竹材加工剩余物苯甲基化改性试验

以竹子开条、开片或拉丝加工过程产生的长条状剩余物为研究对象,采用低温碱液润胀、苄化处理试验,系统研究了预处理及苄化反应条件对竹材增重率(苄化率)的影响;并借助FTIR、X-射线、SEM、DSC等现代分析手段研究分析了苄化竹材的微观结构、化学结构特征及热熔特征的变化规律。试验结果表明:碱液润胀工艺对竹材苄化增重率的影响最大,苄化试剂用量与反应时间对竹材苄化也有不同程度的作用。在试验范围内较佳的工艺条件为:碱液浓度22.5%、润胀时间10 h、苄化试剂用量50 mL、反应时间1 h。苄化增重率不同,苄化竹材的玻璃化转变温度有显著差异。将苄化增重率45%～50%的变性竹材按同纤维方向重组,可在温度为140℃、单位压力2.0MPa的条件下热压熔接成板。

Study on modified benzylation to bamboo residues

In this study,strip-shaped bamboo residues were subjected to low-temperature alkaline swelling and benzylation treatment.Influence of pretreatment and reaction condition on weight percentage gain(WPG) of bamboo was investigated.The microstructure,chemical structure and hot-melt characteristics of the modified bamboo were studied by means of FTIR,X-ray,SEM and DSC analyses.The results showed that the WPG of bamboo was mainly determined by alkaline swelling process,and was also influenced by the reagent amount and reaction time.The optimum treatment process was obtained when the alkaline solution concentration,swelling time,reagent amount and reaction time were 22.5%,10h,50 mL and 1h,respectively.The glass transition temperature of the modified bamboo was significantly influenced by WPG.The modified bamboo with a WPG of 45%-50% could be reconstituted in the grain direction and pressed to boards at a temperature of 140 ℃ and pressure of 2.0 MPa.