| abstract |
The present invention relates to polymers having dynamic urea bonds and more specifically to polymers having hindered urea bonds (HUBs) with fast hydrolytic kinetics. These urea bonds are aryl-substituted, i.e. aromatic-substituted hindered urea bonds, that demonstrate pH independent hydrolytic kinetics, such that they consistently and rapidly hydrolyze in water from pH 2 to 11. The urea bond dissociation for these materials is generally such that k−1>h−1, which is two orders of magnitudes faster than for aliphatic hindered ureas. The present invention also relates to hydrolytically reversible or degradable linear, branched or network polymers incorporating these HUBs and to precursors for incorporation of these HUBs into these polymers. The technology can be applied to and integrated into a variety of polymers, such as polyureas, polyurethanes, polyesters, polyamides, polycarbonates, polyamines, and polysaccharides to make linear, branched, and cross-linked polymers. Polymers incorporating these HUBs can be used in a wide variety of applications including for example, environmentally compatible packaging materials and biomedical applications, such as drug delivery systems and tissue engineering. In other embodiments, the HUBs can be used in self-healing polymers. |