摘要
为了研究在降低木基复合材料密度的同时而不降低材料的力学性能,该文利用聚合物发泡技术与人造板工艺技术相结合的技术路线开展木基发泡复合材料的制备及研究.利用扫描电镜对复合材料的微观构造进行了分析;同时,以静曲强度、弹性模量、冲击强度和2 h吸水厚度膨胀率作为主要指标对发泡复合材料的性能进行评价,考察发泡对材料性能的影响.结果表明:①木基发泡复合材料内部纤维交织疏松,纤维间主要通过泡孔连接增强,泡孔增加了纤维之间的相互作用,从而使材料强度增加,且纤维间距较大处填充有泡孔结构体.②胶粘剂与发泡剂总含量在20%时,静曲强度、弹性模量和冲击强度最好,2 h吸水厚度膨胀率却较大;热压温度在120℃效果最好,温度过低,发泡不完全,温度过高,在一定压力下部分泡孔出现塌泡现象,所以性能均有所下降;热压时间15 min效果最佳.经方差和极差分析知,F值的最佳工艺条件为:胶粘剂与发泡剂总含量20%、热压温度120℃、热压时间15min.在此工艺条件下,木基发泡复合材料性能均达到相关标准.
In order to reduce the density of wood-based composites without causing a deterioration of their mechanical properties, this paper studied the process of manufacturing wood-based composites. A combination of polymer foaming technology and man-made panel technology was used. The microscopic structure of the various wood-based composites was analyzed with a scanning electron microscopel （SEM）. Bending strength （MOR）, modulus of elasticity （MOE）, impact strength, and thickness expansion rate of water sorption （ TS ） were all measured. The results showed that fibers loosely interweave, fibers had been connected by micropore, interaction of fibers was increased through micropore. They also showed that spaces between fibres had big micropore structures. MOR, MOE and impact were the highest among three levels of ratio. When the content of the bonding agent and foaming agent were 20 % by weight, thickness expansion rate of water sorption （TS） was higher. A hot-pressing temperature of 120℃ was the best among three levels of temperature. At extremely low temperatures, the foaming process was incompletion; at extremely high temperatures, micropores bursted at a certain pressure. A hot-pressing time of 15 min was the best among three levels of time. Based on the variance analysis and maximum difference analysis, a significance test shows the optimum conditions for the content of bonding agent, and foaming agent is 20% by weight, with a hot pressing temperature of 120℃ for 15 min. Under these conditions, the properties of wood-based foaming composites all achieved standard.
出处
《北京林业大学学报》
EI
CAS
CSCD
北大核心
2007年第3期154-158,共5页
Journal of Beijing Forestry University
基金
"863"国家高技术研究发展计划(2002AA245141)
关键词
发泡
木基复合材料
微观构造
性能
foaming, wood-based composites, microscopic structure, properties
