SYNTHESES AND PROPERTIES OF CROSSLINKED POLYURETHANE IONENES

Abstract

A series of crosslinked polyurethane (PU) ionenes were prepared for the purpose of obtaining PU with high water-absorbing power and good mechanical properties in bulk and even swollen state with water.
PU ionenes were prepared by prepolymer method. NCO-terminated (IT) prepolymer was prepared by the reaction of the mixture of poly (oxytetramethylene) glycol (PTMG) and poly (oxyethylene) glycol (PEG) with 4, 4′-methylenebis (phenylisocyanate) at NCO/OH=2/1 (mol). Amine-terminated (AT) prepolymer was prepared by the reaction of the IT-prepolymer with 2-dimethylaminoethanol at NCO/OH=2/1 (mol). Crosslinked PU ionenes were prepared by the reaction of AT-prepolymer with N, N, N′, N′-tetramethyl-1, 6-diaminohexane (THD) and 1, 6-dibromohexane (DBH) at different molar ratios. From swelling ratio and gel fraction, PU ionenes consisting of PTMG/PEG=6/4, 7/3 and THD/DBH=1/1.5 (N+ content=2.0wt% of PU ionene repeat units) were well suited for the present purpose.
PU ionenes were characterized by wide-angle X-ray, polarizing optical microscopy small angle light scattering, differential scanning calorimetry, dynamic mechanical properties, and stress-strain properties.
PU ionenes synthesized in this study will be useful for many applications such as water-sealant, wet pad, water retention material and so on.