Methods for synthesizing polyvinyl amine (PVA) type flocculating and coagulating agents, novel agents thus obtained, uses thereof and improved paper types thus obtained

摘要

The invention relates to a process of synthesis at low temperature of polymers of the PVA (polyvinylamine) type on the basis the monomer vinylformamide. The polymerization claimed for the invention begins at around 0° C., is initiated by an original combination of redox and azoic catalysts, and is conducted under more or less normal pressure. The polymerization is conducted in water and is followed by direct hydrolysis. A powdered cationic PVA of high molecular weight is thereby obtained. The process may also be conducted in an emulsion at an initiation temperature of around 15° C. Application of PVAs as flocculants and coagulants in the paper, water treatment, petroleum and parapetroleum, and, similar industries.