超低甲醛释放木质素基胶黏剂的制备及应用  

Preparation and Application of Lignin-based Adhesives with Ultra-low Formaldehyde Emission

作　　者：高士帅[1] 谢宜彤 张代晖 储富祥[1] 王春鹏[1] GAO Shishuai;XIE Yitong;ZHANG Daihui;CHU Fuxiang;WANG Chunpeng(Institute of Chemical Industry of Forest Products,CAF,Key Lab.of Biomass Energy and Material,Jiangsu Province,Key Lab.of Chemical Engineering of Forest Products,National Forestry and Grassland Administration,National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass,Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,Nanjing 210042,China)

机构地区：[1]中国林业科学研究院林产化学工业研究所、江苏省生物质能源与材料重点实验室,国家林业和草原局林产化学工程重点实验室、林木生物质低碳高效利用国家工程研究中心、江苏省林业资源高效加工利用协同创新中心,江苏南京210042

出　　处：《林产化学与工业》2024年第4期29-35,共7页Chemistry and Industry of Forest Products

基　　金：中国林科院中央级公益性科研院所基本科研业务费专项资金重点项目(CAFYBB2021ZI001)。

摘　　要：针对脲醛树脂耐水、耐候性能差和潜在甲醛释放的问题,以工业碱木质素(L)为原料,通过与苯酚(P)、尿素(U)和甲醛(F)共缩聚反应制备了符合ENF级Ⅰ类胶合板要求的木质素基胶黏剂(LPUs)。考察了L、P和U质量比对LPUs凝胶时间、游离甲醛含量、储存稳定性、固化反应活性以及胶合板理化性能的影响。结果表明:mL/(mP+mU)为1∶1时制备的树脂LPU1~LPU4中,随着尿素用量的增加,LPUs树脂的凝胶时间逐渐缩短,m(P)∶m(U)=30∶70时制备的LPU4,其凝胶时间为(18±2)min,约为LPU1(m(P)∶m(U)=90∶10)的凝胶时间(30±2)min的40%,游离甲醛含量从0.05%(LPU1)升高至0.18%,储存期由127 d缩短至14 d,表现出脲醛树脂的理化特性。DSC监测固化过程焓变行为表明,LPUs树脂反应活化能仅为商业酚醛树脂和脲醛树脂的2%~7.8%。mL/(mP+mU)=1且苯酚用量不低于尿素时制备的LPU1~LPU3树脂胶合板耐沸水胶合强度和甲醛释放量满足ENF级Ⅰ类胶合板要求,其中LPU2树脂的施胶量可降低至工业生产工艺的66.7%,此时,依然可以确保胶合板的耐沸水胶合强度和甲醛释放量满足ENF级Ⅰ类要求,可有效降低胶合板生产成本。In order to address the problems of water resistance,poor weather resistance and potential formaldehyde release of urea-formaldehyde resins,lignin-based adhesives(LPUs)with ultra-low formaldehyde emission meeting the requirements of E NF gradeⅠplywood were prepared by co-condensation with phenol(P),urea(U)and industrial alkali lignin(L).The effects of L,P and U mass ratio on the gel time,free formaldehyde content,storage stability,curing reaction activity and physicochemical properties of LPUs were investigated.The results showed that the maximum ratio of m L/(m P+m U)was up to 1∶1.With the decreasing mass ratio of P and U,the gel time of LPUs resin was gradually shortened by 40%,the free formaldehyde content increased from 0.05%to 0.18%,and the storage period was reduced from 127 d to 14 d,showing the physical and chemical properties of urea-formaldehyde resins.The enthalpy change behavior of the curing process monitored by DSC showed that the reaction activation energy of LPUs resin only reached 2%-7.8%of that of commercial phenolic and urea-formaldehyde resins.The boiling water resistance and formaldehyde emission of LPU1-LPU4 resin plywood prepared with m L/(m P+m U)=1 and with the amount of phenol not less than that of urea,met the requirements of E NF gradeⅠplywood.The glue spread of LPU2 resin could be reduced to 66.7%compared to that of the industrial production process.At this time,the boiling water resistance and formaldehyde emission of plywood could still be ensured to meet the requirements of E NF gradeⅠ,which could effectively reduce the production cost of plywood.

关 键 词：木质素 共缩聚反应 胶合板 耐沸水胶合强度 甲醛释放量 

分 类 号：TQ35[化学工程]