Viscoelastic properities of cross-linked solutions of poly (β-hydroxyethyl methacrylate) in diethylene glycol. V. Influence of secondary low-temperature transitions

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Abstract
The influence of secondary low-temperature dispersions on the storage and loss compliances of four poly(β-hydroxyethyl methacry-late) solutions in diethylene glycol was studied by comparing previously published double-transducer data with isochronal torsion pendulum data measured starting from the temperature of liquid nitrogen. It was found that the contribution of the main transition as observed in the storage compliance J'p decreased with increasing swelling degree of the samples. For a sample swollen to volume fraction of polymer v2 = 0.168, log Jp changes only about one decade, from −6 to −7; the further decrease of log J′p from −7 to −10.5 corresponds to the secondary low-temperature dispersion characteristic for polar side chains—polar diluent systems. For the latter dispersion the Arrhenius plot obtained using the double-transducer data gave δH = 24 kcal/mole. It was concluded that in some special cases the role of low-temperature secondary dispersions can be of primary importance in influencing the changes of storage and loss compliance. The contribution of the secondary β relaxation (as shown in earlier work on methacrylate polymers) and the influence of the low-temperature dispersion arising in polymethacrylate-diluent systems (β(SW) dispersion) studied in this paper were distinguished.