Reversible Polymers Formed from Self-Complementary Monomers Using Quadruple Hydrogen Bonding

TLDR

Units of 2‑ureido‑4‑pyrimidone that dimerize strongly via a self‑complementary array of four cooperative hydrogen bonds were used as the associating end group in reversible self‑assembling polymer systems. The unidirectional design of the binding sites prevents uncontrolled multidirectional association or gelation. Linear polymers and reversible networks were formed from monomers with two and three binding sites, respectively, and the thermal and environmental control over lifetime and bond strength allows tunable properties such as viscosity, chain length, and composition, enabling polymer networks with thermodynamically controlled architectures for applications like coatings and hot melts where reversible, temperature‑dependent rheology is advantageous.

Abstract

Units of 2-ureido-4-pyrimidone that dimerize strongly in a self-complementary array of four cooperative hydrogen bonds were used as the associating end group in reversible self-assembling polymer systems. The unidirectional design of the binding sites prevents uncontrolled multidirectional association or gelation. Linear polymers and reversible networks were formed from monomers with two and three binding sites, respectively. The thermal and environmental control over lifetime and bond strength makes many properties, such as viscosity, chain length, and composition, tunable in a way not accessible to traditional polymers. Hence, polymer networks with thermodynamically controlled architectures can be formed, for use in, for example, coatings and hot melts, where a reversible, strongly temperature-dependent rheology is highly advantageous.