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首页> 外文期刊>Journal of Applied Polymer Science >Weathering characteristics of modified rubberwood (Hevea brasiliensis)
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Weathering characteristics of modified rubberwood (Hevea brasiliensis)

机译：改性橡胶木（巴西橡胶树）的风化特性

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Surfaces of rubberwood treated with dilute aqueous solutions of chromium trioxide, chromic nitrate, ferric chloride, and ferric nitrate and modified with acetic anhydride were weathered outdoors for periods from 1 day to 1 year. Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, light microscopy (LM), and scanning electron microscopy (SEM) were used to analyze chemical and microscopic changes in treated and untreated weathered wood surfaces. Severe delignification and hemicellulose degradation occurred in untreated samples, evident from rapid decreases in IR band intensities at 1505 and 1740 cm(-1), respectively. Surface delignification occurred after 1 day's exposure, with severe lignin loss within 2-3 days and almost complete surface delignification after 1 week of exposure. Fluorescence spectra of weathered wood surfaces showed a rapid decrease in intensity and a large red shift in emission maxima. Scanning electron microscopy of untreated wood surfaces exposed for 125 and 360 days showed them to have ridges in the S3 cell-wall layer adjacent to the lumen, together with wall checking and pit degradation. Fungal spores and hyphae were observed in wood cell lumens. Pretreatment of wood surfaces with chromium trioxide (chromium VI compound) significantly restricted weathering deterioration and microbial colonization, whereas ferric chloride was most effective in preventing microbial colonization. Acetylation also partially prevented delignification and fungal staining. (C) 2002 Wiley Periodicals, Inc. [References: 24]
机译：用三氧化铬，硝酸铬，氯化铁和硝酸铁的稀水溶液处理并用乙酸酐改性的橡胶木表面在户外风化1天至1年。傅里叶变换红外（FTIR）光谱，荧光光谱，光学显微镜（LM）和扫描电子显微镜（SEM）用于分析经过处理和未经处理的风化木材表面的化学和微观变化。未经处理的样品中发生严重的脱木素作用和半纤维素降解，这可以从分别在1505和1740 cm（-1）处的IR谱带强度快速下降中看出。暴露1天后发生表面脱木质素，在2-3天之内木质素损失严重，暴露1周后几乎完全脱木质素。风化的木材表面的荧光光谱显示强度快速降低，并且发射最大值出现大的红移。暴露125天和360天的未经处理的木材表面的扫描电子显微镜显示，它们在靠近内腔的S3细胞壁层中具有脊，并且进行了壁检查和凹坑降解。在木细胞腔中观察到真菌孢子和菌丝。用三氧化铬（六价铬化合物）预处理木材表面可显着限制风化作用的恶化和微生物的定殖，而氯化铁在防止微生物定殖方面最有效。乙酰化还部分地防止了脱木质素和真菌染色。 （C）2002 Wiley Periodicals，Inc. [参考：24]

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