Melting and recrystallization processes in a rubbery polymer detected by vapor sorption and temperature-modulated DSC methods

Series of successive absorption runs of n-hexane vapor in films of semi-crystalline poly(dimethylsilatrimethylene) at 25 °C are presented. Sorption overshoots were observed in the uptake kinetic curves of first series of absorption runs in as-prepared films. The said overshoots were absent in the second series of runs, conducted after desorption, while the sorption isotherms of the two series were identical. The overshoots are attributable to penetrant-induced melting and recrystallization phenomena. Strong support to this interpretation is given by temperature-modulated DSC data obtained from the pure polymer, which reveal similar thermally induced phenomena at slightly higher temperatures.