The melting (T-m) and glass transition (T-g) temperatures of a series of ethylene (E) tetrafluoroethylene (TFE) copolymer (ETFE) have been found to show unique dependence on the TFE content with the minimal and maximal points. These behaviors have been interpreted successfully on the basis of the degree of alternation of E and TFE monomeric units along the skeletal chain. The melting point of a perfectly alternating copolymer is estimated to be 295 degrees C on the basis of the dependence of T-m using a modified Flory's equation. The corresponding T-g was estimated as 145 degrees C by applying a modified Gibbs Damnation's equation. (C) 2010 Elsevier Ltd. All rights reserved.