Identification of Surface Radicals on Polymers

Abstract

Radicals can initiate reactions of chemically inert polymers. The incorporation of functional chemical groups to polymer surface can proceed via trapping or quenching reactions of polymer radicals with functionalized reaction partners. The density and reactivity of surfaces radicals governs the efficiency of the surface functionalization process. Subsequent to its termination, surviving, i.e. unreacted, radicals gain special importance since they exhibit a strong tendency to react with oxygen from the air. This generally will result in an unintended secondary functionalization of the polymer surface consisting of various oxygen groups. Therefore, the identification and quantification of radicals on polymer surfaces is becoming increasingly important for the on-going development of highly efficient and highly selective functionalization of polymer surfaces. This article reviews the state of the art of surface radical quantification. In addition, a new approach to the generation of radicals on polymer surface is presented.