Biobased BPA-Free Epoxy Coatings for Food and Beverage Applications

In this Phase 1 SBIR proposal, Vuronyx Technologies will develop biobased isosorbide epoxy precursors as replacement to Bisphenol-A epoxy precursors used currently in "can coatings" for food and beverages.Canning of foods and beverages in tin-plated steel or aluminum is extensively used for food preservation and storage because of low material and productions costs and durability of the containers. The metallic cans are typically coated with an epoxyresin as a protective layer that separates foods and drinks from the metal containers. The epoxy protective coating is required to prevent metal corrosion and/or penetration of bacteria into cans that could reduce their freshness, taste, odor, and nutritional properties.Epoxy precursors are typically based on Bisphenol-A (BPA), which is classified as an endocrine-disrupting chemical (EDC) due to its ability to mimic estrogen binding. Health hazards of EDCs are well-established - including cancer, brain and behavioral changes in fetuses, and female reproductive issues. Food and beverage companies are not only being challenged by regulatory agencies to phase out their use of BPA, but are also being pressured by increasingly health conscious customers.Various bio-based precursors have been investigated to prepare BPA replacement, such as vegetable oil, rosin, lignin, and itaconic acid, but they do not possess the desirable properties of BPA based epoxies, namely high Tg, low water uptake, and desirable mechanical properties.Our aproach is based on replacing Bisphenol bis(glycidyl ether) with isosorbide based epoxy. Isosorbideis a cheap biobased precursor material made by dehydrating sorbitol which is a polyhydric alcohol derived by reduction of glucose. Roquette, a French chemical company, recently launched world's largest isosorbide production facility of 20,000 tons/year, and have plans for further capacity expansion.The rigid structures and special molecular geometry make isosorbide a good candidate to replace BPA without the endocrine disrupting effect. Isosorbide can serve as renewable building blocks for many applications including thermoplastics, thermosets and specialty chemicals.Isosorbideand its isomers can be attached to glycidyl ether to make crosslinkableepoxy resin monomers with properties similar to BPA glycidyl ether.