from dissolving cellulose by cryo-crushing, followed by acid hydrolysis is presented in this research. Dissolving cellulose with high cellulose content (more than 90 wt.%) was frozen with liquid nitrogen, after that the frozen pulp was milled. This experimental result showed that an average diameter of cellulose fiber was reduced from 121.11 μm to 87.51 μm and a specific surface area was increasing from 161.13 m2/kg to 184.97 m2/kg. In hydrolysis process, sulfuric acid was selected to remove an amorphous region in cellulose fibrils and to introduce sulfate groups to form stable suspensions in organic media. This hydrolysis result demonstrated that MCC had an average diameter of 14.47 μm and a specific surface area of 427 m2/kg. The morphology of MCC was observed by optical microscopy.