Abstract To achieve efficient utilization of compression wood (CW), a deeper insight into the molecular interactions is necessary. In particular, the role of lignin in the wood needs to be better understood, especially concerning how lignin contributes to its mechanical properties. For this reason, the properties of CW and normal wood (NW) from Chinese fir (Cunninghamia lanceolata) have been studied on a molecular scale by means of polarized Fourier transform infrared (FTIR) spectroscopy, under both static and dynamic loading conditions. Under static tensile loading, only molecular deformations of cellulose were observed in both CW and NW. No participation of lignin could be detected. In relation to the macroscopic strain, the molecular deformation of the cellulose C-O-C bond was greater in NW than in CW as a reflection of the higher microfibril angle and the lower load taken up by CW. Under dynamic deformation, a larger contribution of the lignin to stress transfer was detected in CW; the molecular deformation of the lignin being highly related to the amplitude of the applied stress. Correlation analysis indicated that there was a direct coupling between lignin and cellulose in CW, but there was no evidence of such a direct coupling in NW.

中文翻译：

---

通过拉伸 FTIR 载荷观察木质素对压缩木材应力传递的贡献

摘要 为了实现压缩木材 (CW) 的有效利用，需要更深入地了解分子间的相互作用。尤其需要更好地了解木质素在木材中的作用，尤其是木质素如何影响其机械性能。因此，在静态和动态负载条件下，通过偏振傅里叶变换红外 (FTIR) 光谱在分子尺度上研究了来自杉木 (Cunninghamia lanceolata) 的 CW 和普通木材 (NW) 的特性。在静态拉伸载荷下，在 CW 和 NW 中仅观察到纤维素的分子变形。没有检测到木质素的参与。关于宏观应变，纤维素 COC 键的分子变形在 NW 中比在 CW 中更大，这反映了更高的微纤丝角度和 CW 所承受的较低负载。在动态变形下，在 CW 中检测到木质素对应力传递的更大贡献；木质素的分子变形与施加的应力幅度高度相关。相关性分析表明，在 CW 中木质素和纤维素之间存在直接耦合，但在 NW 中没有这种直接耦合的证据。