Megiatto Jackson D, Hoareau William, Gardrat Christian, Frollini Elisabete, Castellan Alain
Instituto de Química de São Carlos, Universidade de São Paulo, USP, C.P. 780, CEP 13560-970 São Carlos, SP, Brazil.
J Agric Food Chem. 2007 Oct 17;55(21):8576-84. doi: 10.1021/jf071682d. Epub 2007 Sep 15.
Sisal fibers have one of the greatest potentials among other lignocellulosic fibers to reinforce polymer matrices in composites. Sisal fibers have been modified to improve their compatibility with phenolic polymer matrices using furfuryl alcohol (FA) and polyfurfuryl alcohols (PFA) that can be obtained from renewable sources. The modification corresponded first to oxidation with ClO 2, which reacts mainly with guaiacyl and syringyl units of lignin, generating o- and p-quinones and muconic derivatives, followed by reaction with FA or PFA. The FA and PFA modified fibers presented a thin similar layer, indicating the polymer character of the coating. The untreated and treated sisal fibers were characterized by (13)C CP-MAS NMR spectrometry, thermal analysis, and scanning electron microscopy. Furthermore, for a better understanding of the reactions involved in the FA and PFA modifications, the sisal lignin previously extracted was also submitted to those reactions and characterized. The characterization of isolated lignin and hemicellulose provides some information on the chemical structure of the main constitutive macrocomponents of sisal fibers, such information being scarce in the literature.
剑麻纤维在其他木质纤维素纤维中具有增强复合材料中聚合物基体的最大潜力之一。剑麻纤维已通过糠醇（FA）和聚糠醇（PFA）进行改性，以提高其与酚醛聚合物基体的相容性，FA和PFA可从可再生资源中获得。改性首先对应于用ClO₂进行氧化，ClO₂主要与木质素的愈创木基和紫丁香基单元反应，生成邻醌和对醌以及粘康酸衍生物，随后与FA或PFA反应。经FA和PFA改性的纤维呈现出一层相似的薄层，表明涂层具有聚合物特性。通过¹³C CP - MAS NMR光谱法、热分析和扫描电子显微镜对未处理和处理过的剑麻纤维进行了表征。此外，为了更好地理解FA和PFA改性中涉及的反应，之前提取的剑麻木质素也进行了这些反应并进行了表征。对分离出的木质素和半纤维素的表征提供了一些关于剑麻纤维主要组成宏观成分化学结构的信息，而此类信息在文献中较为匮乏。
