Miscibility of poly(vinyl chloride) and poly(phenyl methacrylate)

The phase behaviour of poly(vinyl chloride)/poly(phenyl methacrylate) blends has been investigated by glass transition temperature $(T_g)$ and proton spin lattice relaxation time $(T_1\rho(^1H))$ measurements. The results indicate that the domain sizes are between 3 and 15 nm. The miscibility in this system stems from the presence of weak hydrogen bonding between the components, as is evident from the Fourier transform infrared spectroscopic studies of the model compounds. The trend in the miscibility of poly(vinyl chloride) blends with related polymethacrylates containing similar, bulky substituents like cyclohexyl and benzyl groups has been investigated. The miscibility could not be explained in terms of a steric effect as the sizes of the molar volumes of the repeat units did not show any perceptible trend. The modified neglect of diatomic overlap calculations on the model compounds, however, suggest that the interaction between the components is the predominant factor, thus explaining the miscibility trend in these systems