麦秸秆成分剖析及其胶合性能的研究

以麦秸为研究对象,将其解剖分层,采用化学分析和现代仪器分析相结合,对其各层进行成分分析,找出其最大差别.同时针对其表面的特殊性,采用两大类共7种不同的偶联剂对其进行处理,以探讨其胶合性能的变化情况.结果表明,与整秆相比,麦秸外层厚度约占20%,其各组分含量均有不同程度的差异,其中灰分含量比整秆高17.2%,而灰分中的SiO2含量更是明显高于整秆的一倍多,苯酚-乙醇(苯-醇)可溶物含量比麦秸整秆的高21.95%;电子自旋共振波谱仪(ESR)测试麦秸整秆的自由基比外层要高,扫描电镜(SEM)可看出麦秆外表面光滑,内表面没有角质层,利于胶滴的润湿、扩散和渗透.偶联剂KH-550对麦秸各层面的胶合均较好,尤其是对外表面的胶合强度提高很大,其他类偶联剂无明显效果.

STUDIES ON LAYER COMPOSITES OF WHEAT STALK AND THEIR ADHESION PROPERTIES

Wheat straw was split into layers,and the chemical composition of each layer was analyzed by chemical and modern instrumental analysis for the purpose to find the differences among layers.Following to the specific characteristics of the outer layer,7 different coupling agents were used to explore the variation of adhesion properties.Results showed that outer layer accounts for 20% thickness of the whole stalk and containes somewhat different contents of components,in which ash content is 21.95% higher than that of the whole stalk,while SiO 2 content in its ash is more than 100% higher than the whole stalk;and phenol-EtOH extractive is 21.95% higher than the whole stalk.ESR (analysis) indicated that free radicals in the whole stalk is higher than outer layer.SEM results demonstrated the smooth cuticle surface of the outer layer,as well as the absence of cuticle on inner layer,and the later is beneficial to wetting,diffusion and permeation of UF resin.The coupling agent KH-550 exhibited good adhesion property toward each layer of the stalk,especially the significant increase of bonding strength toward outer surface,while other coupling agents showed no significant effect.