Self-Assembled Structures of Diblock Copolymer/Homopolymer Blends through Multiple Complementary Hydrogen Bonds

Abstract

A poly(styrene-b-vinylbenzyl triazolylmethyl methyladenine) (PS-b-PVBA) diblock copolymer and a poly(vinylbenzyl triazolylmethyl methylthymine) (PVBT) homopolymer were prepared through a combination of nitroxide-mediated radical polymerizations and click reactions. Strong multiple hydrogen bonding interactions of the A···T binary pairs occurred in the PVBA/PVBT miscible domain of the PS-b-PVBA/PVPT diblock copolymer/homopolymer blend, as evidenced in Fourier transform infrared and 1H nuclear magnetic resonance spectra. The self-assembled lamellar structure of the pure PS-b-PVBA diblock copolymer after thermal annealing was transformed to a cylinder structure after blending with PVBT at lower concentrations and then to a disordered micelle or macrophase structure at higher PVBT concentrations, as revealed by small-angle X-ray scattering and transmission electron microscopy.

Keywords

• self-assembly
• strong hydrogen bonding
• nucleobases
• block copolymers