PLA/functionalized‐gum arabic based bionanocomposite films for high gas barrier applications

Abstract

The present work focuses on the microwave synthesis of lactic acid-grafted-gum arabic (LA-g-GA) by polycondensation reaction and its influence as an additive to improve the gas barrier properties of poly(lactic acid) (PLA) films, prepared by solution casting method. It is observed that during the synthesis of LA-g-GA, hydrophilic gum is converted into hydrophobic due to grafting of in situ grown hydrophobic oligo-(lactic acid). Subsequently, PLA/LA-g-GA bionanocomposite films are fabricated and characterized for structural, thermal, mechanical and gas barrier properties. Path breaking reduction in oxygen permeability (OP) of 10 folds is achieved in case of PLA films containing LA-g-GA as filler. However, water vapor transmission rate (WVTR) is reduced up to 27% after 5 wt % addition of filler. Reduction in OP of this order of magnitude enables the PLA to compete with PET in term of enhancing shelf life and maintaining the food quality.

Facile dispersion of exfoliated graphene/PLA nanocomposites via in situ polycondensation with a melt extrusion process and its rheological studies

“…A sharp diffraction peak is observed for GR at 26.52°, which corresponds to the (002) graphitic carbon structure . The XRD pattern (Figure ) shows a broad band at 2θ ∼ 16.7° for PLA‐M and diluted‐MB composites corresponding to the (110) and (200) planes of PLA . The crystalline regime is reduced because of the fast cooling of the extruded PLA‐M and the composites from molten state to room temperature during fabrication of the composites.…”

“…21,26 The XRD pattern ( Figure 3) shows a broad band at 2u 16.78 for PLA-M and diluted-MB composites corresponding to the (110) and (200) planes of PLA. 16,27 The crystalline regime is reduced because of the fast cooling of the extruded PLA-M and the composites from molten state to room temperature during fabrication of the composites. In case of diluted-MB composites, a broad band around 2u 16.78 indicates a similar crystal structure exists for PLA even after incorporation of graphene.…”

Chemomechanical, morphological, and rheological studies of chitosan‐graft‐lactic acid oligomer reinforced poly(lactic acid) bionanocomposite films

“…In this method, lactic acid was mixed precisely with 30% w/w commercial chitosan in a round‐bottomed flask under environmental conditions; after this, we kept the mixture for 12 h for complete soaking. The soaked mixture was exposed to microwave radiation and convective heating at 110 °C under an inert atmosphere for 30 min at 240 W to perform the condensation polymerization reaction in a microwave . During the reaction, the byproducts, including water and lactide, were removed from the mixture.…”

“…The soaked mixture was exposed to microwave radiation and convective heating at 110 8C under an inert atmosphere for 30 min at 240 W to perform the condensation polymerization reaction in a microwave. 7,16 During the reaction, the byproducts, including water and lactide, were removed from the mixture. After 30 min, the reaction was stopped, and the inert atmosphere was broken by the closure of the gas cylinder valve.…”

Effect of silk nano‐disc dispersion on mechanical, thermal, and barrier properties of poly(lactic acid) based bionanocomposites

“…PLA‐based composites fabricated using biofillers are sparsely represented currently. The influence of different biofillers such as cellulose, starch, cellulose nanocrystals, chitosan, gum, sucrose palmitate, silk on the thermomechanical and permeation properties of PLA have been examined.…”