The structural characteristics of crop straw (wheat straw, WS) lignin and softwood (pine wood, PW) lignin prepared using the enzymatic/mild acid hydrolysis method (EMAL) were deeply elucidated by FTIR (Fourier transform infrared), ¹³C-¹H 2D-NMR (nuclear magnetic resonance), and quantitative ³¹P-NMR combined with DFRC (derivatization followed by reductive cleavage). Then, the association of chemical structure and thermal degradation was evaluated by means of TG-FTIR-MS (thermo-gravimetric-FTIR-mass spectrometry) and Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry). The results showed that the functional groups and aromatic unit compositions of WS-EMAL were distinct from those of PW-EMAL, identifying the former as a HGS-lignin and the latter as a typical G-lignin. Both WS-EMAL and PW-EMAL were mainly cross-linked by β-O-4 linkages but had different contents. The amount of uncondensed β-O-4 linkages in WS-EMAL was 1168 μmol/g, which was lower than that in PW-EMAL (1297 μmol/g). These distinctions in structure caused a large difference in thermal stability, evolution behavior of typical volatiles and selectivities of G-, S-, H-, C-phenols between the two lignins. The mechanistic influence of structural features on pyrolysis behavior was intensively discussed, and a correlation between the two lignins was obtained.

通过FTIR（傅立叶变换红外），¹³ C- ¹ H对使用酶/温酸水解法（EMAL）制备的农作物秸秆（小麦秸秆，WS）木质素和软木（松木，PW）木质素的结构特征进行了阐明。2D-NMR（核磁共振），定量³¹P-NMR与DFRC结合（衍生化，然后还原裂解）。然后，通过TG-FTIR-MS（热重-FTIR-质谱）和Py-GC / MS（热解-气相色谱/质谱）评价化学结构与热降解的关系。结果表明，WS-EMAL的官能团和芳族单元组成与PW-EMAL有所不同，前者为HGS-木质素，后者为典型的G-木质素。WS-EMAL和PW-EMAL均主要通过β-O-4键交联，但含量不同。WS-EMAL中未缩合的β-O-4键数量为1168μmol/ g，低于PW-EMAL中的未缩合β-O-4键（1297μmol/ g）。这些结构上的差异导致了热稳定性，典型挥发物的析出行为以及G-，S-，H-，两个木质素之间的C-酚。深入讨论了结构特征对热解行为的机理影响，并获得了两种木质素之间的相关性。