| Abstract: | Polyurethane (PU) anionomers were prepared as aqueous dispersions using dimethylol propionic acid (DMPA) as the stabilizing moiety. The principal diols used were polytetrahydrofuran of molecular weight 1000 (PTHF1000) and cyclohexane dimethanol (CHDM). The diisocyanates used in this study were isophorone diisocyanate (IPDI), hydrogenated methylene bisphenylene diisocyanate (H12MDI), tetramethylene xylene diisocyanate (TMXDI), hexamethylene diisocyanate (HDI), and a 50 : 50 blend of IPDI and HDI. All these samples were neutralized using triethylamine (TEA) and chain-extended using hydrazine monohydrate. The dispersions were prepared at a NCO/OH ratio of 2 so that a comparison of their structure–property relationships could be made with respect to their mechanical and viscoelastic properties and solvent resistance. Also, two further samples were prepared of similar composition to the IPDI-based sample, but using poly (propylene glycol), PPG1000, and PTHF2000 polyols. The effects on the structure and properties of the PPG1000 and the higher molecular weight PTHF sample were compared with the PTHF1000 sample. Dynamic mechanical thermal analysis, tensile testing, solvent spot, and swelling studies were employed for the characterization of these materials. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2035–2044, 1997 |
