Group contribution analysis applied to the Havriliak-Negami model for polyurethanes

Group contribution analysis (GCA) has been applied to many of the physical properties of polymers in the past. In this paper, GCA has been applied for the first time to the frequency dependent complex modulus of polymeric mat erials, which may be described in terms of the Havrialiak-Negami (H-N) equa tion. This approach has been tested on a set of polyurethanes for which the H-N parameters have been uniquely determined. It has been shown that the d ynamic mechanical behaviour of polymers may be described in terms of group additive relationships, at least for the 14 polyurethanes and nine structur al groups which were studied here. (C) 2000 Elsevier Science Ltd. All right s reserved.