A bonding agent includes: structural units represented by Formula I, Formula II, Formula III, and Formula IV: where each of R1, R2, R3, and R4 is independently selected from the group consisting of hydrogen, and C1-8 straight-chain or branched alkyl groups substituted or not substituted by a substituting group, each of R5, R6, and R7 is independently selected from the group consisting of hydrogen, and C1-6 straight-chain or branched alkyl groups substituted or not substituted by a substituting group, R8 is selected from C1-15 alkyl groups substituted or not substituted by a substituting group, each of R9, R10, and R11 is independently selected from the group consisting of hydrogen, and C1-6 straight-chain or branched alkyl groups substituted or not substituted by a substituting group.