DDAC改性蒙脱土-木材复合材料的应力松弛

Tensile Stress Relaxation of DDAC-modified Montmorillonite/Wood Composite

以二癸基二甲基氯化铵(DDAC)为蒙脱土的改性剂及中间介质,通过真空浸注制备蒙脱土-木材复合材料(MWC),分析不同处理方式试材的增重率、应力松弛和X射线衍射(XRD)表征。结果表明:MWC的增重率基本随着处理液中蒙脱土质量分数的增加而增加,并在有机蒙脱土(OMMT)为7%时,达到最大值;MWC的应力松弛性质发生了明显的变化,其中OMMT的质量分数对MWC应力松弛有较大的影响,质量分数为3%的处理液所处理试件的应力松弛量最小;木材的含水率状态对MWC的应力松弛性能的影响很大,饱水状态与绝干、气干状态相比较,其应力松弛量最大,绝干状态的应力松弛变化曲线最缓慢;蒙脱土未能充分进入到木材内部,但是进入到木材表面空隙或极少量进入到木材内部空隙的蒙脱土对杉木的应力松弛性能产生很大的影响。

Using didecyldimethyl ammonium chloride （DDAC） as modifier and intermediate, the montmorillonite/wood composites （MWC） were prepared through vacuum impregnation and the percentage of weight gain, tensile stress relaxation and interlayer distance of the specimens after different methods of treatment were analyzed. The resuh showed that the percentage of weight gain rate increased as concentration of organic montmorillonite （OMMT） increased and reached its maximum at an OMMT concentration of 7 %. Stress relaxation of MWC was obviously changed and greatly affected by the concentration of OMMT. The smallest stress relaxation was observed at an OMMT concentration of 3 %. Water content also played an important role in the stress relaxation of the WMC. Wet wood appeared the most obvious stress relaxation compared to air-dried and oven-dry woods. Although OMMT did not infiltrate into the inside of wood thoroughly, the montmorillonite（MMT） attached on the surface of wood or the small amount of MMT entering into the inner cell cavities of wood still improved the stress relaxation of wood to a great extent.