The rheological properties of polystyrene/poly(vinylmethylether) (PS/PVME) blend near the critical region and in the homogeneous region were investigated. The blend had a lower critical solution temperature (LCST) of 112°C obtained by a turbidity experiment using a light scattering (LS) apparatus at a heating rate of 1°C/h. Four different blend compositions (critical (30/70 PS/PVME by weight) and three off-critical (10/90, 50/50, and 70/30) as well as neat PS and PVME were prepared. For the critical composition, logarithmic plots of shear modulus (G 0 ) versus loss modulus (G 00 ) showed temperature dependence even in the homogenous region determined by LS, while those plots become temperature independent in the homogeneous region for off-critical compositions. Logarithmic plots of blend viscosity versus composition exhibited a negative deviation at constant temperature; however, these showed a maximum at a certain composition when the reference temperature is taken as fixed T ⫺ Tg (under approximately iso-free volume condition).
Посилання на статтю:
The rheological properties of polystyrene/poly(vinylmethylether) blend near the critical region and in the homogenous region / Jin Kon Kim, Hye Won Son // Polymer. – 1999. – N 40. – P. 6789–6801.