Study of the miscibility of poly(styrene-co-4-vinylbenzoic acid) with poly(ethyl methacrylate) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] by inverse gas chromatography.
Poly(styrene) is immiscible with poly(ethyl methacrylate). The introduction of a small amount of 4-vinylbenzoic acid units along poly(styrene) chains (PS-VBA) enhanced its miscibility with poly(ethyl methacrylate) (PEMA) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] (PEMA-DAE), as observed from the appearance of a single composition dependent glass transition temperature for each binary system using inverse gas chromatography. The negative values of the apparent polymer-polymer interaction parameter, chi(23)app, determined with different families of molecular probes, for three blend compositions and over a range of temperature confirm quantitatively the miscibility of these blends. The chi(23)app values for PEMA(PS-VBA) and (PEMA-DAE)-(PS-VBA) blends are dependent of the chemical nature of the probes, the temperature and the blend composition.
Studies of polystyrene-polybutadiene blend system by inverse gas chromatography
Inverse gas chromatography (i.g.c.) has been used to calculate thermodynamic interaction parameters of polystyrene (PS) and polybutadiene (PBD) with 15 different probes of varying polarities at 155, 165, 175 and 185°C. Polymer-polymer interaction parameters were also evaluated at five different compositions of PS-PBD blends and were found to show marked probe dependence. Using various approaches such as those given by Horta et al., by Sanchez and by Chee, the experimental data have been analysed to provide probe-independent interaction parameters. It is shown that rearrangement of an equation due to Su and Patterson explains the Δχ effect and gives probe-independent interaction parameters by a more simplified method.
Polymer-polymer interaction parameter in the presence of a solvent
Proposition d'une methode de calcul du parametre d'interaction a partir de mesures experimentales en utilisant la theorie d'equation d'etat qui donne un veritable potentiel chimique ternaire au lieu du potentiel approximatif utilise usuellement. Application a des donnees de chromatographie gazeuse inverse et de sorption de vapeur de la litterature pour les systemes PS/PVME avec differents solvants