Poly(lactic acid)/Poly(ethylene glycol) Polymer Nanocomposites: Effects of Graphene Nanoplatelets

Abstract

Graphene nanoplatelets (xGnP) were investigated as a novel nano-reinforcement filler in poly(lactic acid)(PLA)/poly(ethylene glycol)(PEG) blends by the melt blending method. PLA was first plasticized by PEG in order to improve its flexibility and thereby overcome its problem of brittleness. Then, xGnP was incorporated into the PLA/PEG blend. The prepared nanocomposites exhibited a significant improvement in tensile properties at a low xGnP loading. The tensile properties demonstrated the addition of 0.3 wt% of xGnP led to an increase of up to 32.7%, 69.5% and 21.9% in tensile strength, tensile modulus and elongation at break of the nanocomposites respectively, compared to PLA/PEG blend. X-ray diffraction (XRD) patterns showed the presence of a peak around 26.5○ in PLA/PEG/xGnP nanocomposites which corresponds to the characteristic peak of xGnP. The nanocomposites also shows enhanced thermal stability compared with PLA/PEG blend in thermogravimetry analysis (TGA). The enhancement to some extent of the tensile properties of the PLA/PEG/xGnP nanocomposites can be ascribed to the homogeneous dispersion and orientation of the xGnP nanoplatelets in the polymer matrix and strong interfacial interaction between both components. The scanning electron microscopy (SEM) image of PLA/PEG/0.3 wt% xGnP displays good uniformity and more homogenous morphology. Good uniformity of composites indicates a good degree of dispersion of the xGnp and therefore results in good tensile and thermal properties.

Infrared and Raman studies on polylactide acid and polyethylene glycol-400 blend

“…Characteristic of the helical backbone vibration with CH 3 rocking mode can be found at 956 and 921 cm -1 . At 871 and 756 cm -1 , two bands that can be attributed to the amorphous and crystalline phases, respectively.Therefore [6], the reported band assignments for PEG are as follows. Hydroxyl group appears at 3446 cm -1 with broading peak, then C-O-C groups can be seen at about 1090cm -1 .…”

“…PLA has been used intensively in food and industrial packaging [4]. Surprisingly, PLA has the potential to replace conventional petroleum-based plastics such as polystyrene, polyethylene, polypropylene, polyethylene terephthalate in many disposable or short-term applications [5].Naturally, PLA has a good mechanical properties such as high strength, high Young modulus, and high biocompatibility [6].However, PLA has some drawbacks such as its ductility at ambient temperature. To improveits intrinsic properties, blending is applied using other polymer such as some plasticizers [7].…”

Effects of Graphene Nanoplatelets and Reduced Graphene Oxide on Poly(lactic acid) and Plasticized Poly(lactic acid): A Comparative Study

“…Thus, the difference of the tensile properties caused by crystallinity might be ignored. From our previous studies in plasticized PLA/xGnP nanocomposites [7,10], …”

“…However, some of its disadvantages, such as relatively poor mechanical properties and gas barrier, slow crystallization rate and low thermal stability, have limited its wider applications [6]. Therefore, polymer blending and preparation of nanocomposites have often been employed to modify the physical properties of PLA in order to extend the practical applications [7][8][9][10][11]. Various nano-reinforcement fillers, such as layered silicate clay [12], carbon nanotubes [13], and layered double hydroxide [14], are being developed and extensively studied in various polymer matrices.…”

Thermal Properties, Crystallinity, and Oxygen Permeability of Na-montmorillonite Reinforced Plasticized Poly(lactic acid) Film

“…Naturally, PLA has good mechanical properties, such as high strength, high modulus and biocompatibility [1]. However, several researchers emphasized that PLA brittleness and stiffness are limited for wide application use [2].…”