Fluorinated elastomers cured by actinic radiation and methods thereof
Described herein is a curable composition comprising an amorphous fluoropolymer having an iodine, bromine and/or nitrile cure site; a peroxide cure system comprising a peroxide and a Type II coagent; and a photoinitiator, wherein the curable composition is substantially free of a binder material. Also described herein, are methods of curing the curable composition using actinic radiation and articles thereof.
1. A curable composition comprising:
(a) an amorphous fluoropolymer having an iodine, bromine and/or nitrile cure site;
(b) a peroxide cure system comprising a peroxide and a Type II coagent; and
(c) a photoinitiator,
wherein the curable composition is substantially free of a binder material.
2. The curable composition of claim 1 , wherein the curable composition is substantially free of an unsaturated metal coagent.
3. The curable composition of claim 1 , wherein the amorphous fluoropolymer is partially fluorinated.
4. The curable composition of claim 1 , wherein the absorbance profile of the peroxide does not substantially interfere with the absorbance profile of the photoinitiator.
5. The curable composition of claim 1 , wherein the peroxide cure system consists essentially of a peroxide and a Type II coagent.
6. The curable composition of claim 1 , wherein curable composition is substantially free of polymerizable acrylate, polymerizable methacrylate, or combinations thereof.
7. The curable composition of claim 1 , wherein the binder material has a molecular weight of less than 5,000 g/mol.
8. The curable composition of claim 1 , wherein the photoinitator is at least one of 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, phenyl bis(2,4,6-trimethyl benzoyl) phosphine oxide, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, and bis (eta 5-2,4-cyclopentadien-1-yl) bis [2,6-difluoro-3-(1H-pyrrol-1-yl) phenyl]titanium.
9. The curable composition of claim 1 , wherein the photoinitator comprises a photosensitizer, and at least one of an iodonium salt or an electron donor.
10. A cured composition derived from the curable composition according to claim 1 .
11. A method of UV-curing a fluoroelastomer, the method comprising:
exposing the curable composition according to claim 1 to actinic radiation.
12. A method of dual curing an amorphous fluoropolymer, the method comprising:
exposing the curable composition according to claim lto actinic radiation to form a partially cured composition; and
exposing the partially cured composition to a heat source wherein the peroxide is not benzoyl peroxide.
13. A method of making a shaped article, the method comprising:
exposing the composition of claim 1 to actinic radiation to partially cure the composition to form a shaped article; and
exposing the shaped article to heat source to further cure the shaped article.
14. A method of producing a fluoropolymer article comprising subjecting the curable composition according to claim 1 to additive processing in an additive processing device containing at least one actinic radiation source.
15. A curable composition consisting essentially of:
an amorphous fluoropolymer having an iodine, bromine and/or nitrile cure site;
a peroxide cure system comprising a peroxide and a Type II coagent;
a photoinitiator, and
optionally, an additive selected from the group consisting of an inorganic filler, a carbon particle, a high temperature plastic, or an acid acceptor.
16. The curable composition of claim 1 , wherein the amorphous fluoropolymer comprises at least one of a carbon-carbon double bond, or a unit capable of forming carbon-carbon double bonds along the amorphous fluoropolymer chain.
17. The curable composition of claim 1 , wherein the amorphous fluoropolymer comprises at least 0.1 wt % of an iodine, bromine and/or nitrile cure site.
18. The curable composition of claim 1 , wherein the amorphous fluoropolymer is a copolymer of (i) hexafluoropropylene, tetrafluoroethylene, and vinylidene fluoride; (ii) hexafluoropropylene and vinylidene fluoride, (iii) vinylidene fluoride and perfluoromethyl vinyl ether, (iv) vinylidene fluoride, tetrafluoroethylene, and perfluoromethyl vinyl ether, (v) vinylidene fluoride, tetrafluoroethylene, and propylene, or (vi) ethylene, tetrafluoroethylene, and perfluoromethyl vinyl ether, and (vii) blends thereof.
19. The curable composition of claim 1 , wherein the curable composition comprises at least 0.1 peroxide per 100 parts of the amorphous fluoropolymer.
20. The curable composition of claim 1 , wherein the Type II coagent comprises at least one of diallyl ether of glycerin, triallylphosphoric acid, diallyl adipate, diallylmelamine and triallyl isocyanurate, tri(methyl)allyl isocyanurate, tri(methyl)allyl cyanurate, poly-triallyl isocyanurate, and xylylene-bis(diallyl isocyanurate).