Fluoroelastomer composition

A fluoroelastomer composition [composition (C)] comprising:

• at least one vinylidene-fluoride based fluoroelastomer comprising recurring units derived from vinylidene fluoride (VDF) and from at least one additional (per)fluorinated monomer different from VDF [fluoroelastomer (A)];
• at least one basic compound [base (B)];
• at least one pyridinium salt [salt (P)] complying with any of formulae (P-1) to (P-12):
• wherein:
• each of J and J′, equal to or different from each other, is independently at each occurrence C—R* or N, wherein R* is H or a C1-C12 hydrocarbon group;
• E is N or a group of formula C—RoH;
• Z is a divalent hydrocarbon group comprising from 1 to 12 carbon atoms;
• W is a bond or is a bridging group selected from the group consisting of divalent hydrocarbon groups comprising from 1 to 12 carbon atoms and divalent fluorocarbon groups comprising from 1 to 12 carbon atoms;
• the group sketched with symbol:
• in formula (P-11) and (P-12) designates an aromatic mono- or poly-nuclear ring condensed to the pyridinium-type aromatic ring, which may comprise one or more additional nitrogen atoms, optionally quaternized nitrogen atoms, in the ring(s);
• each of R1H, R2H, R3H, R4H, R5H, R6H, R7H, R8H, R9H, R10H, R11H, R12H, R13H, R14H, R15H, R16H, R17H, R18H, R19H, R20H, R21H, R22H, R23H, R24H, R25H, R26H, R27H, R28H, R29H, R30H, R31H, R32H, R33H, R34H, R35H, R36H and RoH, equal to or different from each other, is independently at each occurrence —H or a group of formula [group (alpha-H)]:
• wherein Ra, and Rb, equal to or different from each other, are independently H or a hydrocarbon C1-C6 group;
• Y, equal to or different from each other, is independently oxygen or a C1-C12 hydrocarbon group, optionally comprising one or more than one heteroatoms selected from N, O, S and halogens;
• A(m−) is an anion having valency m;
• with the provisio that
• (i) when salt (P) is of formula (P-1) at least two of R1H, R2H, and RoH are groups (alpha-H);
• (ii) when salt (P) is of formula (P-2) R3H and R4H are groups (alpha-H);
• (iii) when salt (P) is of formula (P-3), at least two of R5H, R6H, R7H, and R8H are groups (alpha-H);
• (iv) when salt (P) is of formula (P-4), at least two of R9H, R10H, R11H, R12H, and RoH are groups (alpha-H);
• (v) when salt (P) is of formula (P-5), at least two of R13H, R14H, and RoH are groups (alpha-H);
• (vi) when salt (P) is of formula (P-6), at least two of R15H, R16H, R17H, and RoH are groups (alpha-H);
• (vii) when salt (P) is of formula (P-7), at least two of R18H, R19H, R20H, R21H, and RoH are groups (alpha-H);
• (viii) when salt (P) is of formula (P-8), at least two of R22H, R23H, R24H, and RoH are groups (alpha-H);
• (ix) when salt (P) is of formula (P-9), at least two of R25H, R26H, R27H, and R28H are groups (alpha-H);
• (x) when salt (P) is of formula (P-10), at least two of R29H, R30H, R31H, R32H, and R28H are groups (alpha-H);
• (xi) when salt (P) is of formula (P-11), at least two of R33H, R34H, and R28H are groups (alpha-H);
• and
• (xii) when salt (P) is of formula (P-12), at least two of R35H, R36H and RoH are groups (alpha-H).