Edwin L. Aguirre
A team of researchers at UMass Lowell led by plastics engineering Assoc. Prof. Daniel Schmidt
has identified and tested a potential chemical substitute for bisphenol A, or BPA, in the epoxy resin used to line the metal cans of food, beverages and infant formulas.
“For a long time now, there have been various alternatives to BPA-based can coatings but all of them have been either lower-performing, less versatile, more expensive or some combination thereof,” says Schmidt. “In this case, we feel like we finally have something that has a chance of being the drop-in replacement that manufacturers, consumers and regulators have been searching for.”
have raised concern about the health risks of long-term, low-dose exposure to BPA in humans. BPA is known to mimic the hormone estrogen, and this can pose possible adverse effects to human reproduction and development.
Preliminary test results of the team's new compound — a monomer called bis(epoxide) of 2,2,4,4-tetramethyl-1,3-cyclobutanediol — show that it holds promise for use in high-performance BPA-free epoxy resins.
“We have to be sure, of course,” says Schmidt. “Things are not totally solved yet, but so far, so good. The results have been very promising so this has been pretty exciting.”
Other members of the team include Robert Romano, who graduated in 2012 with a master’s degree in plastics engineering, and Smruti Patil, who is currently Schmidt’s most senior doctoral student from the Biomedical Engineering and Biotechnology program.
Is BPA Substitute Safe?
Schmidt says there a few things that the new material has going for it.
“First, as far as we can tell, the acute toxicity of the monomer used to make our epoxy is quite low,” he notes. “Second, in contrast with BPA, its structure bears no resemblance to estrogen or any other human hormone. Third, published tests of the endocrine-disrupting potential of this monomer — that is, its ability to mimic hormone — have shown effectively no activity in comparison with BPA. All other things being equal, then, we believe it is fair to say that replacing BPA with the monomer we’ve chosen will produce an economical, high-performance epoxy resin that generates less concern than any bisphenol-based epoxy.”
The team’s work was initially funded by the Massachusetts Toxics Use Reduction Institute (TURI
). The researchers used the seed grant to generate enough results to win additional funding through the UMass Commercial Ventures and Intellectual Property (CVIP) Technology Development Fund.
More R&D Needed
Schmidt and his team are currently working with an epoxy manufacturer to scale up their synthesis to produce a few kilograms of material so they can sample it to various companies for evaluation.
“We will also be taking the simplest, lowest molecular weight form of the epoxy — that is, what we will make and sample first — and ‘upgrading’ the material to a higher molecular weight to create a so-called ‘solid epoxy,’ which is what is needed for can coatings,” says Schmidt. “The hope is that some, if not all, of our industrial contacts find our materials useful and will be interested in pursuing further development with us.”