Method for the production of thermoplastic polyoxazolidinone polymers

A process for producing a thermoplastic polyoxazolidinone comprising copolymerization of

• a diisocyanate compound with a bisepoxide compound in the presence of components comprising a catalyst, a chain regulator comprising a monofunctional epoxide, a monofunctional isocyanate, or a mixture thereof, and a solvent composition comprising a polar aprotic solvent, wherein
• the catalyst comprises an alkali halogenide, an earth alkali halogenide, or a transition metal halogenide, and wherein
• the process comprises:
• (a) placing the polar aprotic solvent and the catalyst in a reactor to provide a mixture,
• (b) adding the diisocyanate compound, the bisepoxide compound and the chain regulator to the mixture resulting from step (a) to form a thermoplastic polyoxazolidinone, and
• (c) reacting the thermoplastic polyoxazolidinone with an alkylene oxide,
• wherein a calculated weight ratio of the sum of the weight of diisocyanate compound, bisepoxide compound, and chain regulator used to the sum of the weight of diisocyanate compound, bisepoxide compound, chain regulator, and polar aprotic solvent used in step (a) is from 5 wt % to 26 wt %,
• wherein steps (a) and (b) are performed at a reaction temperature of ≥130° C. to ≤280° C. and a reaction time of 1 hour to 6 hours, and
• wherein the thermoplastic polyoxazolidinone has a number average molecular weight of ≥5,000 to ≤500,000 g/mol as determined with gel permeation chromatography (GPC).