摘要:
High molecular weight linear condensation polyesters are stabilized against deterioration by heat by reacting the polyester in molten form with alkylene carbonates in the presence of a catalytic amount of a compound selected from the group consisting of sodium iodide and potassium iodide.
摘要:
Described herein is a process for preparing polyarylates which comprises reacting a diester derivative of a dihydric phenol with an aromatic dicarboxylic acid in the presence of from about 10 to about 60 weight percent of a diphenyl ether compound at a temperature of from about 260.degree. to about 350.degree. C. and in the presence of a magnesium catalyst.
摘要:
An improved acid interchange polymerization process for the formation of an aromatic polyester is provided. Ester and carboxylic acid functional groups are reacted in the presence of a catalytically effective amount of a catalyst consisting of a mixture of a transition metal salt of a strong inorganic acid and a transition metal salt of an aliphatic carboxylic acid containing up to about 4 carbon atoms. In a preferred embodiment of the process the reactants are at least one aromatic diester and at least one aromatic dicarboxylic acid. Alternatively, the ester and carboxylic acid functional groups required for the acid interchange reaction may be provided upon the same molecule. Halogen or other substituent groups which do not interfere with the acid interchange reaction optionally may be present upon the aromatic rings.