Thermal-history-dependent Phase Behavior of Ceramide Molecular Assembly in a UV-curable Acrylic Adhesive Resin

The structure and thermal behavior of a synthetic D-erythro-ceramide [NDS], (2S,3R)-2-octadecanoylamino-octadecane-1,3-diol (CER), molecular assembly in a UV-curable acrylic adhesive resin (acResin^®) were investigated by differential scanning calorimetry (DSC), polarized-light microscopy, and X-ray diffraction (XRD). CER in the resin was found to exhibit a thermal-history-dependent polymorphic phase behavior that is similar but not identical to that observed for pure CER. The melting temperatures of the in-resin CER samples were lower than those of pure CER samples. Maintaining a melt-quenched in-resin CER sample at 60°C for 5-6 days induced a transformation from a metastable phase to a stable phase, where CER formed an ordered lamellar structure. The lamellar structure differed from that observed in the stable solid phase of pure CER samples. The findings of this study are expected to be useful for developing new medical tapes or sheets with ceramides added to the adhesives to protect skin.