【作者】 沈亮亮；

【导师】 王传贵； 刘君良；

【作者基本信息】 安徽农业大学 ， 木材科学与技术， 2007， 硕士

【摘要】 本文通过对毛竹材(Phyllostachys pubescens)进行微波软化处理,然后通过热压密实的方法将其压缩,并对压缩后竹材样品的化学成分、结晶度、表面接触角进行分析和扫描电镜观察。并且对竹材进行三聚氰胺树脂浸渍处理,然后进行热压密实,将其与直接密实的竹材进行密度、抗弯强度、抗弯弹性模量、吸水厚度膨胀率的比较。得出:(1)竹材采用微波软化,软化功率350W,时间4～5min,软化后竹片含水率约为20%。软化处理效果好。(2)竹材压缩率对其吸水厚度膨胀率和压缩变形恢复率的影响较显著,随压缩率的增加吸水厚度膨胀率和压缩变形恢复率逐渐增大。(3)热压温度对吸水厚度膨胀率和压缩变形恢复率也有一定的影响。温度越高其吸水厚度膨胀率和压缩变形恢复率越小,并且随着温度升高,竹龄越短其吸水厚度膨胀率和压缩变形恢复率越小。(4)热压定型时间对吸水厚度膨胀率和压缩变形恢复率无明显影响。(5)竹材在经过热压处理后,其密度、静曲强度和抗弯弹性模量均得到提高。(6)未经过树脂浸渍的竹材在热压压缩率为10%-20%之间时,竹材的密度在0.8～1.0g/cm~3左右,弹性模量在8GPa～10GPa之间,抗弯强度在150MPa-200MPa之间。密度比素材提高了25%～50%左右,弹性模量比素材提高提高了30%～55%左右,抗弯强度比素材提高了30%～55%左右。(7)经过树脂处理的竹材经过相同条件的热压后,在压缩率为20%左右密度、弹性模量和静曲强度分别达到0.95g/cm~3,15GPa和227MPa。分别比未压缩材提高了36%,116%,74%。(8)通过吸水厚度膨胀率的比较可知,树脂处理后的竹材压缩后,在压缩率小于10%时,其吸水厚度膨胀率比未处理材相比小66.6%,在压缩率为10%～15%时,与未处理材相比小63.2%。(9)经过微波软化处理热压密实后的竹材其抽提物含量明显比未处理材减少。(10)密实后的竹材其结晶度比未处理材增大,在温度为120℃-200℃之间变化时随着热压温度的升高,结晶度呈增大的趋势,一般来说结晶度越大,强度越大。(11)通过对竹材表面接触角的分析,可以得出竹材在经过微波软化、热压处理后,表面自由能比未处理材增大。更多还原

【Abstract】 This thesis study the bamboo which was treated with microwave heating and hot pressing.The chemical composition,crystallinity,the surface wettability and SEM observing of compressed bamboo were analyzed.The melamine resin adhesive were impregnated in the bamboo and pressed it.The density,MOR,MOE,the index of thickness swelling were compared between bamboo and pressed bamboo.The result indicated:(1)The optimum technology parameters of microwave is 350w in heating power;4-5min in heating time;20%in moisture.(2)The influence of compression rate to the thickness swelling and compressive deformation recovery efficiency were remarkably. The thickness swelling and compressive deformation recovery efficiency is increased with the increase of compression rate.(3)Hot compressing temperature and the age of bamboo is affected the thickness swelling and compressive deformation recovery efficiency in a certain degree.The high of hot compressing temperature and the young of age,the decrease of thickness swelling and compressive deformation recovery efficiency.(4)Compressed time affected the thickness swelling and compressive deformation recovery efficiency were insignificant.(5)After hot compressed,the index of density,MOR,MOE of bamboo is increased.(6)Through the hot pressing,when the compression rate is 10%～20%,the density of no-treated bamboo is 0.8-1.0g/cm3,MOR is 8-10Gpa,MOE is 150-200Mpa.Compared to the no pressed bamboo,the density is increased 25%-50%,MOR is increased 30%-55%,MOE is increased 30%-55%.(7)The resin treated bamboo through the hot pressing,when it’s compression rate is 20%,the density is 0.95g/cm~3,MOR is 15Gpa,MOE is 227Mpa.Compared to the no pressed bamboo,is respectively increased 36%,116%,74%.(8)Compared to the untreated bamboo, the thickness swelling of the resin treated bamboo through the hot pressing,when it’s compression rate is 10%,the index reduced 66.6%;when its compression rate is 10%-15%,the index reduced 63.2%.(9)Through the microwave heating the extraction is reduced to the untreated bamboo.(10)The crystallinity of compressed bamboo is increased,when the temperature increased,the crystallinity increased,the mechanics strength increased.(11)Through the surface contact angle of bamboo,the result indicated after microwave heating,the surface free energe increased.更多还原