Synthesis and microphase separation of diblock copolymers of styrene and p-chlorostyrene prepared by using N-oxyl capped macroinitiators

Abstract

Diblock copolymers of styrene and p-chlorostyrene (PS-b-PpClS) were prepared via chain extension polymerization of N-oxyl-capped polystyrene macroinitiators with p-chlorostyrene. The kinetics plots of the copolymerizations are approximately first order with respect to monomer concentrations. The addition of p-chlorostyrene to the macroinitiators yields microphase separated polymers, which were studied by transmission electron microscopy and small-angle X-ray scattering. The results on the morphology of the block copolymers obtained by both methods are in excellent agreement. A variety of block copolymer structures ranging from highly ordered hexagonally packed cylinders or systems with the simultaneous occurrence of cylinders and lamellae to relatively disordered spheres is observed.