Copolymer, treatment agent, and preparation method therefor and use thereof

A copolymer comprising a repeating unit derived from monomer I and a repeating unit derived from monomer II, wherein

• a) monomer I has the following general formula:
• CH2═C(R1)—X—Z
• wherein, X is selected from groups represented by X-1 and groups represented by X-2,
• —C(O)—O—(CH2)n- X-1
• —C(O)—N(R2)—(CH2)n- X-2
• R1 and R2 are selected from hydrogen atom or C1-C20 alkyl, n is an integer of 1-20;
• Z is selected from the following group:
• in group Z, R3, in each occurrence, is independently C1-C20 alkyl, C6-C20 aryl, C1-C20 alkoxy or a group R4—O—R5—, wherein R4 is C1-C10 alkyl, R5 is C1-C10 alkylene, and 1≤a≤200;
• Y1 and Y2, in each occurrence, are independently C1-C20 alkyl or C6-C20 aryl, or represented by the following group:
• R7, in each occurrence, is independently C1-C20 alkyl or C6-C20 aryl;
• R8, in each occurrence, is independently C1-C20 alkyl, C6-C20 aryl, C1-C20 alkoxy or a group R9—O—R10—, wherein R9 is C1-C10 alkyl, R10 is C1-C10 alkylene, and 0≤b≤200;
• b) monomer II has the following general formula:
• CH2═C(R1)—P—N(R3R4)
• wherein, P is selected from groups represented by P-1 and groups represented by P-2,
• —C(O)—O—(CH2)n- P-1
• —C(O)—N(R2)—(CH2)n- P-2
• wherein, R1 and R2 are selected from hydrogen atom or C1-C20 alkyl, n is an integer of 1-20;
• R3 and R4, in each occurrence, are independently C1-C8 alkyl or benzyl, or alternatively, R3 and R4 are jointed and, together with the nitrogen atom, form a morpholino, piperidino, or pyrrolidino group.