Waterborne polyurethane cationomers synthesized from 4,4’-methylenebis(phenyl isocyanate) or isophorone diisocyanate, polyesters and N-methyl or N-butyldiethanolamine — analysis of the structure and selected properties of the obtained coatings
2012; Industrial Chemistry Research Institute; Volume: 57; Issue: 11/12 Linguagem: Inglês
10.14314/polimery.2012.799
ISSN0032-2725
Autores Tópico(s)Antimicrobial agents and applications
ResumoPolyurethane cationomers were synthesized in the reaction of MDI, IPDI, polyesters and tertiary aliphatic amines, which were incorporated into the prepolymer and converted to alkylammonium cations by reacting with formic acid or butyl bromide. The obtained isocyanate prepolymers were extended in aqueous medium using 1,6-hexamethylenediamine resulting in the formation of stable aqueous dispersions. Chemical structures of the synthesized cationomers were confirmed by 1H NMR spectroscopy. Attempts were made to quantitatively evaluate the polarity of coatings made from them using specially calculated for that purpose kcalc. parameter. The surface free energy (SFE) of the obtained coatings was determined using van Oss — Good and Owens — Wendt models as well as contact angle measurements of cationomer surfaces by means of standard liquids with various polarity. The effect of chemical structure and polarity of polyurethane cationomers on SFE as well as on its polar and acid-base components was discussed. It was concluded that these parameters are highly influenced by both diisocyanate and polyester type as well as molecular weight and ionic segment structure. Coatings with low hydrophobicity (SFE about 38 mJ/m2) were prepared from the cationomers made from MDI and poly(ethylene adipate) diol 1000, containing ionic groups obtained by incorporation of N-butyldiethanolamine together with butyl bromide into the polyurethane chains.
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