Advanced Biobased Polymers from Limonene Oxide

The development of polymer materials derived from renewable resources for replacement of petroleum based ones is gaining growing interest both in industry and in the scientific research community1,2. Typically, 80% or more of the manufacturing costs arise from the monomers, which are derived from petroleum. The depletion of fossil resources prompts to find alternative carbon supply, such as CO2, a waste by-product emitted by combustion of fossil fuels and coal fired power stations, and non-food based biomass. Terpenes represent a plentiful and inexpensive class of non-polar substrates with enormous potential for the synthesis of bio-based polymeric materials and limonene is the most common terpene. The (R)-enantiomer constitutes 90-96% of citrus peel oil lemons, oranges and grapefruits 2,3. Limonene oils, are industrially obtained as a by-product of citric fruit juice processing and are then oxidized to form mono- as well as difunctional epoxides. (R)-limonene oxide (LOx) represents an excellent choice as a bio-renewable epoxide monomer for copolymerization with CO2, thanks to several features such as low cost, abundance, and structural similarity to cyclohexene oxide (CHO). Here we present the synthesis of alternating polyesters through reaction of succinic-, phthalic-, maleic- and norbornyl- anhydrides with LOx and CHO by using salen metal complexes (Metal = Cr, Al, Mn) with different cocatalysts, under various reaction conditions by Ring Opening COpolymerization (ROCOP) as well as the synthesis of polycarbonates based on LOx and CO2. The resulting polyesters and polycarbonates have been fully characterized by thermal (DSC), molecular (SEC) and microstructural (1H and 13C NMR) analysis. References 1.E. Hosseini Nejad, A. Paonisari, C. G. W. van Melis, C. E. Koning, R. Duchateau, Macromolecules, 2013, 46, 631. 2.E. Hosseini Nejad, C. G. W. van Melis, T. J. Vermeer, C. E. Koning, R. Duchateau, Macromolecules, 2012, 44, 1770. 3.R. T. Mathers, J. Polym. Sci., Part A: Polym. Chem., 2012, 50, 1. 4.R. T. Mathers, S. P. Lewis, Green Polym. Methods, 2011, 91. Acknowledgments Project n. CARIPLO Foundation "Advanced POLymers from Limonene Oxide as sustainable feedstock-APOLLO" 2017-2019