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The aim of this research was to prepare and characterize biocomposite films from poly(lactic acid) (PLA) with spent coffee grounds (SCG). PLA can be derived from renewable resources. The SCG component consists of cellulose, hemicellulose and coffee oil 10.98%. SCG can simultaneously act as plasticizer and filler in the composites that can enhance the mixing process. The PLA/SCG biocomposite films were processed by a twin-screw extruder and blow film extruder. They were prepared by using various SCG concentrations (0%, 5%, 7.5% and 10% of SCG). The Scanning Electron Microscopy (SEM) results showed that the PLA matrix with SCG was miscible and had the SCG was well good distributed. Elongation at break was increased, when the amount of SCG was increased, with the results of PLA and PLA/SCG 10% being 5.07% and 6.63% respectively, while hardness, brittleness and tensile strength decreased. UV-vis spectrophotometric measurement of PLA/SCG biocomposite films showed a considerable reduction in transmission of all UV wavelengths (UV-A, -B and -C) and visible light with increasing SCG content. Hence, in this research, SCG can be used as filler in PLA films in order to produce biodegradable films and developed as agricultural film products. The PLA/SCG biocomposite films have shown good properties and are environmentally friendly.

Ternary-blended, melt-blown films of polylactide (PLA), polycaprolactone (PCL) and cellulose acetate butyrate (CAB) were prepared from preliminary miscibility data using a rapid screening method and optical ternary phase diagram (presented as clear, translucent, and opaque regions) as a guide for the composition selection. The compositions that provided optically clear regions were selected for melt blending. The ternary (PLA/PCL/CAB) blends were first melt-extruded and then melt-blown to form films and characterized for their tensile properties, tensile fractured-surface morphology, miscibility, crystallinity, molecular weight and chemical structure. The results showed that the tensile elongation at the break (%elongation) of the ternary-blended, melt-blown films (85/5/10, 75/10/15, 60/15/25 of PLA/PCL/CAB) was substantially higher (>350%) than pure PLA (ca. 20%). The range of compositions in which a significant increase in %elongation was observed at 55–85% w/w PLA, 5–20% w/w PCL and 10–25% w/w CAB. Films with high %elongation all showed good interfacial interactions between the dispersed phase (PCL and CAB) and matrix (PLA) in FE-SEM and showed improvements in miscibility (higher intermolecular interaction and mixing) and a decrease in the glass transition temperature, when compared to the low %elongation films. The decrease in Mw and Mn and the formation of the new NMR peaks (1H NMR at 3.68–3.73 ppm and 13C NMR at 58.54 ppm) were observed in only the high %elongation films. These are expected to be in situ compatibilizers that are generated during the melt processing, mostly by chain scission. In addition, mathematical modelling was used to study the optimal ratio and cost-effectiveness of blends with optimised mechanical properties. These ternary-blended, melt-blown films have the potential for use in both packaging and medical devices with excellent mechanical performance as well as inherent economic and environmental capabilities.

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In this work, the mechanical and thermal properties of pineapple leaf fiber (PALF)/poly (lactic acid) (PLA) composites were studied. Pineapple leaf fibers were pretreated with 4 %wt sodium hydroxide solution followed by various silane solutions i.e. γ-(aminopropyl) trimethoxy silane (APS), γ-methacrylate propyl trimethoxy (A174) and bis [3-(triethoxysilyl) propyl] tetrasulfide (Si69). FTIR results show a significant functional groups of C=O and C=C of methacrylic group, NH2group and Si-O which are the characteristic of these silane coupling agents. SEM micrographs of pretreated PALF showed a rough surface while untreated and silane treated PALF revealed less roughness. It was found that the tensile strength at break of PLA is 56 MPa and tensile strength of composites decreased when fiber content increased. The tensile modulus of silane treated PALF composites were higher than PLA, whereas their impact strength were similar to PLA. Si69 treated PALF showed lower impact strength compared to the others silanes treated fiber which indicates more phase separation between fiber and matrix. This is related to high percentage of crystallinity of composite from Si69 treated fiber. It was also found that the addition of PALF did not change the glass transition temperature and melting temperature of PLA while the percentage of crystallinity increases as the fiber content increased. In addition WAXS study of composite from Si69 treated fiber reveals sharp crystalline peaks of PLA while the others silane treatments show amorphous characteristic of PLA.