Work

Pilot-scale supercritical CO₂ impregnation for functionalization of biodegradable PLA/PBAT/TPS films

Year: 2025

Type: article

Abstract: Supercritical fluid impregnation (SFI) is well-documented at lab-scale; however, applications at pilot-scale remain scarce. This study aims to address the gap by investigating the pilot-scale impregnation of biodegradable polylactic acid/poly(butylene adipate-co-terephthalate)/thermoplastic starch (PLA/PBAT/TPS) films using olive leaf extract. The extract of Olea europaea L. leaves was obtained using enhanced solvent extraction. It is a source of pigments and polyphenols, with a concentration of 115 ± 2 mg ml −1 and an EC 50 of 33 ± 3 μg ml −1 . The SFI of PLA/PBAT/TPS films was optimized at lab scale, being 250 bar and 35 °C, the optimal conditions. Under these conditions, SFI was scaled 4-fold, and the effects of extract volume, film surface area, and contact time were evaluated. The quality of the films was assessed based on impregnation homogeneity, extract loading, chemical composition and antioxidant activity against 2,2 ´ -azinobis(3-ethylbenzothiazoline-6-sulfonic) (ABTS). The films impregnated at pilot scale showed optimal results using 30 ml of extract, a 1360 cm 2 film, and 1 h of contact time, achieving an extract loading (1.41 ± 0.08 mg cm −2 ) and antioxidant activity (52 ± 4 %) comparable to those at lab scale. The results confirmed the successful impregnation of polyphenols and suggested interactions between extract compounds and polymer carbonyl groups. Chlorophylls aided the assessment of impregnation homogeneity, a critical factor for product quality, which proved to be consistent throughout the film as the scale was increased. These findings confirm the technical feasibility of SFI at pilot scale and support its potential for sustainable production of bioactive packaging materials. • Pilot scale impregnation enables functionalization of biodegradable PLA/PBAT/TPS films. • Impregnation at pilot scale achieved 1.41 mg cm −2 extract loading in 1 h. • Pigments improved assessment of impregnation homogeneity. • Hydroxytyrosol was the major impregnated polyphenol. • ABTS antioxidant activity reached 52 % under optimal conditions

Source: Journal of CO2 Utilization

DOI: 10.1016/j.jcou.2025.103242

Authors: Noelia D. Machado, Inmaculada Domínguez-Gómez, Cristina Cejudo-Bastante, Casimiro Mantell-Serrano, Lourdes Casas-Cardoso

Institution: Universidad de Cádiz

Language: English

Topic: Nanocomposite Films for Food Packaging

Subfield: Biomaterials

Field: Materials Science

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $3,360