Fuel composition and blend

A blend for use in a fuel comprising kerosene or a jet fuel comprising a cyclic compound comprising m units of the formula Ia

• an n units of the formula (Ib)
• joined together to form a ring,
• wherein Y is a divalent bridging group which may be the same or different in each unit;
• R0 is selected from the group consisting of H and (C1-C60) alkyl;
• and j is 1 or 2;
• R3 is selected from the group consisting of hydrogen, a hydrocarbyl and a hetero-substituted hydrocarbyl group;
• each of R1, R2 and R4 which may be the same and different, is selected from the group consisting of hydroxyl, hydrogen, hydrocarbyl and hetero-substituted hydrocarbyl, with the proviso that at least one of R1, R2 and R4 is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is at least 3, and a hydroxycarboxylic acid, different from said cyclic compound and with at least one chain of at least 8 carbons.

A method of thermally stabilizing a fuel which comprises a fuel selected from the group consisting of kerosene, a jet fuel and mixtures thereof, which comprises mixing with said fuel a cyclic compound comprising m units of the formula Ia

• an n units of the formula (Ib)
• joined together to form a ring,
• wherein Y is a divalent bridging group which may be the same or different in each unit;
• R0 is selected from the group consisting of H and (C1-C6) alkyl;
• R5 is selected from the group consisting of H and (C1-C60) alkyl;
• and j is 1 or 2;
• R3 is selected from the group consisting of hydrogen, a hydrocarbyl and a hetero-substituted hydrocarbyl group;
• each of R1, R2 and R4 which may be the same and different, is selected from the group consisting of hydroxyl, hydrogen, hydrocarbyl and hetero-substituted hydrocarbyl, with the proviso that at least one of R1, R2 and R4 is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is at least 3, and a hydroxycarboxylic acid, different from said cyclic compound and with at least one chain of at least 8 carbons.