Thermal degradation behaviour of multi-walled carbon nanotube-reinforced poly(L-lactide) nanocomposites

BACKGROUND: Polymer/multi-walled carbon nanotube (MWCNT) composites are one of the most promising alternatives to conventional polymer composites filled with micrometre-sized fillers. This approach can also be applied for the improvement of mechanical properties and thermal stability of biodegradable aliphatic polyesters, such as poly(L-lactide) (PLLA), which have been receiving increasing attention due to environmental concerns. Thermal degradation behaviour provides useful information for the determination of the optimum processing conditions and for identification of potential applications of final products. RESULTS: The PLLA/MWCNT composites investigated showed a higher thermal degradation peak temperature and onset temperature of degradation along with a higher amount of residue at the completion of degradation than neat PLLA. Moreover, PLLA/MWCNT composites with a greater MWCNT content showed higher activation energy of thermal degradation than those with a lower MWCNT loading, which confirmed the positive effect of MWCNT incorporation on the enhancement of PLLA thermal stability. CONCLUSION: This study explored the thermal degradation behaviour of PLLA/MWCNT composites by observing the weight loss, molecular weight and mechanical properties during non-isothermal and isothermal degradation. The incorporation of MWCNTs into the PLLA matrix enhanced considerably the mechanical properties and thermal stability. (C) 2009 Society of Chemical Industry