Original Contribution

Colloid and Polymer Science

, Volume 291, Issue 4, pp 1031-1047

Open Access This content is freely available online to anyone, anywhere at any time.

Modelling the surface free energy parameters of polyurethane coats—part 1. Solvent-based coats obtained from linear polyurethane elastomers

  • Piotr KrólAffiliated withDepartment of Polymer Science, Faculty of Chemistry, Rzeszów University of Technology Email author 
  • , Jaromir B. LechowiczAffiliated withDepartment of Polymer Science, Faculty of Chemistry, Rzeszów University of Technology
  • , Bożena KrólAffiliated withDepartment of Polymer Science, Faculty of Chemistry, Rzeszów University of Technology

Abstract

Polyurethane elastomers coating were synthesised by using typical diisocyanates, polyether and polyester polyols and HO-tertiary amines or diols as a chain extenders. Mole fractions of structural fragments (κ exp) responsible for the polar interactions within polyurethane chains were calculated by 1H NMR method. Obtained results were confronted with the analogous parameter values (κ theor) calculated on the basis of process stoichiometry, considering the stage of the production of isocyanate prepolymers and reaction of their extension for polyurethanes. Trials of linear correlation between the κ exp parameters and surface free energy (SFE) values of investigated coatings were presented. SFE values were determined by Owens–Wendt method, using contact angles measured with the goniometric method. Based on achieved results, another empirical models, allowing for prediction the influence of the kind of polyurethane raw materials on SFE values of received coatings were determined. It was found that it is possible to regulate the SFE in the range millijoules per cubic metre by the selection of appropriate substrates. It has been found that use of 2,2,3,3-tetrafluoro-1,4-butanediol as a fluorinated extender of prepolymer chains is essential to obtain coatings with increased hydrophobicity, applied among others as biomaterials—next to diphenylmethane diisocyanate and polyoxyethylene glycol.

Keywords

Synthesis of the polyurethane coatings NMR spectroscopy Contact angles Owens–Wendt method Prediction of the surface free energy parameter Additive model of the surface free energy