Polyurethane ionomers. Part I. Preparation, structure, properties and application
of anionic polyurethane or polyurethane-acrylic dispersions
Polimery 2004, No 7-8, 530
Several polyurethane anionomers have been synthesized in the reactions of toluilene (TDI) or isophorone diisocyanates, polyester or polyether polyols and dihydroxyacids. Urethane - isocyanate prepolymers have been extended with 1,6-hexamethyldiamine or terminated with 2-hydroxyethyl acrylate. They were eventually then copolymerized, in emulsion, with other acrylic monomers in the presence of free radical initiators. 1H NMR or IR spectra confirm the expected structures of PUR anionomers and introduction of polar ionic groups. GPC investigations showed that besides oligourethane anionomers also the components showing much higher molecular weights were present what influenced the viscosity or surface tension of aqueous dispersions prepared. The following properties of the products obtained in a form of coatings were investigated: dry substance content, hardness after seasoning, abrasion, flexibility, impact strength and gloss. The investigations done allowed to choose the dispersion based on TDI and oligo(oxylenecaprolactone)diol as the best one to produce the varnish coatings.
Keywords: polyurethane ionomers, varnish coatings, polyurethanes, polyacrylates, contact angle, rheological properties
Polyurethane ionomers. Part I. Preparation, structure, properties and application of anionic polyurethane or polyurethane-acrylic dispersions