Presidential Green Chemistry Challenge: 2013 Academic Award
Professor Richard P. Wool, University of Delaware
Sustainable Polymers and Composites: Optimal Design
Innovation and Benefits: Professor Richard Wool has created several high-performance materials using biobased feedstocks, including vegetable oils, chicken feathers, and flax. These materials can be manufactured using less water and energy, and producing less hazardous waste compared to petroleum-based processes. Professor Wool's products can be used as adhesives, composites, foams, and even as circuit boards and as a leather substitute.
Summary of Technology: Many advanced composite materials use hazardous chemicals in the adhesive resin and use inorganic fibers for strength. A typical composite like fiberglass might use a styrene-polyester co-polymer, a polyurethane, or an epoxy resin. While the cured resin is unreactive, the uncured form may be quite toxic, posing risk during manufacturing. Furthermore, the resources used to make traditional composites are non-renewable: petroleum, natural gas, and minerals.
Professor Wool has developed several new biobased materials that can be used as substitutes for toxic substances used to make high-performance materials, like adhesives, composites, and foams. The processes to create these biobased materials yield less waste, require less water and energy, and are well-suited to mass production. His materials start with vegetable oils triglycerides and vegetable oil free fatty acids, cellulose and lignin from wood or plant stalks, and fibrous materials such as flax and chicken feathers.
To design these new biobased materials, Professor Wool evaluates the mechanical and thermal properties of the resins, integrates molecular design, and selects products with minimal toxicity. He developed the Twinkling Fractal Theory (TFT) to help predict the functional properties of a material based on its molecular properties, enabling a more focused design approach. He then evaluates the potential toxicity of the materials using the U.S. EPA’s EPI SuiteTM software. Using these design and predictive methods, Professor Wool has synthesized a number of lignin-based replacements for styrene and identified three of these as being less toxic. Other products that Professor Wool has designed include chemically functionalized high oleic soy oil used in pressure sensitive adhesives and elastomers, composite resins, a thermoplastic polyurethane (TPU) substitute, and an isocyanate-free foam from plant oils. The TPU substitute was developed in collaboration with Professor Epps, also of the University of Delaware. In addition to its reduced toxicity, the biobased foam is also compatible with living cells and supports the growth of human tissue. One of Professor Wool’s more recent inventions is a breathable, bio-based “Eco-Leather”, which avoids the traditional leather tanning process and can be entirely vegan. This work was done in collaboration with Professor Huantian Cao of the Fashion and Apparel Department at the University of Delaware.
Since 1992, Professor Wool has been awarded five patents for his safer materials and has applied for three additional patents. As of 2012, Dixie Chemical began producing Professor Wool’s bio-based composite resins for a worldwide market. His discoveries led to the development of soy-based composites used to make boats, tractor panels, and wind turbine parts. He developed the biobased foam replacement for polyurethane in collaboration with Crey Bioresins Inc. This biobased foam is now being considered as a replacement component by several packaging and automotive suppliers. Professor Wool’s start-up company, Eco-Leather Corp., has entered into collaborations with Nike and Puma to use his leather substitute in their products.
- Learn more about green chemistry.
- Learn more about Professor Richard P. Wool and his research.
- Read the press release from the University of Delaware.