Heat stabilization of segmented copoly(ether ester)s

Abstract

Abstract Oxidative degradation of segmented copoly(ether ester)s can be suppressed by interference of the following basic processes: a. degradative radical chain reactions. Effective inhibition is possible by means of primary antioxidants. b. initiation of the radical chain reactions by means of hydroperoxides formed. Such initiation reactions can be suppressed by inactivation of the hydroperoxides with the aid of secondary antioxidants. c. polyester segmental chain scission by formic acid formed during oxidative degradation of the polyether segments. By scavenging the formic acid, or its precursor formaldehyde, this serious process can be restricted. Combined addition of stabilizers, simultaneously influencing the basic processes a., b. and c. can lead to synergism. Examples of the activity of the different stabilizers are given.