Chain-End Functionalization with a Saccharide for 10 nm Microphase Separation: “Classical” PS-b-PMMA versus PS-b-PMMA-Saccharide

Abstract

Microphase-separated structures of block copolymers (BCPs) have attracted much attention as template materials for bottom-up nanofabrication. At the same time, chain-end modification has become a leading facile and efficient technique for fine-tuning the morphologies of microphase-separated structures generated from BCPs. Herein, we describe the preparation of well-defined polystyrene-block-poly(methyl methacrylate)s (PS-b-PMMAs) bearing highly hydrophilic mono/oligosaccharide moieties at their PMMA chain ends (SM-mono/oligosaccharides) as well as the impact of the mono/oligosaccharide on microphase separation behavior. PS-b-PMMAs were terminal-selectively transesterified using the titanium alkoxide of 6-azido-1-hexanol to introduce azido groups into the side chains of the terminal MMA units. The azido-functionalized PS-b-PMMAs were subsequently click reacted with ethynyl-functionalized mono/oligosaccharides to yield SM-mono/oligosaccharides. Small-angle X-ray scattering and microscopy experiments reveal ...