Esterification of polymeric carboxylic acids

Polymers containing pendant carboxyl groups have been essentially completely esterified with little apparent change in molecular weight by the use of one of the following reagents: (1) trialkyl orthoesters, (2) dimethylformamide dialkyl acetals, (3) tertiary amines followed by alkyl halides, (4) quaternary ammonium hydroxide followed by alkyl halides. The use of some of these methods permits preparation of certain polymers that were previously not readily accessible.