DYNAMIC MECHANICAL ANALYSIS OF SULFONATED POLYURETHANE IONOMERS

Dynamic mechanical analysis, using a flat-spring to support the sample, was conducted to study the properties of polyurethane ionomers prepared from poly (epoxy chloropropane) as polyol. The effects of the soft segment length and ionization level on the properties were studied. For the unionized polyurethane, the soft and hard segments had good compatibility and little phase separation was found due to the high polarity of the polyol. For the shorter hard segment ionomers, as the ionization level increased, the matrix T(g) rose due to the increase in the compatibility of hard and soft segments. For the longer ionized hard segment ionomers, the aggregating tendency of ion pairs enhanced phase separation. Quenching or annealing the samples showed that clusters existing in bulk materials did not dissociate below the degradation temperature and multiplets can dissociate or transform to clusters below 150-degrees-C.