Renewable rice straw cellulose nanofibril reinforced poly(ε-caprolactone) composite films

Abstract

In this study, cellulose nanofibrils (CNFs) fabricated from rice straw were utilized to reinforce poly(ε-caprolactone) (PCL), and the structure and properties of these CNF/PCL composite films were analyzed by morphology observation and the measurements of X-ray diffraction (XRD), differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), mechanical property and water absorption. The experimental results revealed that in PCL matrix, CNF exhibits a homogeneous distribution at low content, but shows some aggregates at high content. The incorporated CNF doesn't change the crystal type, crystallinity and melting temperature of PCL, but accelerates the crystallization of PCL due to its heterogeneous nucleating agent effect. Compared with PCL film, the CNF/PCL composite films show obvious improvement of tensile strength and Young's modulus with the increments of 7.5% at 10% CNFs and 76% at 15% CNFs respectively. However, after the CNF content exceeds 10%, the tensile strength of the composite films begins to decrease, and high loading of CNFs also causes remarkable negative influences on the thermal stability and hydrophobicity of the composite films. The straw CNFs reinforced PCL composite films can be employed in packaging and biomedical applications.