Chemical changes of kenaf core binderless boards during hot pressing (I): influence of the pressing temperature condition
Chemical changes of kenaf core binderless boards during hot pressing (I): influence of the pressing temperature condition
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DOI：
10.1007/s10086-005-0761-4
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发表时间：
2006-06
影响因子：
2.9
通讯作者：
N. Okuda;K. Hori;Masatoshi Sato
中科院分区：
文献类型：
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作者：
N. Okuda;K. Hori;Masatoshi Sato
自胶合是无胶板材性能表现的主要因素，因此对其进行澄清被认为是一个重要的问题。为此，本文对红麻芯材无胶刨花板进行了一系列化学分析，探讨了热压过程中化学成分的变化。首先，以红麻芯粉为原料，在不同压制温度下（不采用汽爆工艺）制备无胶纸板，并将其粉碎后用甲醇提取，用于化学分析。为了研究它们的化学变化，测定木质素、综纤维素和中性糖含量，记录傅里叶变换红外（FTIR）光谱，并应用硝基苯氧化程序。结果发现，部分木质素和半纤维素在热压过程中分解，但未观察到所得组分对自结合的贡献。此外，还观察到了木质素中缩合反应的进展以及甲醇抽提物中低分子量共轭羰基化合物形成化学键的情况。木质素的热软化也被认为在板材性能的表达中起重要作用。
Self-bonding is the main factor of the performance expression of binderless boards, and therefore its clarification is considered to be an important issue. For this purpose, a series of chemical analyses were conducted on kenaf core binderless boards and their chemical changes during the hot-pressing process are discussed in this article. First of all, binderless boards were prepared from kenaf core powder at different pressing temperatures (without steam-explosion process) and were used for chemical analyses after they were reduced into powders and extracted with methanol. To investigate their chemical changes, lignin, holocellulose, and neutral sugar contents were determined, Fourier transform infrared (FTIR) spectra were recorded, and the nitrobenzene oxidation procedure was applied. As a result, it was found that parts of lignin and hemicelullose were decomposed during the hot-pressing process; however, the contribution of the resulting fractions to selfbonding was not observed. In addition, progress of condensation reactions in lignin and the formation of chemical bonds by low molecular weight conjugated carbonyl compounds in methanol extractives were observed. Thermal softening of lignin is also suggested to play an important role in the expression of board performance.