Effect of mastic gum integration on improvement of polylactic acid biodegradable films

Abstract

Currently, 90% of all packaging films are composed of non‐renewable, petroleum‐based materials. However, these materials have a significant environmental footprint. Polylactic acid (PLA) is a well‐known biodegradable thermoplastic polymer. However, the use of PLA poses some inherent challenges, like the brittleness of PLA films. For this study, with the objective of overcoming the shortcomings of PLA films, mastic gum (MG), which is an under‐utilized hydrophobic polymer, was incorporated into PLA, and the resultant films were characterized for their chemical (x‐ray diffraction [XRD], Fourier‐transform infrared [FTIR]), thermal (thermogravimetric analysis [TGA], dynamic mechanical analysis [DMA]), optical (optical microscope, color, and opacity), and barrier properties (water vapor permeability [WVP]). MG addition yielded films with much higher opacities and decreased WVPs up to 80%. Optical microscope images revealed the presence of some defects for films with MG concentrations above 1% g/g solvent, which also decreased the film's tear resistance. Glass transition temperature (Tg) values are reduced with MG addition, resulting in less rigid films at room temperature. In the end, MG incorporation yielded more flexible films with much better water barrier properties. In addition, all other properties of the films were drastically modified with MG addition. Hence, MG/PLA is demonstrated to be a promising biopolymer combination for the preparation of biodegradable films as a food packaging material.

Peppermint oil‐infused polylactic acid films: A novel approach for antimicrobial and biodegradable food packaging

“…Localized areas of oil agglomerations and the formation of air‐filled pockets could also play a role in the increase in film thicknesses. An analogous finding was reported in the author's previous study 37 …”

“…This decline suggests a structural break within the film. Previous research has linked similar findings to the formation of pinholes and cracks upon the dispersion of a secondary phase into the polymer matrix of the film 37,58 . These structural weak points act as stress concentrators, initiating tears and leading to premature failure of the film.…”

“…Previous research has linked similar findings to the formation of pinholes and cracks upon the dispersion of a secondary phase into the polymer matrix of the film. 37,58 These structural weak points act as stress concentrators, initiating tears and leading to premature failure of the film. While measures such as degassing might potentially prevent the formation of air-filled holes during film solution homogenization, cracks and other structural imperfections may be a result of the oil dispersion, which might be difficult to prevent.…”

Analytical modeling and experimental estimation of the dynamic mechanical characteristics of green composite: Caesalpinia decapetala seed reinforcement

“…[3][4][5] Many biopolymer materials are cost-effective compared to petroleumbased polymers due to their abundant availability of bioreinforcement and bio-wastage. 6 Biopolymers have extensive potential applications in various sectors such as medicine, textiles, packaging, agriculture, and transport. 7,8 The use of biodegradable composites can reduce the amount of energy wasted during the processing of composites.…”