| 초록 |
The aim of this work was to enhance the water vapor permeability of bio-polyurethane thin film, whose essential application is as a non-microporous type of film in breathable fabrics, by hybridizing it with nano- and micro-sized titania ( $TiO_2$ ). The bio-polyurethanes were synthesized from 4,4-diphenylmethane diisocyanate (MDI) and a polyol mixture containing polyethylene glycol (PEG) and soybean oil-based polyol, that is, bio-glycols by the hydroxylation of soybean oils upto 25% by weight of bio-polyurethane. We studied the effect of hybridizing the bio-polyurethane films with hydrophilic nano- or micro-sized $TiO_2$ on their breathability by measuring the water contact angle and the water vapor permeability of the films; it was found to significantly enhance the permeability of the bio-polyurethane film. Further, nano- $TiO_2$ was more effective than micro- $TiO_2$ due to the higher surface area resulting from nano particles. On the other hand, it is expected that it would be possible to provide additive functionality to the bio-PU membranes due to photocatalytic effect of nano- $TiO_2$ . |
