Exploring the mechanical roles of lignin and hemicellulose from the viewpoint of wood processing

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15570
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40020:Wood science-related
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Miyoshi Yuka 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (50781598)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 熱軟化特性 / リグニン / ヘミセルロース

Outline of Final Research Achievements

In this study, the relationship between thermal-softening properties and lignin structure of various wood species, and changes in mechanical properties of wood specimens with selective removal of lignin and hemicellulose were examined to obtain a basic knowledge for controlling the processability of wood.
It was found that the thermal-softening properties of various wood species differed between softwoods and hardwoods, and that the thermal-softening temperatures roughly corresponded to the syringyl ratio of the lignin. The results of dynamic viscoelasticity and creep tests of the delignified or hemicellulose-extracted wood indicated that the increase in fluidity was due to a decrease in the interaction between lignin and hemicellulose as well as structural changes in the lignin.

Free Research Field

木材物理

Academic Significance and Societal Importance of the Research Achievements

科・属・種、組織構造、産地等が異なる約80個体の木材標本について抽出処理前後の熱軟化特性を測定し、学術的に資料性の高いデータを詳細にそろえることができた。また、これまで根拠の乏しかった熱軟化温度とリグニン構造の関係について、リグニンのシリンギル核比を用いて検証を行い、両者の関係性を示す結果を新たに得ることができた。さらに、リグニンとヘミセルロースの除去が変形特性へ及ぼす影響についても明らかにできた。以上の結果は、木材の加工性を効率的かつ高度に制御するための基礎として技術に応用できるものであり、社会的意義がある。