Fluoroelastomer composition

A (per)fluoroelastomer composition comprising:

• at least one (per)fluoroelastomer [fluoroelastomer (A)], said fluoroelastomer (A) comprising iodine and/or bromine atoms and having a backbone comprising:
• recurring units derived from tetrafluoroethylene (TFE);
• recurring units derived from at least one perfluorinated monomer selected from the group consisting of:
• PAVE monomers, wherein the PAVE monomers are perfluoroalkylvinylethers complying with formula CF2═CFORf1 in which Rf1 is a C1-C6 perfluoroalkyl;
• and
• MOVE monomers, wherein the MOVE monomers are perfluoro-oxyalkylvinylethers complying with formula CF2═CFOX0, in which X0 is (i) a C1-C12 perfluorooxyalkyl having one or more ether groups;
• or (ii) a group of formula -CF2ORf2 in which Rf2 is a C1-C6 perfluoroalkyl;
• optionally, recurring units derived from vinylidene fluoride (VDF) in an amount of up to 30% by moles, with respect to the total moles of recurring units;
• optionally, recurring units derived from at least one perfluorinated C3-C8 alpha- olefin, in an amount of up to 5% moles, with respect to the total moles of recurring units;
• optionally, recurring units derived from at least one fluorine-free alpha-olefin, in an amount of up to 10% moles, with respect to the total moles of recurring units;
• and
• optionally, recurring units derived from at least one bis-olefin [bis-olefin (OF)];
• from 0.5 to 5 weight parts, per 100 parts by weight of said fluoroelastomer (A), of at least one polyunsaturated compound selected from the group consisting of bis-olefins of formulae (OF-1), (OF-2) and (OF-3):
• wherein j is an integer between 2 and 10, and R1, R2, R3, R4, equal or different from each other, are H, F or C1-5 alkyl or (per)fluoroalkyl-group;
• wherein each of A, equal or different from each other and at each occurrence, is independently selected from F, Cl, and H;
• each of B, equal or different from each other and at each occurrence, is independently selected from F, Cl, H and ORB, wherein RB is a branched or straight chain alkyl radical which can be partially, substantially or completely fluorinated or chlorinated;
• E is a divalent group having 2 to 10 carbon atoms, optionally fluorinated, which may be inserted with ether linkages;
• wherein E, A and B have the same meaning as above defined;
• R5, R6, R7, equal or different from each other, are H, F or C1-5 alkyl or (per)fluoroalkyl group
• from 0.1 to 3 weight parts, per 100 parts by weight of said fluoroelastomer (A), of at least one organic peroxide;
• from 0.1 to 10 weight parts, per 100 parts by weight of said fluoroelastomer (A), of at least one organic compound [compound (C)] selected from the group consisting of:
• urea compounds of formula (U):
• wherein E is O, and each of Ru, equal to or different from each other, is independently selected from the group consisting of hydrogen and C1-C6 hydrocarbon groups;
• cyclic addition products of ammonia or primary amine and aldehyde;
• and
• carbamates of formula (C):
• wherein E is oxygen;
• Rb is a C1-C36 hydrocarbon group, and Re is H or a C1-C6 alkyl group.