Viscoelastic properties of glass-forming polymers
- 5 Downloads
The effects of time, temperature, physical ageing, and non-linear stresses on the viscoelastic properties of glass-forming polymers are analysed by using our molecular theory of glasses. The drastic slowing down of the relaxation processes from the liquid state to the glassy state can be explained in terms of the temperature-dependent physical ageing rate. We find that the loss tangent decreases with ageing time whose effect, however, diminishes at longer loading times. In the non-linear viscoelastic range, the theory also predicts that the stress relaxes faster in shear than in tension.
KeywordsAgeing Time Loss Tangent PVAc Glassy State Physical Ageing
Unable to display preview. Download preview PDF.
- 4.R. KOHLRAUSCH, Am. Phys. (Leipzig) 21 (1847) 393.Google Scholar
- 10.D. G. FESKO and N. W. TSCHOEGL, J. Polym. Sci. C35 (1971) 51.Google Scholar
- 11.L. C. E. STRUIK, “Physical Ageing in Amorphous Polymers and Other Materials” (Elsevier, Amsterdam, 1978).Google Scholar
- 13.M. CIZMECIOGLU, R. F. FEDORS, S. D. HONG and J. MOACANIN, Polym. Preprints 21 (2) (1980) 31.Google Scholar
- 16.S. TURNER, in “The Physics of Glassy Polymers”, edited by R. H. Haward (Wiley, New York, 1973) p. 243.Google Scholar
- 20.B. HARTMANN, J. Rheol. 30 (1986) 894.Google Scholar