A comparison of concentration-glasses and temperature-hyperquenched glasses:CO_2-formed glass versus temperature-formed glass

摘要

Prior work from this laboratory has reported anomalous differences in the viscoelastic responses between temperature-jump formed glasses and carbon dioxide pressure-jump or relative humidity formed glasses.In the present work,we investigate the anomalous behaviour further by examining the structural response of an epoxy resin after pre-annealing treatments.In particular,we have measured the volume change of amine-cured diglycidyl ether of bisphenol A after thermal and carbon dioxide pressure(PCO_2)treatments.Our results show that contrary to prior interpretations in the literature,a plasticizer quench is different from a temperature hyperquench.Consistent with our prior work,the CO_2-formed glass is more stable than the temperature-formed glass in spite of the former having a higher excess volume.Our new results show that the stability persists to above the nominal glass temperature,contrary to what happens in a temperature hyperquench.