Research Assistant Professor Umesh Marathe with UT-ORII’s Circular Bioeconomy Convergent Research Initiative was a UT Research Foundation featured innovator for his new open disclosure.
What if the plastic cap on your favorite beverage could simply biodegrade after use — without any change to how it’s made? That’s exactly what Marathe’s team is working toward. They’ve developed a next-generation biodegradable composite based on polybutylene succinate (PBS) that achieves a density lighter than water, making it the first truly viable drop-in replacement for conventional plastics like PE and PP in bottle caps, lids, and everyday packaging components. Lower density is engineered to facilitate easier recovery and recycling. The secret lies in a carefully engineered composite of tailored additives and lightweight fillers that simultaneously deliver strength, UV resistance, CO2 barrier protection, and the moldability manufacturers already rely on, making it a competitor for the existing choice of material.
What makes this work even more exciting is the depth of expertise and resources that brought it to life. This invention was developed in-house, leveraging the combined research capabilities of ORNL and UT through UT-ORII, including melt mixing, molding and characterization facilities. Beyond bottle caps, this technology could reshape how we think about materials across food and beverage, pharmaceuticals, agriculture, and consumer goods industries. The team is not only creating a better composite but also demonstrating that performance and environmental responsibility do not have to be a trade-off. This also aligns well with UT-ORII’s Circular Bioeconomy CRI goals for packaging applications. Graduate student Joslin Joshy and undergraduate student Matthew Vaught are assisting Marathe with the research.
