Cellulose nanofiber-reinforced polycaprolactone/polypropylene hybrid nanocomposite

In this study, cellulose nanofiber (CNF) production was attempted by using a batch-type kneader with six twin-screw elements. Screw elements were twisted with 22.5° to generate a high shearing force. The obtained fibrillated products showed a nanoscale morphology, indicating the effectiveness of using a batch-type kneader. For better CNF dispersion in the polymer matrix, CNFs were first distributed in polycaprolactone (PCL) with a low melting temperature to avoid the vaporization of water in a CNF-water solution and then this composite was further mixed with polypropylene (PP) at 180 °C. The distributions of the PCL domain and CNF in PP were improved by the addition of maleic anhydride-grafted-PP. The elastic modulus of the hybrid composite thus obtained was increased by the addition of only 1% CNF. The crystallization of both polymers in the composites started at a higher temperature than in neat polymers during cooling DSC scanning.