Title: POLYMERS FOR MAKING SUPERHYDROPHOBIC SURFACES

 Number/Link: WO2015/047196

Applicant/Assignee: AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH

Publication date: 2-04-2015

“Gist”: A comb polymer with hydrophobic side chains and an isocyanate-reactive backbone is reacted with an NCO-ended prepolymer.

Why it is interesting: Superhydrophobic surfaces show a contact angle (vs water) of 150° or more. Water therefore forms almost perfectly spherical droplets on such a surface which easily roll off: the so-called “lotus-effect”. Superhydrophobic surfaces can find important applications in e.g. automotive and aviation industries. The current invention relates to a superhydrophobic coating composition comprising a hydrophobic comb-polymer having an NCO-reactive backbone together with a polyurethane prepolymer.  The comb polymer is prepared by alkylating an unsaturated epoxy monomer with a nucleophile comprising a C8 to C20 alkyl group, followed by polymerization. The resulting comb polymer can then be combined with an NCO-ended polyurethane prepolymer to make a superhydrophobic coating composition. In an example hexadecylamine is reacted with glycidylmethacrylate resulting in 3-(hexadecylamino)-2-hydroxypropylmethacrylate which is then polymerized into a comb-like polymer. After separation and drying the comb polymer is combined with a commercial (solvent-based) polyurethane prepolymer to make the coating composition.

Glycidylmethacrylate