THERMAL CATALYTIC DEPOLYMERIZATION OF POLYAMIDES

The formation of cyclic diamides of polyamides 4,6 and 6,6 by thermal catalytic depolymerization of the corresponding polyamides was investi gated. This method was optimized by changing external factors, like: c oncentration of catalyst; depolymerization temperature; - time; workin g under nitrogen flow and under a high vacuum (10(-5) mbar). The catal yst sodium-2-ethylhexanoate was used to accelerate the reaction. The d ifferent multi-component depolymerization products were analyzed by re versed phase HPLC. The formation of cyclic diamides of polyamides 4,6 and 6,6 was 10, respectively 20 wt.-%, under optimum conditions, which is not sufficient to be used as feed stock for new (co)polyamides.