Dynamic Homogeneity by Architectural Design - Bottlebrush Polymers

摘要

The self-organization and dynamics of bottlebrush polymers consisting of poly(2-bromoisobutyryloxyethyl methacrylate) (PBiBEM) backbone and grafted n-butyl acrylate (PBA) chains are studied as a function of the side-chain length by X-ray scattering, dielectric spectroscopy, and rheology in relation to the respective homopolymers. All short-range correlations are dominated by the PBA side chains, whereas long-range correlations reflect the screening of the backbones by the side chains. Such correlations show up also in the segmental dynamics. The PBA segmental dynamics are slowed-down, whereas the backbone dynamics are plasticized by the side chains. Overall the bottle-brush architecture imparts dynamic homogeneity to the backbone and side-chain dynamics. Bottlebrush polymers exhibit short-range correlations dominated by the dense side chains and long-range correlations reflecting the screening of the backbones. Dielectric spectroscopy reveals that the architecture imparts dynamic homogeneity to the backbone and side-chain dynamics.