Grafted polymers as oleophobic or hydrophobic coatings
An article of manufacture comprising a substrate and an outer polymer coating on the substrate. The polymer coating comprises an oleophobic grafted polymer comprising a crosslinked fluoroelastomer group. A perfluorinated polyether is grafted to the crosslinked fluoroelastomer group.
1. An article of manufacture comprising:
a substrate; and
an outer polymer coating on the substrate, the polymer coating comprising an oleophobic grafted polymer comprising,
a crosslinked fluoroelastomer group; and
a perfluorinated polyether grafted to the crosslinked fluoroelastomer group,
wherein the crosslinked fluoroelastomer group is crosslinked with an aminofunctionalized silane, the aminofunctionalized silane comprising an aminoalkylsilane-modified polysiloxane.
2. The article of manufacture of claim 1 , wherein the oleophobic grafted polymer comprises polymer units of formula I:
wherein FE is a fluoroelastomer group;
PFPE is a perfluorinated polyether group;
L is a linker;
m, n, and o are independently an integer from 1 to 10;
each incidence of R 1 and R 2 is independently a substituted or unsubstituted C 1 -C 6 alkyl; and
R 3 and R 4 are independently an optionally fluorinated C 1 -C 6 alkyl or an optionally fluorinated C 1 -C 6 alkoxy.
3. The article of manufacture of claim 2 , wherein the perfluorinated polyether (PFPE) group is an alkoxysilane-terminated perfluorinated polyether group.
4. The article of manufacture of claim 1 , wherein the substrate comprises a surface on which the outer polymer coating is formed, the surface being selected from the group consisting of a glass surface, a metal surface, a plastic surface, a ceramic surface and a textile surface.
5. The article of manufacture of claim 1 , wherein the substrate is a portion of an electronic device, a textile, a glass article, an automobile furnishing or a home appliance.
6. A process for making an article of manufacture, the process comprising:
crosslinking a fluoroelastomer with an aminofunctionalized silane;
grafting an alkoxysilane-terminated perfluorinated polyether to the crosslinked fluoroelastomer to form a oleophobic grafted polymer;
depositing a layer of the oleophobic grafted polymer on a substrate surface; and
curing the layer to form an oleophobic grafted polymer coating,
wherein the aminofunctionalized silane comprises an aminoalkylsilane-modified polysiloxane.
7. The process of claim 6 , wherein the oleophobic grafted polymer coating has a final structure comprising polymer units of formula I:
wherein FE is a fluoroelastomer group;
PFPE is a perfluorinated polyether group;
L is a linker;
m, n, and o are independently an integer from 1 to 10;
each incidence of R 1 and R 2 is independently an optionally fluorinated C 1 -C 6 alkyl; and
R 3 and R 4 are independently an optionally fluorinated C 1 -C 6 alkyl or an optionally fluorinated C 1 -C 6 alkoxy.
8. The process of claim 6 , wherein the crosslinking step is performed in the presence of the alkoxysilane-terminated perfluorinated polyether.
9. The process of claim 8 , wherein a ratio of the aminofunctionalized silane to the alkoxysilane-terminated perfluorinated polyether is in a range from about 0.5:1 to about 3:1.
10. The process of claim 9 , wherein an amount of the aminofunctionalized silane relative to the fluoroelastomer is in a range from about 2 pph to about 10 pph.
11. An article of manufacture comprising a surface and a polymer coating on the surface, the polymer coating comprising a compound that comprises polymer units of formula I:
wherein FE is a fluoroelastomer group;
PFPE is a perfluorinated polyether group;
L is a linker;
m and o are independently an integer from 3 to 8;
n is an integer from 1 to 10;
each incidence of R 1 and R 2 is independently a substituted or unsubstituted C 1 -C 6 alkyl; and
R 3 and R 4 are independently an optionally fluorinated C 1 -C 6 alkyl or an optionally fluorinated C 1 -C 6 alkoxy.
12. The article of manufacture of claim 11 , wherein L comprises a C 1 -C 6 alkyl terminating in a functional group capable of covalently linking to a terminal hydroxyl functionality group of the perfluorinated polyether.
13. The article of manufacture of claim 11 , wherein the fluoroelastomer (FE) group is a polymer comprising a monomer unit selected from the group consisting of vinylidene fluoride, tetrafluorethylene, hexafluoropropylene, perfluoromethylvinylether and combinations thereof.
14. The article of manufacture of claim 11 , wherein the fluoroelastomer (FE) group has a fluorine content of at least about 65 percent.
15. The article of manufacture of claim 11 , wherein the fluoroelastomer (FE) group has a molecular weight in a range from about 50,000 to about 70,0000 daltons as measured by gel permeation chromatography.
16. The article of manufacture of claim 11 , wherein the perfluorinated polyether (PFPE) is an alkoxysilane-terminated perfluorinated polyether having an average molecular weight in a range from about 1,500 daltons to about 2,500 daltons.
17. The article of manufacture of claim 11 , wherein the polymer coating has an hexadecane contact angle of at least about 50 degrees and a hexadecane slide angle of less than about 30 degrees, the polymer coating being thermally stable at 290° C. at 350 psi.
18. The article of manufacture of claim 11 , wherein the article of manufacture is an electronic device.
19. The article of manufacture of claim 11 , wherein the surface is selected from the group consisting of a glass surface, a metal surface, a plastic surface, a ceramic surface and a textile surface.
20. The article of manufacture of claim 11 , wherein the article of manufacture is a textile, a glass article, an automobile furnishing or a home appliance.