Properties and characterization of biodegradable poly(lactic acid) (PLA)/poly(ethylene glycol) (PEG) and PLA/PEG/organoclay

Abstract

Poly(ethylene glycol) (PEG) was mixed at various weight percentage with biodegradable poly(lactic acid) (PLA) via direct melt compounding method. Nanocomposites of PLA/PEG, with two types of organoclay namely, cloisite 93A (C93A) and cloisite 30B (C30B) were also prepared by melt blending method. The crystallization behaviors of PLA/PEG and PLA/PEG/organoclay were studied using differential scanning calorimetry (DSC). The isothermal crystallization kinetics has been investigated using the Avrami’s equation. In PLA/PEG, the PLA crystallized first followed by crystallization of PEG during the cooling. The viscoelastic behavior of the PLA/PEG and PLA/PEG/organoclay were investigated by dynamic mechanical analysis where the nanocomposites showed higher magnitude of storage modulus. The plasticizing effect of PEG acts predominantly in the mechanical performance of PLA/PEG, which shows increased percentage elongation and impact strength in the blend. The sample with 20 wt% PEG showed optimum impact strength. Again, the nanocomposite with 3 wt% C30B exhibited better tensile strength and modulus than the sample with C93A. The characterization of fractured surface of the matrix polymer and the blend were compared through scanning electron microscopy. The rheological and compostability study of the system were further investigated.