A COUNTERINTUITIVE OBSERVATION CONCERNING HYDROGEN-BONDING IN POLYMERBLENDS

It has been determined from an infrared analysis of miscible blends of n-butyl methacrylate-co-4-vinylphenol and styrene-co-2-vinyl pyridine copolymers that the fraction of hydrogen-bonded carbonyl groups actua lly increases with temperature. At first glance, this is counterintuit ive, but it is entirely consistent behaviour for a multicomponent hydr ogen-bonding system containing competing acceptor groups that have dis parate enthalpies of hydrogen bond formation. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.