Method for preparing polymethylene polyphenyl polycarbamate

摘要

A method for preparing polymethylene polyphenyl polycarbamate is provided. The method includes dissolving phenylcarbamate in a water-immiscible organic solvent to form a solution A, formulating an aqueous acid catalyst solution to form a solution B, forming a reaction system comprising an organic phase and an aqueous phase by firstly adding a methylating reagent to the solution B and then mixing the solution A and the solution B, wherein the organic phase comprises phenylcarbamate and the aqueous phase comprises the acid catalyst and the methylating reagent. The method further includes reacting the reaction system under stirring at a reaction temperature of 30° C. to 200° C. and a reaction pressure of 0.05 MPa to 5 MPa to produce a polymethylene polyphenyl polycarbamate product mixture dissolved in the organic phase, and separating the polymethylene polyphenyl polycarbamate product mixture by allowing the organic phase and the aqueous phase to stand still and stratify.

主权项

1. A method for preparing polymethylene polyphenyl polycarbamate that is carried out through a condensation of phenylcarbamate with a methylating reagent under a catalyzation of a phase transfer acid catalyst, comprising the steps of:
a) dissolving phenylcarbamate in a water-immiscible organic solvent to form a solution A; b) formulating an aqueous acid catalyst solution to form a solution B; c) forming a reaction system comprising an organic phase and an aqueous phase by firstly adding a methylating reagent to the solution B and then mixing the solution A and the solution B, or by adding the methylating reagent at the same time of mixing the solution A and the solution B or after mixing the solution A and the solution B, wherein the organic phase comprises phenylcarbamate and the aqueous phase comprises the phase transfer acid catalyst and the methylating reagent; d) reacting the reaction system under stirring at a reaction temperature of about 30° C. to about 200° C. and a reaction pressure of about 0.05 MPa to about 5 MPa to produce a polymethylene polyphenyl polycarbamate product mixture dissolved in the organic phase; and e) separating the polymethylene polyphenyl polycarbamate product mixture by allowing the organic phase and the aqueous phase to stand still and stratify.