Session: Polymer Division Student Poster Session: Celebrating the Diversity of Macromolecules:

Polyurethanes are oil-based synthetic polymers frequently used in the manufacture of various materials such as synthetic fibres or hard plastics. Traditionally, polyurethanes are synthesized by reacting polyols with isocyanates, both derived from crude oil, to form the urethane linkage. Along with depleting our natural resources, this process can be toxic to both humans and the environment. Phosgene, a toxic gas, is used to make the required isocyanates and can cause negative health effects. Isocyanates themselves are also considered toxic, and therefore the production of polyurethanes requires high levels of safety measures. Even with low levels of biodegradability, small amounts of polymer degradation can lead to the formation of carcinogenic aromatic amines released into the environment. These safety, toxicity, and biodegradability issues have led to the need for safer and greener alternatives to polymer synthesis.
In this presentation, we will discuss greener methods to produce polyurethane materials. Previous synthetic routes have avoided the use of isocyanates by incorporating plant-based oils into the process. However, using these oils for polymer synthesis can compete with food production. Our research incorporates fish oil derived from aquaculture waste, a biomass-derived material that does not compete for land space. It was found that capelin-herring fish oil or fish oil extracted from salmon offal can be epoxidized and reacted with CO₂ to form carbonated fish oil, which can then form a non-isocyanate polyurethane material (NIPU) from a reaction with a diamine. Biodegradability studies were performed on the resulting films under enzymatic conditions to determine the level of degradation the polymer would undergo, and Scanning Electron Micrographs suggest high levels of degradation. Further improvement of the synthetic process was then attempted by screening the reactivity of biocompatible amino acids in the crosslinking process. L-histidine, L-glutamine, and L-asparagine were chosen and tested for a reaction with the carbonated fish oil via Differential Scanning Calorimetry. Results show an exothermic reaction between the carbonated fish oil and the L-histidine, showing the potential of a crosslinking reaction to form a NIPU.

Mikhailey D Wheeler

Memorial University of Newfoundland

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