The non-equilibrium plasmas are weakly ionized gases containing electrons, neutral and charged molecular species, large clusters and nanoparticles. They are of key importance for advanced materials and nanostructures, for astrophysics and planetary atmospheres. They are governed by phenomena of highly diverse nature and take place on scales ranging from atomic size to that of plasma, including collisional processes between electrons and atoms/molecules leading to dissociations, excitations and ionizations, collisions of radicals and plasma-surface interactions. We are curious on how small secondary radicals produced through the interaction of the hydrocarbon plasma feed gas with electrons contribute, via ionization/recombination/dissociation processes, to the plasma properties. Quantum chemistry and scattering calculations will be carried out to investigate the reaction dynamics, to identify the reaction routes and to calculate the corresponding cross sections and rate coefficients.