Ionic liquids as flame-retardant synergists for polyamide polymers

A flame retardant or flame resistant material comprising a base material, a non-halogenated flame retardant component, and an ionic liquid flame retardant component, wherein the ionic liquid flame retardant component comprises a compound having formula (I):

• wherein A is P and
• each of R1, R2, R3 and R4 is independently selected from the group consisting of (C1-C20)alkyl, aryl, (C3-C10)heterocyclyl, (C3-C10)cycloalkyl, (C3-C10)heterocyclyl(C1-C8) alkyl, aryl(C1-C8)alkyl, heteroaryl and heteroaryl(C1-C8)alkyl that may be unsubstituted or substituted by halogen, nitro, trifluoromethyl, trifluoromethoxy, methoxy, carboxy, —NH2, —OH, —SH, —NHCH3, —N(CH3)2, cyano, —SMe, and —SO3H,
• X− is selected from the group consisting of halide, [B(R)4]−, OH−, SCN−, RPO4−, (RO)2P(═O)O−, RSO4−, RSO3−;
• ROSO3−, [N(CN)2]−, [RCOO]−, [NO3]−, [PF6]−, [BF4]−, (RSO2)2N−, oxalate, dicarboxylate and tricarboxylate, formate, phosphate, and aluminate, wherein each R is independently selected from the group consisting of (C1-C20)alkyl, aryl, (C3-C10)heterocyclyl, (C3-C10)cycloalkyl, (C3-C10)heterocyclyl(C1-C8)alkyl, aryl(C1-C8)alkyl, heteroaryl and heteroaryl(C1-C8)alkyl group that may be unsubstituted or substituted by halogen, nitro, methoxy, carboxy, —NH2, —OH, —SH, —NHCH3, —N(CH3)2, —SMe and cyano.