Abstract The work describes compositions of D-polylactic acid and corn starch as a fine filler, having both the ability to biodegrade and an electric field (corona electrets). The work explores the composition of D‑polylactic acid (PLA) combined with corn starch as a fine filler, both exhibiting biodegradability and acting as a corona electret under an electric field. The infrared (IR) spectrum of PLA reveals characteristic bands that reflect its chemical structure and functional groups: the bands in the 3200–3600 cm−1 range correspond to O–H stretching, those in the 2950–2870 cm−1 range correspond to C–H asymmetric and symmetric stretching, and the pronounced bands in the 1750–1800 cm−1 range relate to C=O stretching of carbonyl groups, while the bands in the 1300–1450 cm−1 range correspond to CO–C and C–C stretching. Bands indicative of ether group stretching are found in the 1000–1300 cm−1 range. Similar bands are observed in the IR spectrum of starch, as it contains analogous functional groups. However, starch exhibits stronger absorption bands around 3300–3500 cm−1, which are mirrored in the spectrum of the PLA–starch composites; specifically, higher starch content correlates with increased intensity in this region. Moreover, interactions between PLA and starch alter the IR spectrum of their compositions. Experimental data reveal that the surface potential of polymer matrices composed of 2–6% starch exceeds that of pure PLA. This enhancement in the accumulation and retention of electric charge carriers in the polymers is attributed to the formation of new trapping sites within the filler structure and at the polymer matrix interface. The high polarizability of starch contributes to local field effects, further facilitating charge retention, while its hygroscopic nature enables moisture retention, significantly influencing the electret characteristics of the polymer. The patterns observed in the surface potential of PLA and its starch composites over time align with typical behaviors seen in various polymer-based corona electrets. Two distinct phases are identified: an initial sharp decline in surface potential values followed by stabilization. These dynamics are controlled by the trapping of charge carriers in shallow, quickly depleting energy traps versus deeper traps that determine the electret’s longevity. The findings conclude that including 2–6% starch into polylactic acid enhances its electret properties, suggesting the potential for developing active packaging solutions that extend the shelf life of food products.

Biodegradable PLA–Starch Composite for Active Packaging

期刊论文
发表日期：

2025年8月1日

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I. A. Zagidullina,
A. A. Guzhova,
A. I. Khasanov

摘要

Abstract

The work describes compositions of D-polylactic acid and corn starch as a fine filler, having both the ability to biodegrade and an electric field (corona electrets). The work explores the composition of D‑polylactic acid (PLA) combined with corn starch as a fine filler, both exhibiting biodegradability and acting as a corona electret under an electric field. The infrared (IR) spectrum of PLA reveals characteristic bands that reflect its chemical structure and functional groups: the bands in the 3200–3600 cm⁻¹ range correspond to O–H stretching, those in the 2950–2870 cm⁻¹ range correspond to C–H asymmetric and symmetric stretching, and the pronounced bands in the 1750–1800 cm⁻¹ range relate to C=O stretching of carbonyl groups, while the bands in the 1300–1450 cm⁻¹ range correspond to CO–C and C–C stretching. Bands indicative of ether group stretching are found in the 1000–1300 cm⁻¹ range. Similar bands are observed in the IR spectrum of starch, as it contains analogous functional groups. However, starch exhibits stronger absorption bands around 3300–3500 cm⁻¹, which are mirrored in the spectrum of the PLA–starch composites; specifically, higher starch content correlates with increased intensity in this region. Moreover, interactions between PLA and starch alter the IR spectrum of their compositions. Experimental data reveal that the surface potential of polymer matrices composed of 2–6% starch exceeds that of pure PLA. This enhancement in the accumulation and retention of electric charge carriers in the polymers is attributed to the formation of new trapping sites within the filler structure and at the polymer matrix interface. The high polarizability of starch contributes to local field effects, further facilitating charge retention, while its hygroscopic nature enables moisture retention, significantly influencing the electret characteristics of the polymer. The patterns observed in the surface potential of PLA and its starch composites over time align with typical behaviors seen in various polymer-based corona electrets. Two distinct phases are identified: an initial sharp decline in surface potential values followed by stabilization. These dynamics are controlled by the trapping of charge carriers in shallow, quickly depleting energy traps versus deeper traps that determine the electret’s longevity. The findings conclude that including 2–6% starch into polylactic acid enhances its electret properties, suggesting the potential for developing active packaging solutions that extend the shelf life of food products.