Study of the transition phenomena of poly(alpha-n-propyl) methacrylates adsorbed on silica by inverse gas chromatography (IGC)

Inverse gas chromatography at infinite dilution was used in this paper to characterise the superficial and interfacial properties of solid substrates as oxides, polymers or polymers adsorbed on oxides. Especially, we studied the transition phenomena in PMMA and poly(alpha-n-alkyl) methacrylate adsorbed on silica or in their bulk phases. hi the case of PMMA (adsorbed on silica or not), the study of the evolution of RTInVn as a function of 1/T for different n-alkanes, proved that IGC technique allowed to determine with a,6, the transition temperature relative to beta-relaxation, T-g, good accuracy the various transition temperatures: T the glass transition temperature and T-1,T-1 the liquid-liquid transition temperature or order-disorder transition. The same study was also realised with poly(alpha-n-propyl) methacrylate. The glass transition temperatures of this polymer (C3) adsorbed in its bulk phase or on silica were determined. We also showed an important effect of the adsorption of polymer on oxide on the shift in the value of T-g.