The doctoral thesis of Leticia Peña focuses in the development of synthetic methods towards bio-based polymers. Her first project involved the optimization of polycarbonate formation from CO₂ and epoxides. CO₂ is considered a waste material so its an ideal synthon for the manufacture of biorenewable polymers. Furthermore, the coupling of CO₂ was optimized with limonene oxide, a terpene based material, yielding a completely biobased material with good thermal properties.

She later moved on to polyesther synthesis by the reaction of anhydrides and epoxides. She studied different catalysts and condition, which were active in these reactions, and investigated the potential of making this kind of polymers from biobased monomers. To finish up she worked on the transformation of fatty acids into useful starting materials for poly hidroxy urethanes.