Glass transition induced by solvent desorption for statistical MMA/nBMA copolymers — Influence of copolymer composition

An experimental study of the glass transition induced by solvent desorption has been performed for a series of Methyl methacrylate (MMA)/n-butyl methacrylate (nBMA) statistical copolymer films. The glass transition temperature of the dry homopolymers, PMMA and PnBMA, are, respectively, about 105 and 7°C above the temperature of the experiment, so that the glass transition domain can be analyzed in detail by varying the solvent concentration and the copolymer composition. A strong coupling was found between drying dynamic and stress relaxation. In particular, the quantitative analysis of the desorption isotherms based on the Leibler–Sekimoto approach led to a bulk modulus K that increases as the proportion of nBMA increases, contrary to the behavior of dry annealed samples.