POLY(VINYL ALCOHOL) MODIFIED WITH CARBOXYLIC-ACID ANHYDRIDES - CROSS-LINKING THROUGH CARBOXYLIC GROUPS

The reaction of carboxylic acid anhydride with poly(vinyl alcohol) (PV A) leads to vinyl alcohol-vinyl ester copolymers which contain carboxy lic acid groups. Esterification enables degrees of modification to be reached which depend on the chemical structure of the anhydride introd uced and the ratio of the reagents in the feed. The copolymers obtaine d were characterized by spectroscopic techniques, elemental analysis, and thermal methods. These half-esters reacted in a second step with a romatic diglycidyl ethers to obtain tridimensional networks. This cros slinking reaction through the carboxylic groups was studied by differe ntial scanning calorimetry. The water absorption of the linear and cro sslinked. polymers was determined gravimetrically as a function of tim e at room temperature. (C) 1997 John Wiley & Sons, Inc.