Modelling of gas permeability property of poly (lactic acid)/ poly (butylene succinate) (PLA/PBS) nanocomposites

Gas permeability and morphological properties of nanocomposites prepared with the mixing of poly (lactic acid) (PLA), poly (butylene succinate) (PBS) and organically modified layered silicate were investigated. Composition of PLA and PBS polymers were fixed as 80% and 20% by weight for all the nanocomposites. Nanocomposites containing 1, 3, 5, 7 and 10 wt% of C30BX clay were prepared to investigate the effect of clay content on morphological, rheological, thermal and gas barrier properties of these nanocomposites. From morphological studies using wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM), nanocomposite having 1 wt% of clay was considered to attain mixed morphology of intercalated and exfoliated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and more than 3 wt% of clay. However, the average particle size of the dispersed phase PBS reduced significantly from 7 ìm to 30-40 nm with the addition of clay in the blend. Oxygen barrier property improved significantly as compared to water vapour. PLA/PBS/C30BX nanocomposites validated the Bharadwaj model for gas barrier properties prediction up to 3 wt% of clay contents only while for nanocomposites of higher clay contents this model was invalid due to the clusters and agglomerates formation