The present invention relates to a method that enables the production of a uniform polymer of high molar mass from cyclic imino ether monomer. This method comprises the following steps: a) providing a first liquid reaction mixture comprising cyclic imino ether monomer and optionally solvent； b) polymerizing cyclic imino ether monomer in the first reaction mixture by cationic ring opening polymerization to produce a polymerized first reaction mixture containing (i) polymerized material and (ii) solvent and/or unreacted cyclic imino ether monomer； c) separating solvent and/or unreacted cyclic imino ether monomer from polymerized material contained in the polymerized first reaction mixture； d) providing a second liquid reaction mixture containing cyclic imino ether monomer and solvent by combining the separated unreacted cyclic imino ether monomer and/or the separated solvent with other components； and e) polymerizing the cyclic imino ether monomer in the second reaction mixture by cationic ring opening polymerization. The invention also provides a polyoxazoline polymer comprising at least 50 wt.% of repeating units derived from a 2-substituted 2-oxazoline monomer selected from 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-n-propyl-2-oxazoline, 2-i-propyl-2-oxazoline and combinations thereof, said polymer having a DP of at least 250 and a very low dispersity.
