Polyurethane doped with low-concentration erbium

Polyurethane (PU) with lactate structures inits conformation can be used as a biological and biodegradablepolymer. Polyurethane lactate (PUL) was dopedwith small quantities of an erbium (Er3þ) complex, whichhindered the N¼N group. 2,20-Dihydroxyazobenzene wasused as a ligand for the Er3þ complex. PUL in the presenceof the used Er3þ complex caused water from the complexto be replaced by the polar structures from the polymer.These structures acted as crystallization germs for thestructuration of the PU matrix. As a consequence, both themechanical and thermal properties of the polymer wereimproved. The sample with the highest mechanical propertiescontained only 0.064 mmol of Er3þ complex/g ofsample. ?? 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:659–669, 2007Key words: FTIR; matrix; mechanical properties; metal-polymercomplexes; polyurethanes