The goal of this research thrust is to develop bio-based functional polymeric materials from vegetable oils. Vegetable oils are generally considered to be the most important class of renewable resources, because of their ready availability, inherent biodegradability, and numerous applications. In collaboration with the Larock group in the Chemisty Department, a variety of vegetable oil-based polymers have been developed by free radical, cationic, olefin metathesis, and addition polymerization. The polymers obtained display a wide range of thermophysical and mechanical properties from soft and flexible rubbers to hard and rigid plastics, which show promise as alternatives to petroleum-based plastics.
Vegetable oil-based monomers containing reactive functional groups, such as conjugated double bonds, acrylates, and norbornene groups, have been successfully synthesized. These monomers can be polymerized by themselves or copolymerized with petroleum-based monomers using different polymerization methods to afford biorenewable thermosetting materials. Thermal and mechanical properties of these thermosetting materials can be finely tuned by controlling structures of vegetable oil-based monomers or using different kinds of comonomers. Green vegetable oil-based composites can also be obtained by adding fillers, including natural fibers, into these vegetable oil-based thermosets to further reinforce their thermal and mechanical properties.
Vegetable oils can also be converted to polyols, which can further react with diisocyanates to afford polyurethanes (PUs). Novel methods are currently under development to prepare green polyols from vegetable oils in an effective and environmentally-friendly manner. Vegetable oil-based polyols have been used to prepare waterborne polyurethane dispersions (PUDs) without volatile organic compounds (VOCs); these PUDs can find wide applications as coatings, adhesives, and sealants. Interestingly, vegetable oil-based PUDs with ammonium cations in the polymer backbone exhibit strong antimicrobial properties to both gram-positive and gram-negative bacterials, indicating potential applications in food packaging and medical fields.
Chaoqun Zhang, Ruqi Chen, Rui Ding, Tom Garrison, Samy Madbouly, Ying Xia, Zongyu Zhang, Richard Larock, Byron Brehm-Stecher, Michael Kessler