Green nanocomposites of poly(lactic acid)/banana fibre/nanoclay were successfully prepared using melt-blending technique followed by injection moulding. Untreated and chemically modified banana fibres and organically modified nanoclay (Cloisite 30B) were used as reinforcing agent within the poly(lactic acid) matrix. The banana fibres were subjected to various chemical modifications such as mercerization, silane treatment, sodium lauryl sulphate treatment, permanganate treatment and combination of mercerization and silane treatment. The biocomposites and bionanocomposites were subjected to characterization tests i.e. mechanical properties, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, heat deflection temperature (HDT), morphological properties using scanning electron microscopy and transmission electron microscope and water-absorption studies to evaluate the effect of chemical modification of banana fibre and incorporation of nanoclay. Silane-treated fibre-reinforced poly(lactic acid) composites and its bionanocomposites displayed optimum tensile and flexural properties than that of virgin poly(lactic acid) resin, whereas the impact strength of composites showed a reverse order due to the brittle nature of matrix. Dynamic mechanical analysis result shows that the storage modulus of the bionanocomposites increases with respect to the virgin poly(lactic acid) and biocomposites. Differential scanning calorimetry results revealed that the glass transition was not significantly changed; however, the incorporation of both silane-treated fibre and C30B nanoclay enhanced the nucleation of poly(lactic acid) crystallites as well as increased the melting temperatures. The results of thermogravimetric analysis depicted that fibre modification and incorporation of nanoclay can improve the degradation temperature of the composites. Scanning electron micrographs demonstrated improper dispersion of untreated fibres and proper dispersion of treated fibres within the poly(lactic acid) matrix, thereby revealing the interfacial adhesion between the fibres and matrix. Additionally, the composites were subjected to water-absorption studies, which revealed that bionanocomposites exhibited better water resistance than biocomposites.

The current research focuses on the degradation kinetics of fully bio-based hybrid bionanocomposites of poly (lactic acid) (PLA), utilizing banana fiber and nanoclay as reinforcing fillers. The bionanocomposites were prepared using melt blending technique followed by injection molding. The reinforcing effect of silane treated banana fiber (SiB) and Closite 30B (C30B) nanoclay on the thermal stability and fire retardancy of PLA has been studied. Isoconversional kinetic analysis using Friedman and Flynn-Wall-Ozawa method as well as analysis based on parameters at the maximum degradation rate (Kissinger method) were employed to understand the thermal degradation kinetics in the bionanocomposites. The results from thermogravimetric analysis (TGA) revealed that bionanocomposites have improved thermal stability. The UL-94 horizontal burning test and cone calorimetry have been used to screen the flammability performance of PLA and its biocomposites as well as bionanocomposites. The results revealed that the incorporation of SiB and C30B nanoclay improved fire retardancy. Further, the structural characterization has been carried out using FTIR. POLYM. COMPOS., 00:000-000,

The main aim of this study was to synthesis of poly (lactic acid) (PLA)-graft-glycidyl methacrylate (GMA) as well as its influence on the properties of PLA/banana fiber biocomposites. PLA-graft-GMA graft copolymer (GC) was synthesized by melt blending PLA with GMA using benzoyl peroxide and dicumyl peroxide as initiators. Graft copolymerization was confirmed by FTIR and 1 H-NMR spectroscopic studies. PLA/silane treated banana fiber (SiB) biocomposites with various GC concentrations were prepared by melt blending followed by injection molding techniques. The influence of GC content on the mechanical, thermal and moisture resistance properties of the composite was investigated. The addition of 15 wt% GC content in the biocomposite provided optimum tensile and flexural strength, which is attributed to the greater compatibility between fiber and PLA matrix. The thermal properties of biocomposites have been evaluated using thermogravimetric analysis which provided evidence of improved interfacial adhesion between SiB and PLA by the addition of GC. Additionally, GC enhanced the moisture absorption resistance of biocomposites. These results indicated that GC is indeed a good candidate as a compatibilizing agent to improve the compatibility in PLA/fiber biocomposites.

Biocomposites of poly(lactic acid) (PLA) reinforced with silane treated banana fiber (SiB) were prepared using melt blending technique. To improve the compatibility, a secondary reinforcing filler (Cloisite 30B (C30B) nanoclay) as well as graft copolymer, poly(lactic acid)‐graft‐glycidyl methacrylate (PLA‐g‐GMA) as a compatibilizing agent were incorporated in to PLA/SiB biocomposites. PLA‐g‐GMA was synthesized by free radical copolymerization of different concentration (10, 15, 20, and 25 wt%) of glycidyl methacrylate (GMA) with PLA and was confirmed by Fourier transform infrared spectroscopy spectroscopy and titration method. The influence of C30B nanoclay as well as PLA‐g‐GMA on the thermal and flammability characteristics of PLA/SiB have been studied. The thermal characteristics of composites have been evaluated by thermogravimetric analysis (TGA). The activation energy of the composites has been estimated using Friedman, Kissinger, and Flynn–Wall–Ozawa (FWO) methods by employing TGA. The obtained activation energy revealed that PLA‐g‐GMA compatibilized bionanocomposites had better thermal stability. Furthermore, flammability properties were obtained from UL‐94 horizontal burning test and cone calorimetry showed enhancement of flame retardant properties after addition of C30B and PLA‐g‐GMA. J. VINYL ADDIT. TECHNOL., 23:E81–E91, 2017. © 2016 Society of Plastics Engineers

This work reports on the influence of moisture absorption and accelerated weathering on the properties of graft copolymer compatibilized bionanocomposites of poly(lactic acid) (PLA). Moisture absorption tests were conducted for 30 days by immersing the samples in a distilled water bath at room temperature, and the amount of moisture absorbed in each time interval was measured. The rate of moisture uptake decreased by incorporation of C30B nanoclay and graft copolymer into fiber-reinforced PLA composites. Changes in the mechanical properties of composites in each time interval of moisture absorption were investigated using tensile and impact tests. Exposure to moisture caused significant drops in the mechanical properties. The morphological characterization of biocomposites during the aforementioned tests has been made using SEM, while bionanocomposites were analyzed by TEM. Further, this paper also reported the effect of accelerated weathering on the mechanical properties and the results are confirmed through SEM analysis. Biodegradation behaviors of PLA biocomposites and bionanocomposites have also been studied.