Characteristics and iso‐baric relaxation phenomenon of pmma monolayers with different molecular weights at different temperatures

Poly(methyl methacrylate) (PMMA) monolayers with different molecular weights at the air/water interface were investigated at three different temperatures. The monolayer characteristics of PMMA were studied in terms of surface pressure‐area per molecule (π‐A) isotherm and isobaric relaxation experiments. The results show that the π‐A isotherms of PMMA converge at 40°C regardless of molecular weight. The collapse pressure of PMMA monolayers decreases as the temperature is elevated. It was shown the area relaxation process of PMMA could be described by a model considering the nucleation and growth mechanisms. The simulation parameters of area relaxation of PMMA with different molecular weights at 8 mN/m are very similar, indicating similar mechanisms. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011