Studies on thermal and degradation kinetics of cellulose micro/nanoparticle filled polylactic acid (PLA) based nanocomposites

Abstract

The aim of this work is to understand the effect of concentration of plasticizer, particle size and wt% of nanoparticles on nanocomposites by fabricating poly lactic acid (PLA) based bio-nanocomposites. The bio-nanocomposites were prepared by a solution casting method with PLA as the matrix, chloroform as solvent and poly ethylene glycol (PEG) as plasticizer. Microcrystalline cellulose (MCC) and cellulose nanocrystal (CNC) were used as reinforcements in 1, 3 and 5 wt% to modify the properties of the bio-nanocomposite. The degradation kinetics of the PLA based composites were determined by using the Coats-Redfern equation over the range of 0-5 wt% of MCC and CNC. Fabricated PLA based composite films were analyzed by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and field emission scanning electron microscopy (FE-SEM). The analyses showed that the amount of PEG, MCC and CNC affected the degree of crystallinity. DSC results showed that the MCC/CNC content level affected the degree of crystallinity compared to neat PLA. The FTIR showed a free hydroxyl group (−OH) present in the system. The TGA analysis showed that the PLA/MCC3%/ PEG 10% composition had the highest stability compared to the other compositions but less than neat PLA.