Inverse gas chromatography for the study of one phase and two phase polymer mixtures

Experiment finds that, for a chlorinated polyethylene (chlorine content 62.1% by weight)/poly(ethyl methacrylate) blend, a negative value of χ′_{2 3} is obtained, which indicates compatibility. With increasing temperature, χ′_{2 3} increases towards zero as required by the lower critical solution temperature behaviour of polymer blends. For chlorinated polyethylene/poly(butyl acrylate) blends however the specific retention volume is a linear function of composition and a positive χ′_{2 3} results if calculated by the conventional theory. The magnitude of χ′_{2 3} is determined by the difference between the retention volumes of the pure polymers and decreases with temperature. This effect is assumed to be a result of phase separation during coating the blend onto the support. A theoretical treatment is developed to explain this behaviour.