Volume and enthalpy relaxation in a-PMMA after temperature up-jumps
- 70 Downloads
the volume and enthalpy relaxation in a-PMMA subjected to temperature jumps in tg region has been analysed. The measured H and V data were compared with respect to aging time and proportionality between them as a slope of (∂H/∂V)T dependencies has been found. According to previous works the slope was identified as an apparent bulk modulus, Ka. This method is applied to aging following temperature up-jumps after consolidation periods of varying lengths. the main finding is a marked increase of Ka with consolidation time, approaching a limiting value in an asymptotic fashion.
Unable to display preview. Download preview PDF.
- 2.R. N. Haward and R. J. Young, The physics of glassy polymers, second edition, Chapman and Hall, London 1997, p. 85.Google Scholar
- 8.P. Slobodian, V. Pelíšek, J. Kubát and P. Sáha, SPE ANTEC Tech. Papers, 59 (2001) 1501.Google Scholar
- 9.P. Slobodian, J. Vilčáková and P. Sáha, SPE ANTEC Tech. Papers, 60 (2002) 3874.Google Scholar