Hybrid Biocomposites Based on Poly(Lactic Acid) and Silica Aerogel for Food Packaging Applications

Abstract

Bionanocomposites based on poly (lactic acid) (PLA) and silica aerogel (SiA) were developed by means of melt extrusion process. PLA-SiA composite films were plasticized with 15 wt.% of acetyl (tributyl citrate) (ATBC) to facilitate the PLA processability as well as to attain flexible polymeric formulations for films for food packaging purposes. Meanwhile, SiA was added in four different proportions (0.5, 1, 3 and 5 wt.%) to evaluate the ability of SiA to improve the thermal, mechanical, and barrier performance of the bionanocomposites. The mechanical performance, thermal stability as well as the barrier properties against different gases (carbon dioxide, nitrogen, and oxygen) of the bionanocomposites were evaluated. It was observed that the addition of 3 wt.% of SiA to the plasticized PLA-ATBC matrix showed simultaneously an improvement on the thermal stability as well as the mechanical and barrier performance of films. Finally, PLA-SiA film formulations were disintegrated in compost at the lab-scale level. The combination of ATBC and SiA sped up the disintegration of PLA matrix. Thus, the bionanocomposites produced here show great potential as sustainable polymeric formulations with interest in the food packaging sector.

Developments of biobased plasticizers for compostable polymers in the green packaging applications: A review

“…The plasticization effect of CAPs on PLA systems including PLA/soy protein concentrate (SPC)/poly (butylene adipate‐co‐terephthalate) (PBAT) composites, 74 PLA/PBAT blend, 91 PHB/PLA blends, 69,92 PLA and silica aerogel, 93 natural rubber/PLA, 94 and PLA/PCL 75 were also reported. Most of these studies described the good efficiency of these plasticizers in PLA blend.…”

Improvement of PBAT Processability and Mechanical Performance by Blending with Pine Resin Derivatives for Injection Moulding Rigid Packaging with Enhanced Hydrophobicity

“…Aliphatic biopolyesters, such as PLA and PHB, have been, to date, the most promising biodegradable polymers for biodegradable or compostable food packaging products [7]. However, aliphatic biopolyesters present some drawbacks for food packaging applications with respect to their petrochemical counterparts such as sensitiveness to hydrolytic degradation, which is highly influenced by ambient moisture and temperature, leading to low thermal stability [7,15,16]. Additionally, for food packaging purposes, their poor barrier properties and inherent unfavourable physical and mechanical properties, such as their limited stretchability, have limited their commercial utility [7,17].…”

Influence of plasticizers on the compostability of polylactic acid

“…have recently developed PLA plasticized with 15 wt.% of ATBC and further loaded with silica aerogel and founded that both additives provided opposites effects. While ATBC leads to a expected increase in the disintegration rate, the silica aerogel promoted a higher degree of crystallinity, which was enhanced at the temperature of the composting test, which entails a decrease in the disintegration rate (Aragón-Gutierrez et al, 2020).…”

“…While in the case of injecteinjection-molded pieces (with thickness of 4 mm) the required time is between 6 and 8 weeks) (Quiles-Carrillo, Montanes, Lagaron, Balart, & Torres-Giner, 2018a). For instance, typical plasticizers for PLA are poly(ethylene glycol) (PEG) (Arrieta, J. López, et al, 2014a) and acetyl-tri-butyl citrate (ATBC) (Aragón-Gutierrez, Arrieta, López-González, Fernández-García, & López, 2020;Arrieta, Fortunati, Dominici, López, & Kenny, 2015;Arrieta, López, et al, 2014a;Arrieta, Peponi, López, & Fernández-García, 2018), and both are able to increase the PLA disintegration in compost (see Figure 6).…”