Strengthening and toughening of TEMPO-oxidized cellulose nanofibers/polymers composite films based on hydrogen bonding interactions

TEMPO-oxidized cellulose nanofibers (TOCNs) derived from the TEMPO-mediated oxidation of macro cellulose fibers have plentiful hydroxyls (-OH) and carboxyl anions (-COO−) on their surface, which are prone to form strong hydrogen bonding (HB) interactions with HB acceptor/donor contained polymers. In this work, polyvinylpyrrolidone (PVP), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyacrylic acid (PAA), and carboxymethyl cellulose (CMC) were selected as HB acceptor/donor to fabricate composite films with TOCNs, and the influences of HB interactions on the mechanical properties of the as-prepared composites were thoroughly analyzed. It was found that polymers containing both HB donor and acceptor have better mechanical enhancement abilities than the polymer only containing HB acceptor. Among the selected polymers, TOCN/PAA shows the best comprehensive mechanical properties with a stress of 185.5 MPa, a strain of 7.62%, and a toughness of 9.54 MJ m−3, which are 79.7%, 67.5%, and 223.4% higher than the pure TOCN film, respectively.