The oxidative and non-oxidative degradation behaviour of a flexible polyurethane foam, synthesised from toluene diisocyanate and a polyether polyol, is reported. Both toluene diisocyanate and diaminotoluene were identified as major products under non-oxidative conditions, which indicates that the urethane linkages are degrading by two competing degradation mechanisms. Degradation of the urethane linkage by a depolymerisation reaction to yield toluene diisocyanate and polyol is proposed to occur initially. In addition, the atmospheric pressure conditions favour the degradation of the urethane linkages via a six-membered ring transition state reaction to form diaminotoluene, carbon dioxide and alkene terminated polyol chains. Solid-state ¹³C NMR spectroscopy and elemental analysis of the residues indicates that at temperatures above 300 °C ring fusion of the aromatic components within the foam occurs, and this leads to a nitrogen-containing carbonaceous char which has a complex aromatic structure. It is proposed that under the confined conditions of the degradation the aromatic nitrogen-containing species, such as toluene diisocyanate and diaminotoluene, undergo secondary reactions and ring fusion to yield a complex char structure.

Under oxidative conditions, degradation, including ring fusion, occurs at a lower temperature than under non-oxidative conditions. Neither toluene diisocyanate nor diaminotoluene were observed as major degradation products. The polyol is observed to undergo thermo-oxidative degradation at much lower temperatures than purely thermal degradation. As a consequence, the depolymerisation reaction via the six-membered ring transition state is limited in extent and diaminotoluene is not evolved. The absence of toluene diisocyanate is proposed to be a result of this species undergoing oxidative degradation reactions which lead to it being incorporated into the char.

据报道，由甲苯二异氰酸酯和聚醚多元醇合成的软质聚氨酯泡沫的氧化和非氧化降解行为。在非氧化条件下，甲苯二异氰酸酯和二氨基甲苯均被鉴定为主要产物，这表明氨基甲酸酯键正在通过两种竞争性降解机理降解。最初建议通过解聚反应使氨基甲酸酯键降解以产生甲苯二异氰酸酯和多元醇。另外，大气压条件有利于经由六元环过渡态反应的氨基甲酸酯键的降解，以形成二氨基甲苯，二氧化碳和烯烃封端的多元醇链。固态¹³残留物的13 C NMR光谱和元素分析表明，在高于300°C的温度下，泡沫内的芳族组分发生环熔化，这导致形成具有复杂芳族结构的含氮碳质炭。提出在降解的限制条件下，含芳族氮的物质，例如甲苯二异氰酸酯和二氨基甲苯，经历二次反应和环稠合以产生复杂的炭结构。

在氧化条件下，包括环稠合在内的降解在比非氧化条件下更低的温度下发生。没有观察到甲苯二异氰酸酯和二氨基甲苯是主要的降解产物。观察到多元醇在比纯热降解低得多的温度下发生热氧化降解。结果，经由六元环过渡态的解聚反应在一定程度上受到限制，并且不释放出二氨基甲苯。提议不存在甲苯二异氰酸酯是由于该物种经历了氧化降解反应，导致其被引入炭中。