RELAXATION IN SEMIINTERPENETRATING POLYMERS NETWORK OF LINEAR POLYURETHANE AND HETEROCYCLIC POLYMER NETWORKS

New semi-interpenetrating polymers (semi-IPN) of linear polyurethane ( PU) and heterocyclic polymer networks prepared by trimerized dicyanate of Bisphenol-A (TDCE) have been analyzed by dynamic mechanical spectr oscopy (DMS) in the 130-550 K temperature and 0.3-30 Hz frequency rang es. Single mechanical alpha(beta)-relaxations suggest a large-scale ho mogeneity ascribed to the affinity between TDCE and PU. Below the glas s transition temperature, the interpenetration affects the local molec ular motions as a consequence of modifications in the mutual local env ironments of pure components. (C) 1998 Elsevier Science B.V. All right s reserved.