The gelation of several samples of atactic polystyrene (aPS) in CS2 is studied by rheological methods. The Young's modulus and the loss and storage moduli are measured as a function of temperature in the sol and gel phases. In the sol phase the concentration dependence of the plateau modulus, Gr~, is found to be in good agreement with the theoretical predictions. The sol-gel transition is accompanied by an abrupt increase of GN, which shows the formation of additional entanglements with respect to the sol. For temperatures, T, below the gelation temperature, Tg?l , G N does not vary with temperature and the gel seems to reach a final structure at T = Tgel- 10°C. These behaviours, which are independent of the aPS molecular weight, are discussed in relation to other experimental investigations (phase diagram, anisotropic light scattering, neutron scattering)
Посилання на статтю:
Viscoelastic properties of thermoreversible gelation of atactic polystyrene / Noureddine Lehsaini, Rene Muller, Gilbert Weill and Jeanne Francois // Polymer. – 1994. – Vol 35. – P. 2180-2184.