Confinement-induced Miscibility of Different PS-PMMA with Phenoxy Resin at the Air/Water Interface
Cheng-Da Lin and Wen-Ping Hsu
Department of Chemical Engineering, National United University, Miao-Li, Taiwan 360, R.O.C.
Abstract: The miscibility of the mixed monolayer behavior of different polystyrene-poly(methyl methacrylate) (PS-b-PMMA; PS-co-PMMA; PS-r-PMMA) with phenoxy resin(Phr) was studied from the measurements of surface pressure-area per molecule (π-A) isotherms using the Wilhelmy plate method with a KSV model mini-trough at three different temperatures (10℃, 25℃ and 40℃). The miscibility and non-ideality of the mixed monolayers were examined by calculating the excess surface area as a function of composition. The analysis of surface pressure-area per molecule (π-A) isotherms and excess area showed that mixed monolayers exhibit intermolecular interaction. When the pressure increases, the deviation can change from positive to negative. The mixed PS-b-PMMA monolayers exhibited mostly negative excess area among three studied PS-PMMA. The results of the mixed PS-co-PMMA monolayers were similar to those of mixed PS-r-PMMA likely because of close chain arrangements. Phr was found to be in the majority miscible with PS-PMMA at the air/water interface likely because of hydrogen bonding between Phr and PS-PMMA and confinement inducement.
Keywords: PS-PMMA, Phenoxy resin, Monolayer.