Morphology, healing and mechanical performance of nanofibrillated cellulose reinforced poly(ε-caprolactone)/epoxy composites

In this study, nanofibrillated cellulose (NFC) reinforced poly(ε-caprolactone) (PCL)/epoxy composites were fabricated by a combination method of solvent exchange and melt mixing. Effects of NFC incorporation on morphology, healing capability and mechanical properties of PCL/epoxy systems were investigated. Domain size of the separated phases was reduced and the continuity of PCL-rich phase was increased with NFC addition. Both healing efficiency and mechanical properties were improved due to the uniform distribution and bridging effect of NFC within the polymer matrix. Upon the addition of merely 0.2 wt% of NFC, the healing efficiency was increased by about 26% and simultaneously tensile strength, elongating at break and impact strength were improved by about 27%, 38% and 38%, respectively. Additionally, glass transition temperature of the epoxy phase in the composite was increased by about 12.8 °C.