Development and characterisation of packaging film from Napier cellulose nanowhisker reinforced polylactic acid (PLA) bionanocomposites

A packaging material that is environment-friendly with excellent mechanical and physicochemical properties, biodegradable and ultraviolet (UV) protection and thermal stability was prepared to reduce plastic waste. Six different concentrations of Pennisetum purpureum/Napier cellulose nanowhiskers (NWCs) (i.e. 0, 0.5, 1.0, 1.5, 2.0, and 3.0 wt%) were used to reinforce polylactic acid (PLA) by a solvent casting method. The resulting bionanocomposite film samples were characterised in terms of their morphology, chemical structure, crystallinity, thermal degradation and stability, light transmittance, water absorption, biodegradability, and physical and mechanical properties. Field-emission scanning electron microscopy showed the excellent dispersion of NWC in the PLA matrix occurred with NWC concentrations of 0.5-1.5 wt%. All the bionanocomposite film samples exhibited good thermal stability at approximately 343-359 °C. The highest water absorption was 1.94%. The lowest transparency at λ₈₀₀ was 16.16% for the PLA/3.0% NWC bionanocomposite film, which also has the lowest UVA and UVB transmittance of 7.49% and 4.02%, respectively, making it suitable for packaging materials. The PLA/1.0% NWC film exhibited the highest crystallinity of 50.09% and high tensile strength and tensile modulus of 21.22 MPa and 11.35 MPa, respectively.

Composite of PLA Nanofiber and Hexadecyl Trimethyl-Ammonium Chloride-Modified Montmorillonite Clay: Fabrication and Morphology

Our research aim is to develop a new composite material via electrospinning and dip coating methodology. Among bioabsorbable polymers, Polylactic acid (PLA) is viewed as a suitable base material for biomedical usages such as drug delivery and wound dressing. Additionally, these bioabsorbable materials can be used for filtration applications in terms of antibacterial activity the integration of hexadecyl trimethyl ammonium chloride-modified montmorillonite (CTAC-MMT) into PLA fibers would improve mechanical and absorption properties of the PLA fibers. This research aimed to investigated a new method of combining electrospun PLA with dip coating of CTAC-MMT solution. Precisely, electrospun PLA nanofibers were treated with methanol and dipped in a CTAC-MMT suspension. The resultant layer composite of PLA nanofibers and CTAC-MMT was then characterized by elemental analysis. For material characterization and morphological structure analysis, we performed FTIR, SEM-EDS, XPS, DSC, and X-ray diffraction. Through mechanical testing and contact angle measurements, it was found that CTAC-MMT shows a slight improvement in mechanical and absorption properties. Results of characterization techniques have shown that CTAC-MMT can be used as a good filler for composites processed through the dip-coating method. Moreover, results also showed that the diameter of microfibers is affected by concentrations of PLA.