Ethyl cellulose(EC)/cellulose acetate(CA) blends were prepared by solution blending. The (thermal) stability of the blends was observed by TG, and the compatibility of them was also studied by visco-(metry), refractive index, DSC and IR. The results show that the (refractive) index or the trait vicidity of the EC/CA solution is linearly dependent on the mass composition of the blend. At 50 and 0.01 g/mL concentration, EC and CA are almost completely miscible. A single T_g was observed for a series of blends, which was in between the T_g of pure EC and that of pure CA. The decomposition temperature of the EC/CA blend decreased with the increase of EC mass fraction in the blends. These results indicate that there is good compatibility (between) EC and CA, and the thermal stability of the blends is improved compared to that of pure EC.
