Innovation in Textile Finishes: Safer, Water-Repellent Fabrics
In the quest for safer, more sustainable textile finishes, scientists are turning to epoxidised cottonseed oil (ECSO) as a potential alternative to traditional chemical resins. The shift comes after concerns over formaldehyde-based finishes and PFAS, compounds long used to impart wrinkle resistance and water repellency but linked to health and environmental risks. A group led by fourth-year PhD student Taylor Kanipe and plant-based resources expert Richard Venditti at North Carolina State University (NCSU) is investigating ECSO’s ability to bond with cotton fibers while delivering the kind of performance consumers expect from modern fabrics.
From Formaldehyde to Epoxidised Oils: A Safer Path Forward
Conventional wrinkle-resistant finishes rely on formaldehyde-based resins, which adhere to the cellulose fibers in cotton. While effective, formaldehyde poses toxicity concerns, especially with prolonged exposure. In parallel, water-repellent finishes have often used PFAS, a class of substances associated with persistence in the environment and adverse health effects. The researchers’ focus on ECSO offers a potentially safer route by leveraging chemistry that forms a hydrophobic, durable layer without the reliance on hazardous solvents or persistent compounds.
How ECSO Works on Cotton Fibers
When applied, epoxidised cottonseed oil molecules bond strongly with each other to form a hydrophobic polymer. This polymer not only repels water but also creates molecular bridges between the cotton cellulose fibers, enhancing wrinkle resistance. The result is a fabric surface that stands up to moisture and wear while potentially reducing environmental and health risks tied to traditional finishes.
Measuring Performance: Hydrophobicity and Beyond
To quantify water-repellent performance, the team used a high-speed camera to observe water droplets on treated versus untreated fabrics. The crucial metric is the contact angle—the angle at which a water droplet meets the fabric surface. Materials with a contact angle above 90° are considered hydrophobic. In tests, untreated cotton absorbed water readily, showing no measurable contact angle. By contrast, ECSO-treated fabric achieved a contact angle of 125°, a clear indication of superior water-repellent capability as reported by Chemistry World.
Next Steps: Emulsion-Based Finishes and Sustainability
A key goal for the NC State team is to refine ECSO finishing into an oil-in-water emulsion. This approach would reduce or eliminate the need for solvents such as hexanes, aligning with sustainability aims and improving process safety. The emulsion route could simplify application while maintaining or enhancing performance, making ECSO-finishes more viable for scale-up.
Scale-Up and Real-World Testing
The research has progressed within the facilities of Cotton Incorporated, a Cary, North Carolina-based nonprofit that supports cotton innovation. Cotton Incorporated’s lab-scale and pilot-scale equipment enables investigators to explore how ECSO-based formulations perform under real-world production conditions. The researchers are not just testing water repellency; they also plan to evaluate durability, tear strength, and overall fabric longevity, crucial factors for consumer acceptance and commercial viability.
Looking Ahead: What ECSO Could Mean for the Textile Industry
Should ECSO prove effective at scale, it could mark a meaningful shift away from hazardous finishes toward more sustainable, plant-derived alternatives. The potential benefits extend beyond consumer safety: reduced reliance on volatile solvents, lower environmental footprints, and alignment with growing regulatory and consumer pressures for greener textiles. As the NC State team continues to optimize formulations and processing methods, the industry watches for data on long-term performance and cost-efficiency alongside environmental impact.
In the near term, the researchers will expand their testing suite to include additional performance metrics and explore how ECSO interacts with different cotton grades and textile constructions. The work signals a broader trend in textile science: reimagining common finishes through bio-based chemistries that deliver durability without compromising human health or the planet.
