Structure-property relationships of polyurethane anionomer acrylates

Abstract

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 (Tgs) and hard segment glass transition (Tgh) in PU acrylate without diluent. However, with increasing DMPA (ionized) content, Tgh increased keeping Tgs 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 Tgh increased in the order of no diluent < TPGDA < TMPTA < NVP, and the tensile modulus, no diluent < TPGDA < TMPTA ≈ NVP. The rubbery plateau modulus (EN○) was well defined increasing in the order of no diluent < TPGDA < TMPTA. However, EN○ was not defined with NVP. Regarding the effect of TPGDA level, EN○ increased in magnitude, and Tgh shifted to the higher temperature with increasing TPGDA level. Copyright © 1996 Elsevier Science Ltd.