(187s) Biodegradation Study of Polylactic Acid (PLA) Based Non-Woven Fabrics Under Controlled Condition

Polypropylene (PP) based melt-blown (MB) and spun-bond (SB) nonwovens are commonly used for developing personal protective equipment (PPE) and high-performance filter media. After their use, they often end up in landfills and on the ocean surface due to ineffective collection and recycling programs, which consequently generate a high volume of plastic waste. Polylactic acid (PLA), a linear aliphatic bio-based (corn, sugar cane, etc.) thermoplastic polyester, has been used to replace PP-based nonwoven. However, evaluating the degradation of the PLA nonwoven materials in industrial composting conditions is crucial for assessing their decomposition mechanism and rates for their potential application in personal protective equipment. This understanding can provide valuable insights into the environmental impact and end-of-life of final products. Therefore, the objective of this study was to investigate the biodegradation (Respirometric study through CO₂ evolution) behavior of PLA-based nonwoven fabrics under controlled conditions.

A Respirometric study (cumulative CO₂ evolution in mg) is in progress to investigate the degradation behavior of PLA-MB, PLA-SB, and PLA-PHA blended MB fabric in controlled composting conditions (ASTM D5338, 58°C, moisture content: 50-55%) using Columbus Instruments' Micro-Oxymax system, USA. Solid waste (C/N ratio:12.2) from the University of Georgia (UGA) yard compost facility was used as inoculum, and the sample-to-compost ratio was 1:15 (oven-dry weight of compost). After 16 weeks of study, almost 80% biodegradation was found for PLA-MB fabric.

This study also investigates the biodegradation kinetics to explore how the material properties (composition, surface area) and environmental conditions (temperature variations) influence biodegradation rates of the nonwoven webs. Furthermore, time-dependent mass loss under controlled temperature will be quantified to model degradation kinetics and assess the interaction between intrinsic polymer characteristics and external factors. The findings of the study will be presented.