Sorption and diffusion of ethanol vapor in polybutadiene/acrylonitrile, polybutadiene/styrene and polybutadiene based polyurethanes

The sorption and diffusion behavior of ethanol vapor in series of polyolefine based polyurethanes (PU) made from hydroxyl-terminated polybutadiene/acrylonitrile (HTBN), hydroxyl-terminated polybutadiene/styrene (HTBS) and hydroxyl-terminated polybutadiene (HTPB) were investigated by using the quartz-spring, DSC, FTIR and AFM. The equilibrium absorption reduced with increasing content of hard segments for all the three types of PUs. The values of the maximum absorption were in the order of HTBN > HTBS > HTPB based PU and related to their composition. The non-Fickian diffusion was confirmed and the sorption was discovered mainly in the hard segments. The HTBN based PU revealed different sorption and diffusion behavior from the other two, which was resulted from its hydrogen bonding not only between ethanol and hard segments but also soft segments. The morphologies of PUs before and after ethanol absorption were also compared. The HTBN based PU showed the most evident phase re-congregation after ethanol absorption.