Poly(styrene-graft-hyperbranched polyglycidol): synthesis and solution behavior of a hyperbranched polyelectrolyte

Abstract

This work presents a three-step synthetic procedure to obtain a hypergrafted copolymer composed of a glassy backbone with flexible branched pendant segments. The desired hypergrafted structure was obtained by using a polyfunctional macroinitiator, linear poly(styrene-co-4-hydroxystyrene), to yield polystyrene-graft-hyperbranched polyglycidol with randomly placed branch junctions. Atomic force microscopy, dynamic light scattering, and viscometry probed the aggregation and viscometric behavior of the polymer in DMF and DMF–LiBr solutions. The polymer exhibited polyelectrolyte behavior demonstrated by a large increase in the reduced viscosity prior to neutralization with LiBr salt. Additionally, conformational changes were observed by dynamic light scattering in both the average aggregate size and aggregate population with the addition of LiBr salt.