Study of oxygen-permeable polyurethane ionomer. II

Oxygen-permeable polyurethane ionomers with dimethyldimethoxysilane or dime thyldimethoxysilane have been successfully synthesized at our lab, and thei r ionomer structures have been proven by infrared spectra. In our previous paper,(1) it was found that the amount of oxygen permeated through the film made by a dimethyldichlorosilane polyurethane ionomer increased with incre asing the concentration of dimethyldichlorosilane. Presently, our experimen tal results also indicate that use of dimethyldimethoxysilane or dimethyldi ethoxysilane in preparing polyurethane ionomers does substantially raise th e amount of oxygen diffusing into the films made by these ionomers. These r esults suggest that use of dimethyldichlorosilane, dimethyldimethoxysilane, or dimethyldiethoxysilane, with strong hydrophilic property, in making pol yurethane ionomer will give better oxygen permeability of siloxane-based po lyurethane ionomers. It is interesting to point out that both tensile stren gth and the elongation of a siloxane-based polyurethane ionomer film become weaker as the concentration of dimethyldimethoxysilane or dimethyldiethoxy silane increases. This may be the result of intramolecular interaction of i onomer molecules, coupled with the reduction of the formation of hydrogen b onding between ionomer-ionomer molecules and between ionomer-water molecule s. (C) 2000 John Wiley & Sons, Inc.