CARBOXYLIC ANHYDRIDE GROUPS AND CARBOXYLI C-ACID GROUPS IN POLYAMIDE MELTS .1. DEFINED DECOMPOSITION OF POLYAMIDE BY LOW-MOLECULAR AGENTS

In this first part of a review results are presented for the mechanism of the controlled decomposition of polyamides with carboxylic anhydri des and carboxylic acids as low molecular weight decomposition agents. Carboxylic acid groups show a surprisingly high reactivity under poly amide melt conditions compared with carboxylic anhydride groups. The d ecem position of polyamides by low molecular weight decomposition agen ts to controlled decomposed oligoamides with a narrow molecular weight distribution could be carried out in a twin screw extruder within a r esidence time lower than 5 min. The mechanism of decomposition will be discussed in comparison with published mechanisms from the literature .