THERMAL-DIFFUSIVITY AND CONDUCTIVITY OF PMMA PC BLENDS/

A miscible PMMA/PC blend was prepared by a rapid casting method, and i ts miscibility was confirmed by d.s.c. The specific heat capacity of t he two-phase blend (5/5) was larger than that of the one-phase blend. The thermal diffusivity and the conductivity of the blend (5/5) slight ly decreased with the increase of temperature up to 450-460 K (LCST), and then decreased abruptly with increasing of temperature. The therma l diffusivity at solid state was always smaller than the one estimated by the linear relation with PC content, while in liquid state it alwa ys changed linearly with PC content. On the other hand, the experiment al thermal conductivity in the liquid state was always smaller than th e value estimated by the linear relationship with PC content, while in the solid state it changed linearly. Finally, we discussed adaptabili ty of prediction equations appearing in literature to the conductivity . The Filippov, NEL and power law equations were found to describe ade quately the thermal conductivities of PC/PMMA blends in liquid and sol id states. (C) 1997 Elsevier Science Ltd.