Crystallization kinetics and degradation of nanocomposites based on ternary blend of poly(L-lactic acid), poly(methyl methacrylate), and poly(ethylene oxide) with two different organoclays

Ternary polymer blends composed of poly(L-lactic acid) (PLLA), poly(methyl methacrylate) (PMMA), and poly(ethylene oxide) (PEO) is used as matrix for nanocomposites with two clays: organically modified vermiculite (OVMT) and organically modified montmorillonite (Clo10A). The addition of PMMA in PLLA/PEO blend matrix reduces the chain mobility and retards the crystallization of PLLA/PEO. The retardation effect of PMMA on PLLA/PEO blend is less pronounced with higher PEO contents. The incorporation of OVMT and Clo10A is one common strategy to improve crystallization process as well as thermal and mechanical properties. The crystallization kinetics of polymer nanocomposites was found to be well described by the Mo method. The evolution of activation energy during nonisothermal course is analyzed using isoconversional method, and the trend of activation energy variation was found to be different for each of two organoclays. Thermal stability is improved by the incorporation of organoclays, where Clo10A induces better stability than that of OVMT. Enzymatic degradation tests showed that the nanocomposites with OVMT possessed higher stability on enzymatic attack and slower degradation. (C)2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012