# Evaluation of the Biodegradability Potential of Antibacterial Poly(lactic acid)/Glycero-(9,10-trioxolane)-trialeate Films in Soil

## TL;DR

This study evaluates how well antibacterial PLA films with OTOA biodegrade in soil over 180 days.

## Contribution

The novel contribution is the assessment of biodegradation rates and structural changes in PLA films with varying OTOA concentrations.

## Key findings

- PLA films with 10% and 30% OTOA degrade slower (2 µm·year−1) compared to pure PLA (28 µm·year−1).
- PLA films with 50% OTOA degrade faster (34 µm·year−1) due to structural and crystallinity changes.
- Degradation behavior is influenced by OTOA release rates and material structure during aging in soil.

## Abstract

Glycerol-(9,10-trioxolane) trioleate (OTOA) is a promising material that combines good plasticizing properties for PLA with profound antimicrobial activity, which makes it suitable for application in state-of-the-art biomedical and packaging materials with added functionality. In this study, the biodegradation kinetics of PLA + OTOA mixed films under soil conditions was assessed over 180 days. Structural and morphological changes that occurred on the surface and in the volume of the films during degradation were scrutinized using DSC, X-ray diffraction, IR, and UV spectroscopy. Morphological changes were assessed using optical and confocal microscopes. The different behavior of the PLA + OTOA blend films during decomposition in soil is explained by their structure and the rate of release of antibacterial OTOA from the PLA matrix. The decomposition rate constants were determined for all films, where kd for PLA samples is 28 µm·year−1, for samples containing 10% and 30% OTOA kd is 2 µm·year−1, and for PLA + 50% OTOA samples kd = 34 µm·year−1. This is explained by changes in the structure and degree of crystallinity of materials during the process of aging in the soil. These results clarify the biodegradation processes of biomaterials containing antibacterial agents in their structure.