Polymers for Making Superhydrophobic Surfaces

Patent metadata

Field	Value
Publication number	US-2016289462-A1
Application number	US-201415026930-A
Country	US
Kind code	A1
Filing date	Sep 26, 2014
Priority date	Sep 26, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The present disclosure relates to a process for making a comb-like polymer comprising the following steps of reacting an epoxy-functionalized monomer with a nucleophile comprising a C 8 -C 20 -alkyl group or halogen substituted C 8 -C 20 -alkyl group in the presence of an aqueous medium and polymerizing the reaction product. The comb-like polymer has functional groups on its backbone and long hydrophobic side chains. It can even be produced as a shell on a submicron sphere according to an alternative process according to the invention. The polymers obtainable by the inventive process can be polymerized with polyurethane prepolymers to achieve coating surfaces that show superhydrophobicity (see FIG.). Such coatings can have numerous applications especially in the aircraft industry for paints used on the airplane wings, because they avoid water droplet building.

First claim

1 . A process for making a comb-like polymer comprising the following steps:
(a) reacting an epoxy-functionalized monomer with a nucleophile comprising a C 8 -C 20 -alkyl group or halogen substituted C 8 -C 20 -alkyl group in the presence of an aqueous medium; and (b) polymerizing the reaction product.

2 . The process according to claim 1 wherein the epoxy-functionalized monomer is a glycidyl group carrying acrylate.

3 . The process according to claim 2 wherein the polymerization is a free radical polymerization.

4 . The process according to claim 3 wherein the nucleophile is an amine, hydroxyl or carboxyl compound.

5 . The process according to claim 1 wherein the epoxy-functionalized monomer is glycidyl methacrylate and the nucleophile is 1-hexadecylamine.

6 . The process according to any of claims 1 to 5 wherein step (a) is run under controlled pH conditions.

7 . The process according claim 6 wherein the pH is about 1.0 to 2.0.

8 . . The process according to claim 6 wherein the pH is about 6.5 to 75.

9 . The process according to any of claims 1 to 5 wherein in step (a) a salt is added.

10 . The process according to claim 1 wherein the polymerisation of the reaction product of step (a) takes place in an emulsion.

11 . The process according to claim 1 or 10 wherein the polymerisation in step (b) is a copolymerisation with another polymer monomer in an oil in water emulsion and comprising another subsequent step which is a phase inversion treatment.

12 . A process for making a comb-like polymer comprising the following steps
(b) polymerizing an epoxy-functionalized monomer optionally in the presence of another monomer to form a polymer or co-polymer; and (a) reacting the polymer or co-polymer with a nucleophile comprising an C 8 -C 20 -alkyl group or halogen substituted C 8 -C 20 -alkyl group in an emulsion.

13 . The process according to claim 12 wherein a vinyl monomer is used in step (b).

14 . A comb-like polymer obtainable by a method according to any of claims 1 to 13 .

15 . A submicron sphere with a comb-like polymer shell obtainable according to the process of claim 11 or 14 .

16 . Use of the comb-like polymer according to claim 14 in a coating process characterized in that a polyurethane pre-polymer is cured in the presence of the comb-like polymer.

17 . The use according to claim 16 wherein the polyurethane prepolymer is first pre-cured in the presence of comb-like polymer obtainable according to the process of claim 8 and then fully cured in the presence of a thinner and a polymer obtainable according to the process of claim 7 .

18 . The use according to claim 15 wherein for the full curing a mixture of the polymer obtainable according to the process of claim 7 and the sphere obtainable according to claim 15 is used.

19 . A coating obtainable by the method of any of claims 16 to 18 .

20 . A. coating according to claim 19 additionally including additives for the increase of hydrophobicity.

21 . Use of a coating according to claim 19 or 20 as top coat on aircraft wings.

22 . Use of a coating according to claim 19 or 20 as water repellent surface coating of pipes or ship bodies.

Assignees

• Agency Science Tech & Res

Inventors

• Hong Liang
• Tay Siok Wei
• Pallathadka Pramoda Kumari
• Ng Yeap Hung

Classifications

• C09D125/04

  Homopolymers or copolymers of styrene · CPC title

• C09D133/14

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title

• C09D175/04

  Polyurethanes · CPC title

• C08F212/08

  Styrene · CPC title

• C09D125/14

  with unsaturated esters · CPC title