Polymer, Vol.37, No.11, 2251-2257, 1996
Structure-Property Relationships of Polyurethane Anionomer Acrylates
Polyurethane (PU) ionomer acrylates and non-ionomer acrylates were synthesized from poly(propylene glycol) (PPG), isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), 2-hydroxyethylacrylate (HEA), and N-vinylpyrrolidone (NVP), tripropyleneglycol triacrylate (TPGDA), trimethylolpropane triacrylate (TMPTA), and were characterized in terms of water swell, mechanical, and dynamic mechanical properties in response to their structure. At fixed DMPA content (PPG/DMPA 8/2), neutralization caused an inward migration of soft segment glass transition (T-gs) and hard segment glass transition (T-gh) in PU acrylate without diluent. However, with increasing DMPA (ionized) content, T-gh increased keeping T-gs constant, together with an increase in equilibrium swell, tensile modulus, tensile strength, and the rubbery plateau modulus. At a fixed diluent level (20%), tensile strength and T-gh increased in the order of no diluent < TPGDA < TMPTA < NVP, and the tensile modulus, no diluent < TPGDA < TMPTA approximate to NVP. The rubbery plateau modulus (E(N) degrees) was well defined increasing in the order of no diluent < TPGDA < TMPTA. However, E(N) degrees was not defined with NVP. Regarding the effect of TPGDA level, E(N) degrees increased in magnitude, and T-gh Shifted to the higher temperature with increasing TPGDA level.