Fluorinated block copolymers
Described herein is a millable fluorinated block copolymer having at least one A block and at least one B block, wherein the A block is a semi-crystalline segment comprising repeating divalent monomeric units derived from TFE, HFP and VDF; and the B block is a segment comprising repeating dilvalent monomeric units derived from HFP and VDF; and wherein the millable fluorinated block copolymer has a modulus of 0.1 to 2.5 MPa at 100° C.
1. A curable composition comprising:
a millable fluorinated block copolymer comprising at least one A block and at least one B block,
wherein the A block is a semi-crystalline segment comprising interpolymerized monomers,
wherein the monomers comprise TFE, HFP and VDF;
wherein the B block is a segment comprising interpolymerized monomers,
wherein the monomers comprise HFP and VDF; and
wherein the millable fluorinated block copolymer has a modulus of 0.1 to 2.5 MPa at 100° C.
2. The curable composition of claim 1 , wherein the fluorinated block copolymer has a melting point of at least 100 and at most 275° C.
3. The curable composition of claim 1 , wherein the B block is semi-crystalline.
4. The curable composition of claim 1 , wherein the B block is amorphous.
5. The curable composition of claim 1 , wherein the Tg of the A block is greater than 0° C. and less 80° C.
6. The curable composition of claim 1 , wherein the Tg of the B block is less than 0° C.
7. The curable composition of claim 1 , wherein the A block further comprises a monomer selected from the group consisting of a perfluorovinyl ether monomer, and a perfluoroallyl ether monomer.
8. The curable composition of claim 7 , wherein the perfluoroallyl ether monomer is selected from the group consisting of: perfluoro (methyl allyl) ether (CF 2 ═CF—CF 2 —O—CF 3 ), perfluoro (ethyl allyl) ether, perfluoro (n-propyl allyl) ether, perfluoro-2-propoxypropyl allyl ether, perfluoro-3-methoxy-n-propylallyl ether, perfluoro-2-methoxy-ethyl allyl ether, perfluoro-methoxy-methyl allyl ether, and CF 3 —(CF 2 ) 2 —O—CF(CF 3 )—CF 2 —O—CF(CF 3 )—CF 2 —O—CF 2 CF═CF 2 .
9. The curable composition of claim 1 , wherein the B block further comprises a monomer selected from the group consisting of TFE, a cure site monomer, a perfluorovinyl ether monomer, and a perfluoroallyl ether monomer.
10. The curable composition of claim 1 , wherein the millable fluorinated block copolymer comprises about 0.05 wt % to about 1 wt % of iodine based on the weight of the millable fluorinated block copolymer.
11. The curable composition of claim 1 , further comprising a peroxide cure system.
12. A cured article comprising a reaction product of components, wherein at least one of the components comprises the curable composition of claim 1 .
13. The cured article of claim 12 , wherein the article is a packer, an o-ring, a seal, a gasket, a hose, or a sheet.
14. The curable composition of claim 1 , wherein the glass transition temperature of the millable fluorinated block copolymer is less than −20° C.
15. The curable composition of claim 1 , wherein the A block comprises 30-85 wt % TFE; 5-40 wt % HFP; and 5-55 wt % VDF.
16. The curable composition of claim 15 , wherein the A block further comprises an additional monomer, wherein the additional monomer is less than 10% by weight of the A block.
17. The curable composition of claim 1 , wherein the B block comprises 25-65 wt % VDF and 15-60 wt % HFP.
18. The curable composition of claim 17 , wherein the B block further comprises an additional monomer, wherein the additional monomer is less than 20% by weight of the B block.
19. The curable composition of claim 1 , wherein the A block comprises 40-70 wt % TFE; 10-30 wt % HFP; and 10-45 wt % VDF.
20. The curable composition of claim 1 , wherein the B block comprises 35-60 wt % VDF and 25-50 wt % HFP.