Synthesis and aqueous solution behavior of water-soluble polyurethane (IPDI-PPG-DMPA) resin

摘要

Two types of polyurethane (PU) resins were synthesized by polyaddition of isophorone diisocyanate (IPDI), poly (propylene glycols: PPG-750 and PPG-2000), and 2,2-bis(hydroxymethyl)propionic acid (DMPA). Chemical structure of PU was confirmed by H-1 and C-13 NMR analysis. The PU resins were found to be water-dispersible or soluble by neutralization of carboxylic acid groups in DMPA. Aggregate formation behavior of the PU and solubilizing ability for hydrophobic probe (pyrene) were investigated at 100% neutralization.. Average aggregate sizes of the PU resins measured by photon correlation spectroscopy showed large values (ca. 25-120 nm). The aggregate sizes were strongly affected by the concentration of the resin and total ionic strength in the aqueous phase. The PU resins showed superior solubilizing ability for pyrene in comparison with that of conventional short chain surfactant. Additionally, critical micelle concentration (CMC) of the PU resins obtained from pyrene fluorescence method showed extremely low values (<10(-3) mol/dm(3) water) and their aggregate numbers were 7.2 and 6.5 for PUR-750 and PUR-2000, respectively. [References: 20]