Abstract The thermal degradation of hides before and after tanning with formaldehyde and glutaraldehyde were studied using thermogravimetric analyzer (TGA) and TGA coupled with Fourier transform infrared spectrometry (TGA-FTIR). TG-FTIR analysis indicated that the pyrolysis products of both untanned hides and tanned leathers are mainly CO2, NH3, and C = O with some HNCO, CH4 and H2O. Compared to that of untanned hides, the peak intensity of evolved NH3 from formaldehyde tanned one is enhanced, while the evolved temperature decreases from 220 °C to 200 °C. The evolution of C = O is increased due to the introduction of carbonyl groups after formaldehyde tanning. However, for the glutaraldehyde-tanned leather, the evolution peak intensity of C = O decreases with more CO2 yield, suggesting that the carbonyl groups introduced by glutaraldehyde-tanning is mainly changed to CO2 rather than C = O. The kinetic analysis of thermal degradation process of the hides and tanned leathers are also investigated by using the methods of Flynn-Wall-Ozawa, Friedman and Criado. Results indicated that the thermal degradation process can be described by the three-dimensional diffusion model (D3) at the conversion below 0.5. Whereas, at the conversion above 0.5, this process turns to comply random nucleation model (F3).

中文翻译：

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醛鞣革热降解动力学及机理

摘要 采用热重分析仪(TGA)和TGA-傅里叶变换红外光谱法(TGA-FTIR)研究了甲醛和戊二醛鞣制前后生皮的热降解情况。TG-FTIR 分析表明，未鞣革和鞣革的热解产物主要是 CO2、NH3 和 C=O，还有一些 HNCO、CH4 和 H2O。与未经鞣制的生皮相比，甲醛鞣制的生皮放出 NH3 的峰值强度有所增强，而放出温度从 220 °C 降低到 200 °C。由于甲醛鞣制后引入羰基，C = O 的演变增加。然而，对于戊二醛鞣革，C = O 的演化峰强度随着 CO2 产量的增加而降低，表明戊二醛鞣制引入的羰基主要转变为 CO2 而不是 C=O。还利用 Flynn-Wall-Ozawa、Friedman 和克里亚多。结果表明，热降解过程可以用三维扩散模型（D3）在0.5以下的转化率下描述。而当转换率高于 0.5 时，该过程变为符合随机成核模型 (F3)。结果表明，热降解过程可以用三维扩散模型（D3）在0.5以下的转化率下描述。而当转换率高于 0.5 时，该过程变为符合随机成核模型 (F3)。结果表明，热降解过程可以用三维扩散模型（D3）在0.5以下的转化率下描述。而当转换率高于 0.5 时，该过程变为符合随机成核模型 (F3)。