Innovative methods of polymerization of “less-activated monomers” (LAMs)

The main goal of the project is the use of a new, innovative method of polymer synthesis based on the photo- and photochemically-induced polymerization conducted under high pressure conditions. The project aims to investigate the impact of high pressure on polymerizability and reaction kinetics of a specific group of so-called “less-activated monomers” possessing ionic and non-ionic character and additionally characterized by the presence of sterically congested functional groups in their structure. Moreover, the use of compression of the reaction system and light as both the freeradical generator and mediator of polymerization will help to reduce or eliminate defects in classical free-radical polymerization (FRP) and controlled polymerization methods (CRP). In the case of FRP, it will be possible to reduce the dispersity of the resulted polymers, whereas in the case of CRP methods, to increase the reaction rate and obtain high molecular weight polymers. In addition, the project provides for the determination of the impact of high pressure on the physico-chemical and rheological properties (intrinsic viscosity, thermal stability, stress relaxation) of the produced macromolecules, as well as the creation of direct correlation between their parameters, e.g. the effect of molecular weight on stress relaxation and viscoelastic or thermodynamical properties of polymers). The “less-activated monomers” such as N-vinylimidazoles, N-vinylpyrrolidone, vinyl acetate, or N-vinyltriazoles and N-vinylcarbazole are an interesting group of compounds that have found application in many fields of science including medicine, biochemistry as well as electrical and optoelectronics. These monomers, due to their chemical structure (unconjugated vinyl group) are characterized by lower activity and polymerization in comparison to the group of “more-activated monomers (MAMs)”, such as (meth)acrylates and styrene derivatives. The above properties make it impossible to obtain high monomer conversions, as well as polymers with a high degree of polymerization as a result of polymerization of LAMs CRP methods, which results in low or moderate molecular weights. In this project, selected monomers from the LAMs group, e.g. N-vinylpyrrolidone and ionic and non-ionic N-vinyltriazoles, which additionally will contain sterically hindered functional groups, will be subjected to direct photo- and/or photochemically initiated high-pressure conventional and controlled polymerizations. This will allow obtaining macromolecules with strictly defined parameters by applying the metal-free method and investigating the effect of high pressure on their polymerizability. Additionally, it is worth paying attention to one of the research aims included in the project, i.e. to create a direct relationship between the basic parameters of the polymers. Recently, understanding the correlation between basic properties of polymers including those possessing features of poly(ionic liquid)s e.g. intrinsic structure and thermomechanical and rheological properties or conductivity have aroused the attention of scientists. Moreover, for this purpose polymers with well-defined structures and targeting specific properties are absolutely required. In this context, one can mention that there is a lot of important information about the behavior of ionic polymers missing in the literature. Just to remind that there are only a few papers on the evolution of the glass transition temperature vs molecular weight in these materials. Once polymers of well-defined structure and narrow dispersities are synthesized one can open discussion about the mechanisms of charge transport in ionic polymers e.g. ionic poly(N-vinyltriazoles) or mechanism of release of drugs from polymer matrices in biocompatible polymers such as poly(N-vinylpyrrolidone), which is a matter of current investigations. One can add that this point seems to be crucial in better designing and development of polymers of enhanced conductivity for possible applications as solid state electrolytes or polymers characterized by extended release time in controlled drug delivery systems.