Influence of Cure Systems on Dielectric and Viscoelastic Relaxations inCrosslinked Chlorobutyl Rubber

摘要

The temperature and frequency-dependent Young's modulus and loss tangent havebeen examined as functions of cure systems and plasticizer loading in chemically crosslinked butyl and chlorobutyl rubbers. The crosslinked materials exhibited thermorheologically simple behavior. Dielectric permittivity and loss were measured as functions of frequency and temperature. The viscoelastic and dielectric behaviors were significantly influenced by the type of crosslinking system and by plasticizer loading. The Kolrausch-Williams-Watts 'stretched exponential' function was found to be a reasonable fit to both the dielectric and dynamic mechanical spectra. The effects of molecular motions and cooperative behavior upon the two types of relaxations have been discussed.... Dielectric spectroscopy, Young's modulus, Kolrausch-Williams-Watts function, Cure systems, Chlorobutyl rubber, Cooperative relaxations.