Addition of Organo-Modified Nanoclay for Tuning the Microstructure, Thermal Stability, and Biodegradability of Poly(lactic acid)/Polycarbonate Immiscible Blends

• Published in: Polymer science. Series A, Chemistry, physics Chemistry, physics, 2022-10, Vol.64 (5), p.519-531
• Main Authors: Nadjat Chelghoum, Mayouf, Imane, Larous, Ali, Guessoum, Melia, Fois, Magali, Haddaoui, Nacerddine
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Composites; Environmental Sciences; Polymer Sciences
• ISSN: 0965-545X; 1555-6107
• DOI: 10.1134/S0965545X22700225

Poly(lactic acid) (PLA)/polycarbonate (PC) blends and composites were compared to investigate the effects of matrix composition and nanoclay content on the materials properties. The composites were prepared by incorporating 1, 3, and 5 wt % of organo-modified montmorillonite (MMT) and varying the PC content from 10 to 30 and 50%. The formulations were melt blended then subjected to many investigations such as thermal, structural and morphological analyses and to biodegradation. Microstructure observation revealed a significant morphology refinement of the mixtures forming the composites matrices and pointed out an optimal dispersion of PC domains into the PLA phase. This could be assigned to the fact that the interactions evolved between PC chains and MMT tactoids contribute in creating a barrier against PC domains coalescence, thus reducing their size and refining the morphology. As a result, the thermal and thermo-mechanical analyses of PLA/PC/MMT composites unveiled notable variations on the crystallization and viscoelastic properties depending on the matrix composition and MMT content. Also, TGA and biodegradability assessment by soil burial method emphasized the crucial contribution of MMT in increasing the composites thermal stability and promoting their biodegradation.