Conference Speakers

Maitry Bhattacharjee

Ph.D. Student & Graduate Research Assistant, University of Georgia

Degradation of Polylactic acid (PLA) based Nonwoven Fabrics Under Controlled Conditions (soil burial and respirometric studies)

"Polypropylene (PP) based non-woven fabrics from melt-blown and spun-bond processes are commonly used in personal protective equipment (PPE), and high-performance filtration applications. After use, they often end up in landfills and oceans due to ineffective collection and recycling programs. Polylactic acid (PLA), a linear aliphatic bio-based (corn, sugar cane, etc.) thermoplastic polyester has been used to replace PP for these applications. Understanding the degradation of PLA nonwoven fabrics under soil or compost conditions is critical to evaluating their potential for disposable PPE. Therefore, this study aimed to investigate the degradation behavior of PLA non-woven fabrics in soil and during composting under controlled conditions.

The soil burial experiments were carried out in the environmental growth chamber maintained at 25°C and 50-60% RH with artificial light sources for six months. Small plastic containers (15×30×10cm) filled with a mixture of local soil (80% wt.) and compost (20% wt.) were used. Four non-woven fabric samples (two PLA melt blown, one PLA spun bond, and one PP melt blown) cut to a size 10 cm wide and 20 cm long were used. Each fabric sample was buried at a 5cm depth with 18 replications (6 months×3). After months 1, 2, 3, 4, and 6, each fabric samples were removed, cleaned, and observed for visual degradation. Moreover, the change in fabric structure and properties including dimensional changes, and physical, thermal, and surface properties were determined by FT-IR, DSC-TGA, and SEM. After six months, PLA melt-blown fabrics showed signs of degradation while PP & PLA spun bond fabrics exhibited no significant property changes. Furthermore, a four-month respirometer study was conducted to investigate the degradation behavior of PLA nonwoven and PLA-PHA blended films in standard composting conditions (58°C, moisture content: 50-55%). The cumulative CO2 evolution and the biodegradation rate of the PLA fabrics were quantified and reported."