Surface modification of waterborne polyurethane

Fluorinated urethane oligomers (SMAs) having repeat unit identical to the hard segment of base polyurethane (PU) have been synthesized and blended with base PU prior to dispersion. XPS and static contact angle measurements showed that surfaces of dispersion cast film are significantly enriched with SMA although SMA and base PU were miscible in bulk phase showing a single glass transition temperature. AFM showed that surface roughness of the dispersion cast film increased over 13 times with the addition of SMA (15%) providing possible mechanism of increased water and oil resistance as well as low friction coefficient of the film.