A simple route to deuterated polystyrene block copolymers by reverse iodine transfer polymerisation

Abstract

Deuterated polystyrene (d-PS), synthesised for the first time using RITP, and hydrogenous polystyrene (h-PS) were characterised using ¹H nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC) to compare their polymerisation behaviour. Using h-PS as a macro-initiator, block copolymers of hydrogenous polystyrene-block-deuterated polystyrene (hPS-b-dPS) were prepared for the first time using RITP. These block copolymers were analysed using SEC and liquid chromatography at critical conditions (LCCC) of h-PS to determine possible residual first blocks. At the LCCC conditions for h-PS a separation based on the isotopic effect was observed, where the hPS-b-dPS block copolymers eluted in SEC mode. In order to improve the separation, conditions were established where one component eluted in SEC mode while the other component eluted in liquid adsorption chromatography (LAC) mode. A separation was achieved where the hPS-b-dPS block copolymer was separated from the h-PS precursor. The two-dimensional liquid chromatography (2D-LC) fractionation revealed a third component that was not observed in the one-dimensional fractionations.