Process for preparing hydrophilic-hydrophobic graft polymer with controllable main and side chain length

The present invention belongs to the field of grafted polymer preparing technology. The preparation process of hydrophilic-hydrophobic grafted polymer with controllable main and side chain length includes: atom transferring free radical polymerization to synthesize polystyrene and polyacrylate with hydrophobic macrochain and relative mass distribution not greater than 1.2; hydrolysis reaction in acid condition to obtain hydrophilic polymethacrylic acid or polyacrylic acid macrochain; nucleophilic substitution reaction between the halogen atom in the end of the hydrophobic macrochain and the side carboxyl group in the hydrophilic macrochain in solution to 'assemble' the hydrophobic macrochain to the hydrophilic macrochain to form the hydrophilic-hydrophobic grafted polymer; and regulating the ratio between the initiator and the monomer to control the macrochain length. Selecting different hydrophobic macrochain and hydrophilic macrochain can control the main and side chain length.