Effects of microcrystalline cellulose surface modification on the mechanical and thermal properties of polylactic acid composite films

Abstract

ABSTRACT Microcrystalline cellulose (MCC), extracted from distiller’s grains by nitric acid-ethanol hydrolysis, was prepared for PLA composite films by solution casting. MCC based on the optimum comparison was characterised by particle size analysis and scanning electron microscopy. The results show that the ultrasound combined sulphonation treatment was remarkable for the surface structure of MCC, compared with that modified by sulphonation and ultrasound methods. The MCC/PLA composite films were analysed using Fourier-transform infrared spectroscopy (FT-IR), mechanical properties and thermal resistance. The results show that the properties and performance of MCC/PLA composite film using ultrasound combined sulphonation treatment are obviously better than those of modified films by other methods. For the modified MCC/PLA composite film by sulphonation and ultrasound methods, the FT-IR analysis carried out a large number of hydroxyl groups that are hydrolysed, the tensile strength upped to 505.24 MPa and the thermal-decomposed temperature increased to 320°C from 260°C. The modified MCC would be a beneficial filling material for the properties of PLA composites.