A STUDY OF COLORED SILOXANE-BASED POLYURETHANE IONOMER

The reaction of dye with toluene diisocyanate and dimethyldichlorosila ne in the presence of other additives to form a colored siloxane-based polyurethane (PU) ionomer has been proven to occur by infrared spectr a. In aqueous solution, the number-average particle size for the color ed siloxane-based PU ionomer was found to increase with an increase in the NCO-to-OH ratio, dye concentration, and dimethyldichlorosilane co ncentration, as a result of increased free volume of the ionomer molec ules. It is worthy to note that the amount of air diffusing into the f ilm cast from colored siloxane-based PU ionomer was found to increase with an increase in the concentration of dimethyldichlorosilane instea d of raising the ratio of NCO to OH or the concentration of dye, as a result of the formation of more porosities. In addition, the tensile s trength of this film will be strengthened by raising the NCO/OH ratio or the concentration of dimethyldichlorosilane, whereas the elongation , on the other hand, can be substantially increased with increasing th e concentration of dye instead of increasing the concentration of dime thyldichlorosilane for use in the PU ionomer system. (C) 1998 John Wil ey & Sons, Inc.