NOVEL FLUORINE-CONTAINING ANIONIC AQUEOUS POLYURETHANES

Various amounts of fluorine-containing polyol (F-diol, MW = 3700) were introduced into the soft segment of anionic aqueous polyurethanes PUs to examine the effect of the F-diol on the properties of the anionic aqueous PUs. The hard segments in the anionic aqueous PUs consisted of 4,4'-methylene bis(cyclohexylisocyanate), dimethylolpropionic acid, and 1,4-cyclohexanediamine (cis/trans = 80/20). Both the mechanical and water resistance properties of the anionic aqueous PUs were improved after introducing small amounts of the F-diol in the soft segment of the aqueous PUs. This is due to the increased intermolecular forces and crystallinity as well as the hydrophobic characteristic of the F-diol. Thermal analysis of the F-diol modified anionic aqueous PUs by differential scanning calorimetry and dynamic mechanical analysis indicated that both intermolecular forces and crystallinity increased with increasing concentration of the F-diol. However, both the increased intermolecular forces and crystallinity could have an adverse effect on the interface adhesion.