Dynamic-mechanical and light scattering study of the glass transition of poly(vinylacetate) and a poly(vinylacetate) +poly(4-hydroxystyrene) blend

• Published in: The Journal of chemical physics 1994-02, Vol.100 (4), p.3258-3267
• Main Authors: Luengo, Gustavo, Ortega, Francisco, Rubio, Ramón G., Rey, Antonio, Prolongo, Margarita G., Masegosa, Rosa M.
• Format: Article
• Language: English
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.466416

The dynamics of poly(vinylacetate) (PVAc) and of a blend of PVAc and 20% in weight of poly(4-hydoxystyrene) have been studied in the glass transition region using dynamic-mechanical and photon-correlation spectroscopies. Both kinds of data show the overlapping of the main α relaxation with a faster one. The complex part of the elastic modulus shows the existence of a β′ sub-Tg transition overlapping with the α one in the high-frequency region. The light scattering data show some degree of overlapping of the α and β transitions. As a consequence, at least two Kohlraush–Williams–Watts terms are needed to describe the relaxation functions. The results show a good agreement with the predictions of the mode coupling theory except for the fact that the calculated critical temperature seems to be lower than the calorimetric glass transition temperature.