Controlled step-growth polymerization

Abstract

Conjugated polymers are attractive components of modern plastic electronics and photovoltaic devices. They are synthesized mainly through a step-growth polymerization (SGP) mechanism. However, due to the uncontrollable characteristic of classical SGP, this effort leads to batch-to-batch variations in solubility, uncontrolled molecular weight, and broad polydispersity of the polymers obtained, thus, severely limiting their processing properties and performance. Here we demonstrate a general theoretical model of controlled SGP process by examining the possibility of the polymer chains further involvement in the SGP and how this correlated with their respective molecular weights. Subsequently, we proposed a practical method by which the SGP system was confined in nano-sized reactors. This method enabled the synthesis of a variety of polymers, having precisely controlled molecular weights with narrow polydispersity. We anticipate that this venture would exemplify a starting point for a more sophisticated molecular and structural design of functional polymers in widespread applications.