GB898651A - Polymers containing polyamide-acid recurring units and their production - Google Patents

Abstract

Polyamide-acids having the recurring unit:- <FORM:0898651/IV (a)/1> or <FORM:0898651/IV (a)/2> where R is a tetravalent radical containing at least 2 carbon atoms, no more than 2 carbonyl groups of each polyamide-acid unit being attached to any one carbon atom of said tetravalent radical, R1 is a divalent radical containing at least 2 carbon atoms, the amide groups of adjacent polyamide-acid units each attached to separate carbon atoms of said divalent radical, said polyamide-acid having an inherent viscosity measured at 30 DEG C. at a concentration of 0,5% by weight of the polymer are made by reacting at least one diamine of the formula H2N-R1-NH2 with at least one tetracarboxylic acid dianhydride having the structural formula <FORM:0898651/IV (a)/3> in an organic solvent for the product and at least one of the reactants whose functional groups do not react with either of the reactants to a greater extent than the reactants do with each other, under substantially anhydrous conditions at a temperature below 60 DEG C. The polyamide-acid may be separated from the reaction mixture by precipitating in a non-solvent such as cyclohexane, dioxane or benzene. Many diamines are specified, examples being m-phenylene diamine, p-phenylene diamine, benzidine, hexamethylene diamine, 3-methoxyhexamethylene diamine, 2:11-diaminododecane and piperazine. Specified tetracarboxylic acid dianhydrides are pyromellitic, 2,3,6,7-naphthalene tetracarboxylic, 3,31,4,41-diphenyl tetracarboxylic, 1,2,5,6-naphthalene tetracarboxylic, 2,21,3,31-diphenyl tetracarboxylic, 2,2-bis(3,4-dicarboxyphenyl)propane, 3,4-dicarboxyphenyl sulphone, perylene 3,4,9,10-tetracarboxylic, bis(3,4-dicarboxyphenyl) ether and ethylene tetracarboxylic dianhydride. Specified solvents are N,N-dimethyl formamide, N, N-dimethyl acetamide, N,N-diethyl formamide, N,N-diethylacetamide, N,N-dimethyl methoxy acetamide, N-methyl caprolactam, dimethyl sulphoxide, N-methyl-2-pyrrolidone, tetramethylene urea, pyridine, dimethyl sulphone, hexamethyl phosphoramide, tetramethylene sulphone, formamide, N-methyl formamide and N-acetyl-2-pyrrolidone alone or in combination with benzene, benzonitrile, dioxane, butyrolactone, xylene, toluene and cyclohexane. In the Examples:- (1), (7), (11) to (13), (22) and (23) m-phenylene diamine; (2) p-phenylene diamine; (3) and (14) benzidine; (4) m-phenylene diamine, p-phenylene diamine and benzidine; (5) 2,2-bis(4-aminophenyl)propane; (6) m-phenylene diamine and bis(4-aminophenyl)methane; (8) bis(4-aminophenyl) methane; (9) m-phenylene diamine and hexamethylene diamine; (10) 4,41-diaminodiphenyl methane and hexamethylene diamine; (15) m-xylylene diamine; (16) 2:11-dodecane diamine; (17) hexamethylene diamine; (18) 4,4-dimethylheptamethylene diamine; (19) and (20) bis(p-aminophenyl) ether; (21) 4,41-diaminodiphenyl methane; (24) diaminodiphenyl sulphide; (25) bis(4-aminophenyl) sulphone and 26) 4,41-diaminodiphenyl ether are reacted with:- (1) to (11), (15) to (19) and (21) to (26) pyromellitic dianhydride; (12) pyromellitic dianhydride and phthalic anhydride; (13), (14) and (25) 2,2-bis(dicarboxyphenyl) propane in the presence of:- (1), (2), (12) to (16), (19) and (26) N:N-dimethyl acetamide; (3) to (11), (17), (18), (21), (22) and (25) N:N-dimethyl formamide (20) pyridine; (23) dimethyl sulphoxide and (24) pyridine and dimethyl formamide.