The uncertain cost of petroleum and its expected depletion in the near future prompted the scientific community to search for new sources of carbon just inexpensive, abundant and easily exploitable. Combining the use of renewable resources such as vegetable oils and carbon dioxide as a carbon source for the development of a sustainable chemistry is very promising. Thus, this research project fits within the framework of the chemical fixation of CO2 and the utilization of vegetable oils as a substitute for basic petroleum derivatives for the production of new monomers and new bio-based organic polymers. As a first step, the catalytic synthesis of cyclic carbonate monomers from CO2 and vegetable based epoxidized oils (and/or the corresponding fatty esters) will be considered. The synthesis of non-isocyanates polyurethanes (NIPUS) will then be performed by reacting in bulk these new monomers with diamines under mild heating.
The objective of the thesis work is twofold.
First of all, we will investigate various catalytic platforms enabling the cycloaddition of CO2 on vegetable based epoxidized oils in the most efficient way under mild conditions. For such task, in situ kinetic follow-up of this reaction will be performed by FT-IR or Raman spectroscopy in order to identify the best catalytic systems and to evaluate the influence of various parameters (pressure, temperature catalyst concentration, nature of epoxidized oil) on the yields and the reaction kinetics. The most efficient catalytic systems will then be investigated by molecular modeling to identify the key structural parameters of the catalyst that govern its efficiency.
In a second step, the synthesis of NIPUS will be performed by condensation in bulk between the carbonated vegetable oil (or fatty esters) and a given diamine by heating (60-80°C) under atmospheric pressure with or without catalyst. A series of diamines (aliphatic, aromatic) will be considered to optimize yields of polymerizations and to control the molar masses and the thermo-mechanical properties of the final polyurethane.
The research will be performed in close collaboration with three academic research groups, two from UBx (Bordeaux, France) and one from ULG (Belgium) having an expertise in the study of the solvation and reactivity of carbon dioxide with organic compounds and in the synthesis of polymers from renewable resources.
University of Bordeaux: Institut des Sciences Moléculaires (ISM) and Laboratoire de Chimie des Polymères Organiques (LCPO)
University of Liège: Center for Macromolecular Research (CERM)
Institut des Corps Gras (ITERG), Bordeaux