摘要
以竹炭为原料、氯氧镁水泥为胶黏剂,通过热压成型的方式探索氯氧镁水泥竹炭板的制备工艺。研究了氯氧镁水泥配比、竹炭粒径以及竹炭质量分数等因素对竹炭板静曲强度、剖面密度、甲醛吸附率、吸水率以及24 h吸水膨胀率等性能的影响,最终得到氯氧镁水泥竹炭板较优的制备工艺参数。研究结果表明:氯氧镁水泥的最优物质的量配比确定为n(MgO)∶n(MgCl_(2)·6H_(2)O)∶n(H_(2)O)=7∶1∶10;在试验范围内,筛选得到竹炭粒径为27~60目且质量分数为45%时氯氧镁水泥与竹炭比例最佳,制得的竹炭板静曲强度可达6.14 MPa,质地均匀且致密;竹炭板依然保有竹炭的吸附功能,竹炭板对甲醛的吸附性能和吸水率随着竹炭粒径的减小呈现先增后减的趋势,在竹炭粒径为14~24目时最高,甲醛吸附率最高为1.85%,同时竹炭板具有良好的尺寸稳定性,24 h吸水膨胀率均低于0.5%;通过对竹炭板的微观结构进行扫描电镜观察发现,氯氧镁水泥能够进入竹炭孔径内部,以胶钉的形式来形成胶接强度。
In order to search for the feasible techniques of making inorganic bamboo charcoal-based boards,enrich the related research of bamboo charcoal-based boards and enhance the economic value-added for bamboo charcoals,this study used bamboo charcoals as raw materials and magnesium oxychloride cement as adhesive to prepare bamboo charcoal-based boards.The effects of ratio of magnesium oxychloride cement,bamboo charcoal particle size and content on mechanical properties,vertical density profile,formaldehyde adsorption rate,24 h water absorption rate and 24 h water swelling rate of bamboo charcoal-based boards were studied,to provide related manufacturing parameters and theoretical basis for the practical production.The micromorphology of bamboo charcoal-based boards was observed with the scanning electron microscope.The results showed that:the optimal mole ratio of magnesium oxychloride cement as adhesive was determined to be n(MgO)∶n(MgCl_(2)·6H_(2)O)∶n(H_(2)O)=7∶1∶10 after comparing the flexural strength and softening coefficient of the magnesium oxychloride cement samples with different mole ratios.It was found that there was positive correlation between the bending strength and tap-density under the limitted meshes.The larger tap-density meant the smaller vacant volume which needed magnesium oxychloride cement to fill in and form bond strength between bamboo charcoal particles among the stacked bamboo charcoals.The bending strength of bamboo charcoal-based boards made by 27-60 mesh bamboo charcoals was the highest among the different particle sizes.The profile density and bending strength were close when the of bamboo charcoals content increased from 40%to 45%.So the 45%content of bamboo charcoal was an economical and applicable parameter for preparing bamboo charcoal-based boards,and the bending strength of bamboo charcoal-based boards was about 6.14 MPa and the vertical density profile was around 1.1 g/cm^(3) when the particle size and content of bamboo charcoals was 27-60 mesh and 45%,respectively.The formaldehyde adsorption rate and 24 h water absorption of magnesium oxychloride cement-bamboo charcoal composite boards increased firstly and then decreased with the decreasing of the particle size of bamboo charcoals,and reached the max when the particle size of bamboo charcoal was about 14-24 mesh.The highest formaldehyde adsorption rate was 1.85%.Furthermore,the 24 h swelling rates of bamboo charcoal-based boards were all under 0.5%,which showed fairly good dimensional stability.Using the scanning electron microscope,it was revealed that the hydration products of magnesium oxychloride cement could infiltrate into the pore inside bamboo charcoals and form bonding strength through the form of glue nails by biting the inwall of pore of bamboo charcoals.
作者
周海瑛
江文正
李文珠
张文标
ZHOU Haiying;JIANG Wenzheng;LI Wenzhu;ZHANG Wenbiao(School of Engineering,Zhejiang A&F University,Hangzhou 311300,China)
出处
《林业工程学报》
CSCD
北大核心
2021年第6期66-73,共8页
Journal of Forestry Engineering
基金
浙江省重点研发计划项目(2018C02008)。
关键词
氯氧镁水泥
竹炭板
甲醛吸附率
物理力学性能
剖面密度
magnesium oxychloride cement
bamboo charcoal-based board
formaldehyde adsorption rate
physical and mechanical properties
vertical density profile
