Acetylation and stepwise solvent-exchange to modify hydrophilic cellulose whiskers to polychloroprene-compatible nanofiller

The acetylation of cellulose nanofiber (CNF) introduced hydrophobicity to the surface making it compatible with non-polar matrix, and also making it an effective nanofiller for polychloroprene (PCR) composite. The CNF was extracted from oil palm empty fruit bunches. Previously, CNF was dispersed in water, and this water was subsequently substituted with N,N-dimethylacetamide, in which CNF was acetylated by acetic anhydride with a pyridine catalyst. IR spectroscopy revealed that the acetylation extent was controllable by the reaction time. After the reaction, the DMAc was replaced by dichloromethane, and finally mixed with PCR. The CNF–PCR mixture was cast and composite film was formed at room temperature. Structural analysis and mechanical tests indicated that acetylation treatment made CNF compatible with PCR, and that nano-dispersed CNF raised the mechanical strength of the PCR–CNF nanocomposite.