METHOD OF INCREASING MOLECULAR WEIGHT OF POLY (ARYL ETHERS)

摘要

"Method of Increasing Molecular Weight of Poly (Aryl Ethers)" A method of increasing the molecular weight of a poly (aryl ether) comprising providing a mixture of (1) at least one polyaryl ether comprising polymer chains having end groups selected from groups of formula -Ar-X, preferably -Y-Ar-X and -Ar-OX and (2) a reagent having nucleophilic activity selected -from a) alkaline salts of Group I or Group II metals (as hereinafter defined) and b) reagents have radicals -X and -OZ, reactive respectively with the end groups -Ar-OZ and -Ar-X, wherein when the end group is -Ar-X the reagent is either a difunctional reagent having either both end groups in the form of reactive -OZ groups or a difunctional reagent having one reactive -OZ group and one reactive -X group and when the end group is -Ar-OZ the reagent is a difunctional reagent having reactive end groups -X, and wherein Ar represents an arylene radical, preferably a phenylene radical, X is a monovalent radical capable of nucleophilic displacement from Ar, preferably selected from halogen, nitrile (CN) or nitro (NO2) radicals, Y is an electron withdrawing group, which when Ar is phenylene is positioned ortho or para, preferably para to the X group and when Ar is not phenylene, X and Y are attached to the Ar group by parallel and oppositely directed bonds and Z is a univalent metal, and heating the mixture to a temperature above the melting point of the polymer until a desired increase in molecular weight has occurred. The method is useful for preparing fibre reinforced compositions and particularly for the process of impregnating fibre structures.