XRD investigation of mechanical properties of cellulose microfibrils in S1 and S3 layers of thermally modified wood under tensile loading
XRD investigation of mechanical properties of cellulose microfibrils in S1 and S3 layers of thermally modified wood under tensile loading
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DOI：
10.1007/s00226-021-01263-z
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发表时间：
2021-05-16
影响因子：
3.4
通讯作者：
Sasaki, Yasutoshi
中科院分区：
文献类型：
--
作者：
Kojima, Erina;Yamasaki, Mariko;Sasaki, Yasutoshi
本研究考察了热改性对软木细胞壁力学性能的影响，以阐明微观行为(纤维素微纤维)和宏观行为(散装木材)之间的关系。在两种不同的温度下对试件进行了三个阶段的热改性。然后，对热改性原木进行了轴向拉伸载荷下的同步辐射X射线衍射仪测试。同时得到了S1层和S3层的纤维素晶格应变和散装木材的应变。拉伸试验的结果是，对于未改性的试件，S1和S3层中的纤维素微纤维的载荷-应变关系表现出与散装木材相似的线性行为。相反，对于热改性试件，发现S1和S3层中纤维素微纤维的载荷-应变关系不是线性的。热改性对原木拉伸性能的影响不同于S1层和S3层的纤维微纤化。此外，与S2层的纤维微纤化结果相比，不同细胞壁层的热改性效果不同。其原因与纤维的取向角和线性度有关。
This research examines the effect of thermal modification on the mechanical properties of the soft wood cell wall in order to clarify the relationship between the micro-level behavior (cellulose microfibrils) and macro-level behavior (bulk wood). The thermal modification of three stages at two different temperatures was conducted on the specimens. Then, the synchrotron radiation XRD under tensile loading in the axial direction of thermally modified bulk wood was performed. Simultaneously, the lattice strain of cellulose in the S1 and S3 layers and the strain of bulk wood were obtained. As a result of the tensile test, for unmodified specimens, the load-strain relationship of the cellulose microfibrils in the S1 and S3 layers showed linear behavior similar to bulk wood. In contrast, for thermally modified specimens, it was found that the load-strain relationship of the cellulose microfibrils in the S1 and S3 layers was not linear. The effects of thermal modification on tensile properties of bulk wood differed from that of the cellulose microfibrils in the S1 and S3 layers. Furthermore, when compared with the results of the cellulose microfibrils in the S2 layer, the effect of thermal modification was different between the cell wall layers. The reason for this was suggested by the orientation angle and linearity of the cellulose microfibrils.