The polymer-polymer interaction parameters of STVPh/PPC blends were calculated by Hildebrand solubility parameter. Accordingly the miscibility of the blends was predicted. The segment motion and miscibility of blends were also investigated by electron spin resonance(ESR) spin probe method. ESR spectra were measured as a function of temperature and the hydroxyl content in STVPh. For all blends, two spectral components with different rates of motion, a "fast" and a "slow" component were observed. This result showed that the nitrooxide radical existed in two different matrixes, a more flexible PPC-rich and a more rigid STVPh-rich micro domain. In addition, T 5mT and rotational correlation time τ c and activation energy E a were obtained from ESR spectra, which indicated the hydrogen bonding between the carbonyl and ether oxygen in PPC and the hydroxyl in STVPh was enhanced with increasing the hydroxyl content in STVPh.
