New insights into the material chemistry of polycaprolactone-grafted cellulose nanofibrils/polyurethane nanocomposites

Polycaprolactone (PCL) was grafted to TEMPO-oxidized nanocellulose (TONCs) through a classical ring-opening polymerization reaction mediated by the surface TONC hydroxyl and carboxyl groups. The PCL increased the thermal stability and hydrophobicity without compromising the crystallinity. When TONCs and PCL-grafted TONCs (PTONC) were compared with respect to their perfusion within a segmented polyurethane matrix (CLPU), PTONC dispersed far better as evidenced by increased storage modulus and Young’s modulus. The mechanical strength of the PTONC nanocomposites was nearly that of unmodified TONCs while at a low content (