冰醋酸/双氧水改性竹材物理力学性能及化学成分分析

Analysis of Mechanical Properties and Chemical Composition of Bamboo Flakes after Softening Treatment

【目的】为研究不同改性剂配比、冰醋酸浓度、处理时间和温度对竹材的顺纹抗弯强度、顺纹抗拉强度以及硬度的影响,测定其抗弯强度、抗拉强度及硬度改性处理前后变化,以期获得合适的铅笔板处理工艺。【方法】以毛竹(Phyllostachys edulis)为原料,采用冰醋酸与双氧水浸渍处理工艺,针对改性竹材的化学成分变化,通过XRD、FTIR、TG仪器对改性竹材的化学成分及改性效果进行了表征。【结果】改性竹材抗弯强度和抗拉强度分别随处理温度、冰醋酸和双氧水含量的升高而降低,相比于对照组抗弯强度平均降低44.5%,抗拉强度平均降低59.9%,硬度平均降低44.81%;TG和DTG热解峰值温度滞后,残渣率下降,说明内部冰醋酸含量增加,纤维素、半纤维素有部分被分解;经XRD分析表明改性竹材的结晶度下降约1.5%,结晶度随着处理温度的升高有所降低;在1250~1377 cm^(-1)区域的甲基、羧基吸收峰和3415 cm^(-1)处羟基吸收峰的增强,表明竹材内部亲水基团增加。【结论】优选改性剂浓度配比为1∶1,处理温度为60℃,处理时间为24 h。

【Objective】In order to study the effects of different proportions of modifiers,glacial acetic acid concentration,treatment time and temperature on the bending strength,tensile strength and hardness of bamboo,to measure the changes of bending strength,tensile strength and hardness before and after modification,soa s to obtain the appropriate pencil plate treatment technology.【Method】Bamboo was used as raw material and impregnated with glacial acetic acid and hydrogen peroxide.The chemical composition and modification effect of modified bamboo were characterized by XRD,FTIR and TG.【Result】The bending strength and tensile strength of modified bamboo decreased with the increase of temperature,glacial acetic acid and hydrogen peroxide content,respectively.Compared with the control group,the bending strength and tensile strength of modified bamboo decreased by 44.5%,59.9%and 44.81%respectively.The peak pyrolysis temperature of TG and DTG lagged behind,and the residue rate decreased,indicating that the content of glacial acetic acid increased,and some cellulose and hemicellulose were decomposed.XRD analysis showed that the crystallinity of modified bamboo decreased by about 1.5%,and the crystallinity decreases with the increase of treatment temperature.The enhancement of methyl and carboxyl absorption peaked at 1250-1377 cm^(-1) and hydroxyl absorption peaked at 3415 cm^(-1) indicated the increase of hydrophilic groups in bamboo.【Conclusion】The optimal modifier concentration ratio was 1∶1,treatment temperature was 60℃,and treatment time was 24 hours.