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Melt blending of polylactic acid (PLA) and linear low density polyethylene (LLDPE) was performed to investigate the effects of LLDPE loadings on the morphology, mechanical and thermal properties of PLA/LLDPE blends. LLDPE was blended with PLA from 5—15 wt% and prepared by counterrotating twin-screw extruder followed by injection molding into test samples. The mechanical properties of the blends were assessed through tensile, flexural and impact testings while thermal properties were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis. Scanning electron microscope was used to study the dispersion and particle size of LLDPE in PLA matrix. The impact strength of PLA improved by 53% with addition of 10 wt% LLDPE. However, the tensile modulus and strength, and elongation at break of PLA/LLDPE blends decreased with increasing weight ratio of LLDPE. Similarly, flexural modulus and strength also dropped with addition of LLDPE. DSC results showed that glass transition temperature (Tg) and crystallinity (X c) of PLA increased with blending of LLDPE. The LLDPE particles size was seen to increase with increasing loadings of LLDPE which explains the unexpected decrease of impact strength after 10 wt%.

The aim of present study is to develop a toughened polylactic acid/talc composite. Talc and epoxidized natural rubber (ENR-50) were compounded with polylactic acid using counterrotating twin-screw extruder followed by preparation of samples through injection molding. The effect of silane-treated talc and epoxidized natural rubber on mechanical, thermal, and morphological properties of polylactic acid was investigated. The Young′s and flexural modulus of polylactic acid improved while the impact strength values dropped with increasing talc content (20-30 wt%) indicating that talc increased the stiffness of polylactic acid with a sacrifice in toughness. Subsequently, the blending of epoxidized natural rubber (20 wt%) to polylactic acid/talc (30 wt%) revealed that the impact strength of polylactic acid/talc composites improved 448% with considerable drop in Young's and flexural modulus. Polylactic acid/talc/epoxidized natural rubber composite contains 60% polylactic acid, 30 wt% talc, and 10 wt% ENR display optimum stiffness and impact strength. Scanning electron micrographs demonstrates that talc agglomerates at higher loadings. Thermogravimetric anlaysis indicated that thermal stability of polylactic acid/talc composite was reduced by the addition of epoxidized natural rubber due to increasing talc agglomeration.

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This study presents the preparation of regenerated cellulose (RC)/graphene nanoplatelets (GNPs) nanocomposites via room temperature ionic liquid, 1-ethyl-3-methylimidazolium acetate (EMIMAc) using solution casting method. The thermal stability, gas permeability, water absorption and mechanical properties of the films were studied. The synthesized nanocomposite films were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The T20 decomposition temperature of regenerated cellulose improved with the addition of graphene nanoplatelets up to 5 wt%. The tensile strength and Young's modulus of RC films improved by 34 and 56%, respectively with the addition of 3 wt% GNPs. The nanocomposite films exhibited improved oxygen and carbon dioxide gas barrier properties and water absorption resistance compared to RC. XRD and SEM results showed good interaction between RC and GNPs and well dispersion of graphene nanoplatelets in regenerated cellulose. The FTIR spectra showed that the addition of GNPs in RC did not result in any noticeable change in its chemical structure.

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