Evalution of surface activity of hydrophobic modified nanocrystalline cellulose

Nanocrystalline cellulose (NCC) prepared via sulfuric acid hydrolysis was used as raw material. The nanocrystalline cellulose was graft-modified by long-chain fatty acids including lauric acid, palmitic acid, and stearic acid in a FeSO4/H2O2 oxidation–reduction system at low temperature. Modified nanocrystalline cellulose (MNCC) was obtained through above process. Crystalline structure and microstructure of the MNCC were analyzed and characterized. To explore the surface activities of the MNCC, contact angle, surface tension, critical micelle concentration (CMC) and hydrophile–lipophile balance (HLB) values were tested. Results showed that water contact angles of lauric acid-, palmitic acid-, and stearic acid-nanocrystalline cellulose were 79.3°, 82.5° and 84.8°, and HLB values were 15.78, 16.29 and 16.81, respectively. The CMC of the MNCC was 12.5 mg/L. The MNCC had good hydrophilic and lipophilic properties. It was a kind of non-ionic natural macromolecule surfactants and could replace traditional surfactants as emulsifiers and solubilizers.