Biopolymers & Biocomposites Workshop - August 14, 2012

Effect of Unsaturation on Vegetable Oil-Based Polyurethane Coatings

Thomas F. Garrison, Richard C. Larock, and Michael R. Kessler
Iowa State University

A variety of vegetable oil-based, waterborne polyurethane dispersions (PUDs) have been successfully synthesized from different vegetable oil polyols with hydroxyl functionality approximately constant at 2.7. The vegetable oil polyols, which were prepared using vegetable oils with different fatty acid compositions (peanut, corn, soybean, and linseed oil), ranged in residual degree of unsaturation from 0.4 to 3.5 carbon-carbon double bonds per triglyceride molecule. The effects of residual unsaturation on thermal and mechanical properties of the resulting polyurethane films have been investigated with dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. Higher residual unsaturation results in polyurethane films with increases in tensile strength, Young’s modulus, and toughness. This work isolates the effect of unsaturation on vegetable oil based polyurethane films which had previously been neglected in other studies.