碱刻蚀玄武岩纤维对地质聚合物基木材胶黏剂胶接性能的影响

Effect of Basalt Fiber by Alkali Etching on Bonding Properties of Geopolymer-Based Wood Adhesives

作为新型环保无机胶凝材料,地质聚合物在人造板产业中具有巨大的应用潜力,但地质聚合物的脆性不利于其与木材胶接。本文以改善地质聚合物基体的脆性,增强其与木材胶接强度为目的,采用不同浓度及温度的NaOH溶液对玄武岩纤维(BF)进行碱刻蚀,将碱刻蚀玄武岩纤维(HAF)与碱激发剂共混,制备碱刻蚀玄武岩纤维掺杂的地质聚合物(HAFMG),探究碱刻蚀方法对HAFMG的力学性能及HAFMG与木材胶接强度的影响。结果表明:碱刻蚀处理可溶解BF表面的硅铝组分,提高BF表面粗糙程度及其与地质聚合物基体的界面结合,最终提高地质聚合物与木材的胶接强度。掺入HAF(100℃、0.5 mol/L NaOH)可提高地质聚合物基体的韧性,相较于纯地质聚合物,其抗折强度提高了154%,压折比降低了41%。HAF(100℃、0.5 mol/L NaOH)掺杂后的地质聚合物与木材的剪切强度相比于纯地质聚合物提高了121%。

As a new environment-friendly inorganic cementitious material,the geopolymer has great application potential in wood-based panel industry.However,the high brittleness limits its bonding property with wood.In order to improve the brittleness of geopolymer matrix and enhance its bonding property,alkali etching modification on the basalt fiber(BF)was used in this study.The basalt fiber was first etched by NaOH solution with different concentrations under different temperatures,and then the basalt fiber etched by alkali(HAF)was mixed with alkali activator,after which the geopolymer modified by basalt fiber(HAFMG)was prepared by adding metakaolin.The effect of alkali etching method on the mechanical property of HAFMG as well as bonding strength between HAFMG and wood was explored.The results show that alkali etching dissolves the silicon and aluminum components on the surface of BF,improves the surface roughness of BF and its interface combination with geopolymer matrix,and finally improves the bonding strength between the geopolymer and wood.Compared with the pure geopolymer,the geopolymer with the addition of HAF(100℃,0.5 mol/L NaOH)has greater toughness.Its flexural strength increases by 154%,and the compression-flexure ratio is reduced by 41%.In addition,the shear strength of the geopolymer modified by HAF(100℃,0.5 mol/L NaOH)is 121%higher than that of the pure geopolymer.