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Keywords:

  • amphiphilic wetting;
  • contraphilic wetting;
  • copolyoxetanes;
  • polyurethanes;
  • surface modification

Abstract

A conventional MDI-BD-PTMO polyurethane is modified using 2 wt% polyurethanes (U) having copolyoxetane soft blocks with hydrophobic 3F, CF3CH2OCH2— and hydrophilic MEn, CH3O(CH2CH2O)nCH2—, n = 3, 7) side chains. In contrast to neat 3F-co-MEn-U, 2 wt% 3F-co-MEn-U compositions have physically stable morphologies and wetting behavior. Surface composition (XPS) and amphiphilic or contraphilic wetting are controlled by the 3F-co-MEn polyoxetane soft block architecture and MEn side chain length. Importantly, θrec can be tuned for 2 wt% 3F-co-MEn-U compositions independent of swelling, which is controlled by the bulk polyurethane. AFM imaging leads to a new morphological model whereby fluorous/PEG-hard block nanoaggregates combine to form near surface features culminating in micron-scale texturing.