Improvement of wood properties by composite of diatomite and “phenol-melamine-formaldehyde” co-condensed resin

We improved the overall performance of fast-growing poplar by utilizing a low-cost, effective and simple method. The fast-growing poplar was modified by a vacuum-pressure impregnation method with three types of modification solutions composed of phe- nol-melamine-formaldehyde （PMF） co-condensed resin, diatomite, and 3-aminopropyl （diethoxy） methylsilane. We measured the weight percent gain （WPG）, bulking, leaching, anti-swelling efficiency （ASE）, wa- ter-repellent effectiveness （WRE）, and oxygen index of the modified specimens. All of the wood physical properties, which are beneficial for human uses, were significantly improved by the treatment. We improved various characteristics of wood and the oxygen index of poplar above 48.6% after the modification using diatomite and PMF co-condensed resin.

低分子量酚醛树脂改性速生杨试验

用低分子量酚醛树脂浸渍处理速生杨以提高其尺寸稳定性及某些力学性质.通过正交试验对不同甲醛与苯酚物质的量比、加入Na OH量和PVA量3个因素下所制备的低分子量酚醛树脂浸渍速生杨,并压制层积材测定其胶合强度、静曲强度、弹性模量.试验结果表明:低分子量酚醛树脂改性速生杨的最佳工艺条件为n(甲醛)∶n(苯酚)为2.4,n(Na OH)∶n(苯酚)为0.05,PVA质量占苯酚质量的3%,在该条件下速生杨试件的各项性能都得到了提高,能够满足室外木结构用材的要求.

钢板增强速生杨胶合木梁受弯性能

为研究钢板增强速生杨胶合木梁的受弯性能,考虑配钢位置和钢板层数的影响,进行梁的四点弯曲静力载荷试验,采用有限元软件Abaqus对速生杨胶合木梁进行模拟分析。结果表明:改变配钢位置对试件的极限载荷和极限挠度影响较大,其中在受拉区和受压区都配置钢板,对提高试件的极限承载力和极限挠度的效果更明显;随着钢板层数的增加,试件的极限载荷得到有效提高,极限挠度逐渐降低;改变配钢位置和增加配钢层数能有效提高试件的刚度,增加配钢层数对提高试件刚度的效果更为明显。