Polylactic acid/polycaprolactone nanocomposite

Abstract

This article investigates the performance of polylactic acid (PLA)/polycaprolactone (PCL)/montmorillonite (MMT) nanocomposites toughened with metallocene-catalyzed linear low-density polyethylene (mLLDPE), in terms of mechanical, thermal, and morphological properties. All the results were compared and the influence of MMT and mLLDPE on the final properties was observed and reported. mLLDPE decreased the modulus and the strength of PLA/PCL and its nanocomposites due to its inherent lower rigidity compared to PLA/PCL nanocomposites. Moreover, incorporation of clay significantly increased mechanical and thermal stability of the nanocomposites. Scanning electron microscopic images confirmed that MMT acted as a compatibilizer, whereas it reduced the size of the droplets. It has been suggested that improvements in properties are related to good dispersion of clays within the matrix. However, further addition of MMT beyond 2 parts per hundred (phr) level decreases all the properties of PLA/PCL/mLLDPE/MMT nanocomposites. X-Ray diffraction patterns were used to discover the reason of reduction in the properties of PLA/PCL/mLLDPE/MMT at 4 phr. It was revealed that mLLDPE-toughened blends have intercalated structure below 4 phr MMT content as the interlayer spacing decreased at 4 phr MMT.