Overcome oXYGEn iNhibition – Oxygen

Nowadays, about 45 % of the polymeric materials are produced by mean of free radical polymerization (FRP) processes. Considering the broadness of applications, all these materials prepared by radical polymerization are intrinsically highly vulnerable to inhibition by molecular oxygen, resulting in an incomplete cure, manifested particularly by a tacky upper surface, deteriorating the mechanical properties or in other cases resulting in a complete failure to cure. The problem of oxygen inhibition is completely universal to all free radical curing applications (initiated by light, heat or redox processes…). Therefore, the development of new synthetic strategies and/or additives enabling an efficient curing under air is a huge challenge. In this project, five complementary approaches aiming at addressing the oxygen inhibition issue are proposed for more sustainable and energy-efficient materials and processes. First, characterization of the oxygen inhibition in different polymerization processes will be carried out. In a second task, the combination of two polymerization modes i.e. radical and cationic polymerization could drastically improve the monomer conversion by combining FRP to the cationic polymerization insensitive to oxygen. In a third task, the development of oxygen-insensitive photoinitiators (PIs) will be proposed. This task is strongly related to the fourth one aiming at developing new additives favoring the oxygen consumption. Finally, these different approaches will be tested in industrial conditions by our partner i.e. Arkema (ANR PRCE). High value applications for these new oxygen-insensitive initiating systems will be provided by: i) the polymerization of renewable monomers for a more a sustainable chemistry and monomers of industrial interest (for both the coating and adhesive markets) and ii) the curing of composites.