Synthesis and properties of water soluble polyurethanes based on poly(ethylene glycol)

Water soluble polyurethanes (WSPU)s have been prepared by polycondensation of isophorondiisocyanate and tolylene-2,4-diisocyanate with poly(ethylene glycol)s (PEGs) of molecular weights 400, 600, and 1,000. The physicochemical properties of the WSPUs depend on the hydrophilic-hydrophobic balance in their polymeric chain, i.e., the properties are determined by relative density of the hydrophobic diisocyanate residues in WSPU. X-ray and differential scanning calorimetry studies show that the WSPUs have a degree of crystallinity lower than that of the pure PEGs of the same molecular weights. Like the PEGs the WSPUs prepared form interpolymer complexes with polyacrylic (PAA) and polymethacrylic (PMAA) acids. These complexes are more stable than the (PEG.PAA) and (PEG. PMAA) complexes. The novel compounds can be considered as modified linear PEGs. (C) 2004 Wiley Periodicals, Inc.