When life gives you lemons… make a BPA replacement for polycarbonates

Chemists at ICREA (The Catalan Institute for Research and Advanced Studies, based in Barcelona) have produced an eco-friendly Method to make a BPA-free polycarbonate from limonene and carbon dioxide.

A team of scientists led by Arjan Kleij, ICIQ group leader and ICREA professor, has developed a method to use limonene to replace bisphenol-A, a constituent part of polycarbonate that is a potential carcinogen if in extremely high volumes, though classified as a safe chemical by American and European agencies.

Arjan Kleij, project leader, said “BPA is safe, but still causes concerns and is produced from petroleum feedstock. Our approach replaces it with limonene, which can be isolated from lemons and oranges, giving us a much greener, more sustainable alternative. Because fully replacing BPA for limonene can be complicated for most industries at this moment BPA can increasingly take over. We can start adding small quantities of limonene, then progressively substituting BPA. Step by step, the adaptation process could lead to new limonene derived biomaterials with similar, or even enhanced and novel properties.”

The researchers also managed to improve the polymer’s thermal properties, as it proved the highest glass transition temperature ever reported for a polycarbonate.

Kleij said: “Bio-plastics have worse thermal properties than classic polymers. We were first sceptical about these findings, but we were able to reproduce this feature.”

The researchers are currently negotiating with plastic producers to further advance the industrial manufacture of limonene-derived biomaterials.