A method for the preparation of polyimides or their biologically degrading peasants polypeptidic hydrolysates

摘要

Process for the preparation of polyimides or of their polypeptide hydrolysates with a biodegradability of at least 80%, by thermal polycondensation of at least one amino acid and then, optionally, hydrolysis, the thermal polycondensation stage being carried out in the presence of at least one "acid catalyst" chosen from . sulphuric, nitric, phosphorous, sulphurous, hydrofluoric, silicic and sulfonic acids, organic sulfonic acids containing less than 50 carbon atoms, amino acids carrying a strong acid functional group which is not a carboxylic acid functional group, organic phosphonic acids and organic carboxylic acids having a pKa less than or equal to 5 and preferably less than or equal to 3; . precursors of these acids; . salts of these acids and of an amino acid which is the same as or different from that or those used; . salts of these acids and of a polyimide derived from the polycondensation of at least one amino acid which is the same as or different from that or those used; . hydrochloric acid and its precursors; . salts of hydrochloric acid and of an amino acid which is the same as or different from that or those used, when the amino acid to be polycondensed is other than glutamic acid; . salts of hydrochloric acid and of a polyimide derived from the polycondensation of at least one amino acid which is the same as or different from that or those used; . acid salts of sulphuric, phosphoric or phosphorous acids or their precursors; . precursors of phosphoric acid other than phosphorus pentoxide or polyphosphoric acids; . and Lewis acids; according to an "acid catalyst"/amino acid molar ratio of at least 0.001. Use of the polyimides or of the polypeptide hydrolysates thus obtained in detergent compositions, and detergent compositions containing the said polyimides or hydrolysates.