Abstract: A synthesis method of ultra low molecular weight homopolymerized N-vinyl butyrolactam with ultra low residual monomer content is provided N-vinyl butyrolactam monomers and water are provided with the mass ratio of 3:17˜8:12 0.5%˜5.0% by weight of initiators, 0.1%˜5.0% by weight of a catalyst, and 0.1%˜10% by weight of a molecular weight regulator are provided in the presence of an inert gas, adding the above mentioned raw materials in batches, adjusting the pH of the reaction system to 7.0-8.0 with an activator, reacting at the polymerization temperature of 60-85° C. A peroxide is added and maintaining the temperature for 2 hours, to obtain an aqueous solution of ultra low molecular weight homopolymerized N-vinyl butyrolactam. The aqueous solution is dried to obtain a powdery ultra low molecular weight homopolymerized N-vinyl butyrolactam with ultra low residual monomer content.

Abstract: The present invention relates to a synthesis method of ultra low molecular weight homopolymerized N-vinyl butyrolactam with ultra low residual monomer content, which comprises: using N-vinyl butyrolactam monomers and water with the mass ratio of 3:17˜8:12, then based on the N-vinyl butyrolactam monomers, using 0.5%˜5.0% by weight of initiators, 0.1%˜5.0% by weight of a catalyst, and 0.1%˜10% by weight of a molecular weight regulator; in the presence of an inert gas, adding the above mentioned raw materials in batches, adjusting the pH of the reaction system to 7.0-8.0 with an activator, reacting at the polymerization temperature of 60-85° C.