CHARACTERIZATION OF MODEL URETHANES AND UREAS BASED ON HYDRO.GENATED METHYLENEDIPHENLDnSOCYANATE VIA SOLUTION AND SOLID STATE NMR SPECTROSCOPY

摘要

Models for hard-block segmented polyurethanes were prepared via a pre-polymer process.Urethane linkages were synthesized using hydrogenated methylenediphenyldiisocyanate (H12MDI) reacted with dimethylol propionic acid (DMPA) and hexanol,while urea linkages were synthesized using H12MDI and hexylamine.The resulting small molecules were then studied by solution and solid state 13C nuclear magnetic resonance (NMR) spectroscopy to determine the reaction coordinates,to investigate possible side reactions of allophantes or biurets,to document 13C and 'H spectra,and to document reaction times.