Abstract: To improve the mechanical properties of sodium carboxymethyl cellulose (CMC) films, 2,2,6,6-tetramethyl-1-piperidinyloxy-oxidized cellulose nanofibrils (TOCNs) were incorporated into CMC films to enhance the tensile strength, and cationic polyacrylamide (CPAM) was also added to increase the elongation at break by taking advantage of the electrostatic interaction between the cations produced electrolytically from it and the carboxylate ions formed by TOCNs and CMC in aqueous solutions. Biodegradable blend films with good tensile strength and toughness were obtained. The blend film with an m (CMC):m (TOCNs):m (CPAM) ratio of 50:10:1 exhibited an increase in tensile strength of 177% and an increase in elongation at break of 36% as compared with pure CMC film, accompanied by an increase in light transmittance and thermal stability but a slight decrease in oxygen resistance. Our results showed that the tensile strength and thermal stability of CMC film could be improved obviously by adding TOCNs and the elongation at break and light transmittance could be improved obviously by adding CPAM. There were interactions and good compatibility among the three agents, contributing to improved physical and chemical properties of CMC film.

Key words: 2,2,6,6-tetramethyl-1-piperidinyloxy-oxidized cellulose nanofibrils, cationic polyacrylamide, enhancement, electrostatic interactions, biodegradable material