REVERSIBLE POLYMERS FORMED FROM SELF-COMPLEMENTARY MONOMERS USING QUADRUPLE HYDROGEN-BONDING

Units of 2-ureido-4-pyrimidone that dimerize strongly in a self-comple mentary array of four cooperative hydrogen bonds were used as the asso ciating end group in reversible self-assembling polymer systems. The u nidirectional design of the binding sites prevents uncontrolled multid irectional association or gelation. Linear polymers and reversible net works were formed from monomers with two and three binding sites, resp ectively. 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 architecture s can be formed, for use in, for example, coatings and hot melts, wher e a reversible, strongly temperature-dependent rheology is highly adva ntageous.