Study of some polyurethane elastomers using electrical methods

A study of some poly ether/ester urethanes has been carried out using electrical methods, viz. dielectric spectroscopy (400–105 Hz), dc conductivity, and dc step‐response techniques. X‐ray diffraction and thermal analysis also are used for characterization of the samples. The studies indicate a hard‐segment glass transition Tgh around 318–322 K in addition to a soft‐segment glass transition around 233–270 K. The breakage of hydrogen bonding mainly starts above Tgh. The studies also show a hard‐segment melting around 1.5–1.8 Tgh, but do not reveal any soft‐segment melting except in the case of the polyetherurethane sample. © 1994 John Wiley & Sons, Inc. Copyright © 1994 John Wiley & Sons, Inc.