Low-odor phosphazene catalyst and use thereof

A continuous preparation method for a low-odor phosphazene catalyst, comprising the following steps:

• (1) dissolving phosphorus pentahalide in an organic solvent to obtain an organic phosphorus pentahalide solution;
• adding dropwise a solution of guanidine compound to the organic phosphorus pentahalide solution under an inert atmosphere and at a temperature of −15° C.-5° C.;
• and
• bringing a temperature of the solution to room temperature after the addition is completed, stirring at the room temperature, then heating in an oil bath to facilitate continuous reaction, cooling to the room temperature upon completion of the reaction, filtering to remove a precipitate to obtain an organic phosphonium salt solution containing the organic solvent and a halogenated phosphorus compound;
• and
• (2) adding an alkali metal salt compound to the organic phosphonium salt solution obtained in the step (1);
• and
• performing the reaction under the inert atmosphere and heating conditions, cooling and filtering after the completion of the reaction, and distilling the filtrate under a reduced pressure to obtain a crude product of phosphazene compound,
• wherein the organic solvent is selected from at least one of nitriles or ethers,
• the alkali metal salt compound is selected from one of sodium alkoxide, potassium alkoxide, sodium carboxylate, potassium carboxylate, or phosphate metal salt, and
• the low-odor phosphazene catalyst comprises a phosphazene cation and an alkali metal salt compound anion represented by General Formula (I),
• in the above General Formula (I), X represents the alkali metal salt compound, and X-represents an alkali metal anion formed by a departure of a metal ion from X.