Phase reversal during water dispersion of polyurethane anionomer

A series of polyurethane anionomers (PUas) was synthesized from isophorone diisocyanate, polyneopentanediol adipate (P756), and hydrophilic dimethanol propionic acid (DMPA). The variation of electric conductivity and viscosity of such anionomers during water dispersion was followed. The results showed that the average diameter and polyindex of particles were reduced, the viscosity of dispersion was lowered, the time necessary for phase reversal became shorter, if the amount of DMPA or the temperature, at which the water dispersion was carried out, increased. DSC test revealed that the order of hard segments was disturbed after water dispersion. IR spectra demonstrated that, after the chain extender ethyl diamine was added into the PUa dispersion, the hydrogen bonding of NH with carbonyls was stronger, if the dispersion temperature and the mass fraction of DMPA increased. (c) 2005 Wiley Periodicals, Inc.