Degradation of polyesteramides during composting under standard and isothermal conditions

Polyesteramides based on ɛ-caprolactam and ɛ-caprolactone differing in the content of ester-amide structural units were subjected to biodegradation — composting in a big compost pile under controlled conditions (controlled composting) and in small composters at a steady temperature of 60 °C (isothermal composting). Both types of composting resulted in degradation of the polyesteramides depending on copolymer composition, isothermal composting being more robust. The contribution of abiotic hydrolysis to the degradation of polyesteramides was studied at 60 °C in buffer solutions with pH 5.4, 7.4 and 8.4. The prevailing effect of abiotic hydrolysis over biological one was shown at 60 °C. Ester bonds in polyestramide chains were preferentially cleaved; therefore, the scope of degradation increased with the content of ester units in the copolymer.