Moisture-regulating microcapsule and its enhanced water vapor permeability of leather polyurethane coating

Abstract

A type of porous shell moisture-regulating microcapsules (MRM), was successfully prepared by self-assembly of chitosanand graphene oxide onto the surface of paraffin, followed by chemical precipitation of SiO2). The MRM was used to enhance the water vapor permeability (WVP) of polyurethane (PU) composite coating. The composite PU coating was facilely fabricated by mixing PU emulsion with the prepared MRM and applied in leather coating. The SEM and AFM of composite PU films confirmed that the MRM in PU increased the roughness of the composite films, enhancing the water contact angle. As a result, the WVP of the composite PU coating was effectively improved by MRM and exhibited a good balance between WVP and water resistance, maintaining the transparency and mechanical properties of the films. After the composite PU coating was coated on leather surface, the leather showed an improvement of WVP with slight increase in water resistance, indicating that the composite PU coating with MRM can be a promising candidate to improve the comfort of leather.