Determination method for viscosity average molecular weight of amphiphilic polymer

The invention discloses a method for determining the viscosity average molecular weight of an amphiphilic polymer. The method comprises the following steps: preparing a mixed solution of the amphiphilic polymer and NaCl; dividing the mixed solution into a plurality of parts, and then adding different amounts of beta-cyclodextrin into each part of the mixed solution, so that the concentrations of the beta-cyclodextrin in each part of the mixed solution are different; determining the intrinsic viscosity numbers of different polymers under different solvent conditions by referring to GB12005.1-89 and adopting an Ubbelohde viscometer; respectively calculating the intrinsic viscosity number of the amphiphilic polymer under the inclusion of the beta-cyclodextrin with different concentrations to obtain the viscosity average molecular weight of the target amphiphilic polymer. The beta-cyclodextrin can utilize the hydrophobic inner cavity of the beta-cyclodextrin to generate clathration with the hydrophobic side chain