DIELECTRIC AND MECHANICAL RELAXATION IN PMPS, BMC AND THEIR MIXTURES

Dielectric and dynamical mechanical measurements have been performed o n mixtures of the small molecule glass-forming liquid 1,1-bis(p-methox yphenyl) cyclohexane (BMC) with poly(methylphenylsiloxane) (PMPS). Ear lier measurements had indicated that the BMC dynamics are modified in a very interesting way by the presence of the polymer, despite the equ ivalence of their glass transition temperatures, T-g. By varying the m olecular weight of the polymer (and hence T-g), the BMC mobility is an omalously enhanced in mixtures of high T-g PMPS. An interpretation for these results based on the coupling model of relaxation is suggested.