摘要
为解决醛系合成树脂胶黏剂甲醛释放、热稳定性差和阻燃效果较差的难题,探讨了一种功能叠加型无机镁质胶黏剂的制备技术,以期替代醛类合成树脂胶黏剂在木材工业上的使用。本研究中镁质胶黏剂的优化配方为n(MgO)/n(MgCl 2)=6,n(H 2 O)/n(MgCl 2)=16,胶合板制备工艺为施胶量700 g/m 2(双面),冷压时间28 h,养护时间15 d。试验结果显示,养护天数对镁质胶黏剂制备胶合板胶合强度的影响最显著。当养护天数为3~19 d时,胶合板的干、湿胶合强度均呈现先增大后下降的趋势,13 d时干、湿胶合强度均达到峰值,干、湿胶合强度分别为1.40和1.08 MPa。通过对胶合板剪切破坏界面进行扫描电镜观察发现,镁质胶黏剂渗透到木材孔隙中形成了胶钉,产生了机械咬合结构。利用热重分析仪和锥形量热仪等对镁质胶黏剂的热稳定性和燃烧性能进行了测试,结果表明,镁质胶黏剂在本研究温度范围(30~800℃)内的总质量损失率为48%。在50 kW/m 2的热辐射功率下,镁质胶黏剂制备胶合板的平均热释放速率(HRR)为35.84 kW/m 2,总热释放量(THR)为20.97 MJ/m 2。与普通酚醛树脂胶黏剂相比,镁质胶黏剂具有较好的热稳定性和阻燃性能。
The aldehyde adhesive commonly used in plywood industry has some obvious drawbacks such as high formaldehyde release,poor thermal stability and low flame retardancy.This study discussed the preparation technology for a kind of functional superimposed inorganic magnesium adhesive,which was environmentally friendly,high temperature resistant,fireproof and anti-aging to replace the use of aldehyde organic adhesives.In this study,the optimized formulation of magnesium adhesive and manufacturing parameters of plywood were obtained through the orthogonal test and the results were as follows:n(MgO)/n(MgCl 2)=6,n(H 2 O)/n(MgCl 2)=16,the adhesive consumption was 700 g/m 2(both sides),the cold-pressing time was 28 h,and the curing day was 15 d.The variance analysis results showed that the curing day had the most significant effect on the bonding strength of the plywood manufactured with magnesium adhesive.The single factor test was used to further investigate the effect of curing days on the properties of magnesium adhesive.The results showed that when the range of curing days was between 3 d and 19 d,both the dry bonding strength and wet bonding strength of plywood firstly increased and then decreased.At 13 d,the dry and wet bonding strengths reached peak values of 1.40 MPa and 1.08 MPa,respectively.However,the water resistance decreased with the increase of curing days.Through the observation of the shear failure interface of plywood by the scanning electron microscope,it was found that the magnesium adhesive penetrated the pores of wood and formed the adhesive nail,generating mechanical occlusion.When the formulation of magnesium adhesive and manufacturing parameters were reasonable,the bonding strength between wood and magnesium adhesive was larger than the tensile strength of wood.The thermal stability of magnesium adhesive was examined by the thermogravimetric analyzer.The analysis showed that the total mass loss rate of magnesium adhesive was 48%in the studied temperature range(30-800℃).The combustion properties of magnesium adhesive manufactured plywood were tested by the cone calorimeter.Under the thermal radiation power of 50 kW/m 2,the average heat release rate(HRR)of plywood was 35.84 kW/m 2,and the total heat release(THR)was 20.97 MJ/m 2.The above results proved the superiority of magnesium adhesive compared with the traditional phenolic adhesives in terms of thermal stability and flame retardancy.The results of this study can provide theoretical guidance for the manufacturing of magnesium adhesive plywood.
作者
吴丹妮
孙萍
郑妮华
刘红光
李黎
牛耕芜
WU Danni;SUN Ping;ZHENG Nihua;LIU Hongguang;LI Li;NIU Gengwu(College of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China;School of Materials Science and Art Design,Inner Mongolia Agricultural University,Hohhot 010018,China)
出处
《林业工程学报》
CSCD
北大核心
2020年第2期54-61,共8页
Journal of Forestry Engineering
基金
中央高校基本科研业务费专项基金(2017JC11)
国家自然科学基金(31770602)
关键词
镁质胶黏剂
胶合板
胶合强度
热稳定性
阻燃性能
magnesium adhesive
plywood
bonding strength
thermal stability
flame retardancy
作者简介
吴丹妮,女,研究方向为木质复合材料与胶黏剂;通信作者:牛耕芜,男,副教授。E-mail:niugw@163.com。
