Multi-branched mannich base corrosion inhibitor and preparation method thereof

A multi-branched Mannich base corrosion inhibitor, characterized by the structure of:

• wherein
• N1, Nx, Ny, Nm, and Nn are nitrogen atoms on C—N skeleton, x, y, m and n are sequence numbers thereof, and 2≦x≦m≦y≦n−1, and 3≦n≦7;
• R1, Rm and Rn are substituents in starting material ketone after the substitution of active hydrogen on the carbon atom linked to carbonyl, and are aliphatic ketone group, alicyclic ketone group and aromatic ketone group, respectively;
• the ketone group within the ring of the alicyclic ketone groups is selected from the group consisting of cyclohexanone group, cyclopentanone group, o-methyl cyclohexanone group, p-methyl cyclohexanone group, 2-methyl cyclopentanone group, 2-ethyl cyclopentanone group, 3-ethyl cyclopentanone group, and the aliphatic ketone group, aromatic ketone group and other alicyclic ketone group are represented by the following formula:
• wherein Ra and Rb each independently represents C1-C6 alkyl, C6-C9 linear or branched aryl, C5-C9 linear or branched cycloalkyl group;
• Rx and Ry are H or
• Rx and Ry are H or
• R′ is substituent in starting material ketone after the substitution of active hydrogen on the carbon atom linked to carbonyl, and is aliphatic ketone group, alicyclic ketone group and aromatic ketone group, respectively;
• the ketone group within the ring of the alicyclic ketone group is selected from the group consisting of cyclohexanone group, cyclopentanone group, o-methyl cyclohexanone group, p-methyl cyclohexanone group, 2-methyl cyclopentanone group, 2-ethyl cyclopentanone group, 3-ethyl cyclopentanone group, and the aliphatic ketone group, aromatic ketone group and other alicyclic ketone group are represented by the following formula:
• wherein Ra and Rb each independently represents C1-C6 alkyl, C6-C9 linear or branched aryl, C5-C9 linear or branched cycloalkyl group.