Effects of cellulose, hemicellulose, and lignin on the morphology and mechanical properties of metakaolin-based geopolymer
Effects of cellulose, hemicellulose, and lignin on the morphology and mechanical properties of metakaolin-based geopolymer
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DOI：
10.1016/j.conbuildmat.2018.04.028
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发表时间：
2018-06
影响因子：
7.4
通讯作者：
Hanzhou Ye;Zhang Yang;Y. Zhiming;Jun Mu
中科院分区：
文献类型：
--
作者：
Hanzhou Ye;Zhang Yang;Y. Zhiming;Jun Mu
天然纤维增强地聚合物以其低成本、低密度、优异的力学性能在建筑材料领域受到广泛关注。纤维素、半纤维素和木质素是天然纤维的三种基本成分，研究了它们对偏高岭土基地聚合物的影响。通过形貌分析和机械强度分析进行对比评价。结果表明，以纤维素、半纤维素和木质素为主要成分的地聚合物基材料具有不同的微观结构和力学性能。木质素、纤维素和半纤维素的低含量（5 wt%）提高了纯地聚合物的抗弯和抗压强度。较高的木质素和半纤维素含量会导致地聚合物基复合材料的多孔形态、较低的密度和脆性断裂，从而降低了这些地聚合物基复合材料的抗折和抗压强度。结果表明，半纤维素经碱性降解后，地聚合度明显降低。相反，随着纤维素含量的增加，地聚合物基体的结构更致密，孔隙更少，地聚合物基复合材料的延性破坏也更明显。地聚合物基体与纤维素纤维结合良好，降解不明显。本研究结果将有助于更好地了解木质纤维素生物质在天然纤维增强地聚合物中的作用，并为进一步的研究和应用奠定基础。
Natural fiber-reinforced geopolymer has attracted wide attention in construction and building materials due to its low cost, low density, and excellent mechanical properties. Cellulose, hemicellulose, and lignin are the three basic components of natural fibres, and were investigated to reveal their influence on the metakaolin-based geopolymer. Comparative evaluations were investigated via morphology analysis and mechanical strength analysis. The results showed distinct microstructures and mechanical properties of the geopolymer-based materials with cellulose, hemicellulose, and lignin, respectively. A low content (5 wt%) of lignin, cellulose, and hemicellulose enhanced the flexural and compressive strength of pure geopolymer. Higher lignin and hemicellulose led to the porous morphology, lower density, and brittle fractures of geopolymer-based composites, which reduced the flexural and compressive strength in these geopolymer-based composites. It was noted that the degree of geopolymerization was clearly lowered by the alkaline degradation of hemicellulose. With the increase in cellulose content, in contrast, the denser structure and fewer pores of the geopolymer matrix were detected, as well as ductile failures of geopolymer-based composites. Good bonding was also shown between the geopolymer matrix and cellulose fibres without remarkable degradation. The results of this study will facilitate a better understanding of the effect of lignocellulosic biomass in natural fibre-reinforced geopolymers and should serve as the basis for further research and applications.