Abstract
Enthalpy and volume relaxation data measured on atactic poly(methyl methacrylate) and its blends with poly(ethylene oxide) are used to calculate an aging bulk modulus, Ka, tentatively defined as the derivative (∂ h∂ v)T . The Ka values are mainly lower than the corresponding bulk modulus data determined directly with a piston-type PVT-device. On the whole, however, the Ka values can be considered as lying close to the moduli measured in the liquid state. This notion is supported by Ka data measured on amorphous selenium, which has a significantly lower compressibility in the liquid state than common amorphous polymers. The results are discussed in terms of thermodynamics of irreversible processes using a single internal variable, yet without arriving at suitable expression for the enthalpy/volume derivative.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
