H-MMT对低物质的量比脲醛树脂胶粘剂性能的影响

Effect of H-MMT on properties of low molar ratio urea-formaldehyde resin adhesive

将蒙脱土进行酸化处理,制备酸化蒙脱土(H-MMT)。随后在低物质的量比脲醛树脂合成体系中,加入制得的H-MMT,得到经H-MMT改性的脲醛树脂胶粘剂。通过控制加入H-MMT的投料比以及投放时间,探究其对脲醛树脂胶粘剂的黏度、固含率、游离甲醛含量以及胶接性能的影响。同时,对比分析了未改性脲醛树脂胶粘剂和H-MMT改性脲醛树脂胶粘剂的差异。研究结果表明:在脲醛树脂合成体系反应的第二阶段加入3%的H-MMT,改性脲醛树脂胶粘剂的性能最好,测得胶粘剂的游离甲醛含量为0.17%,固化时间为57.5 s,胶接强度为1.1 MPa;加入H-MMT的改性脲醛树脂胶粘剂中含有大量的醚键和羟甲基基团,可以提高胶粘剂的胶接性能;H-MMT改性的脲醛树脂胶粘剂中存在着未反应的残留尿素,进一步降低了体系的游离甲醛含量。

Acidified montmorillonite(H-MMT)was prepared by acidified treatment of montmorillonite.Then,the prepared H-MMT was added into the low molar ratio urea-formaldehyde resin synthesis system to obtain the urea-formaldehyde resin adhesive modified by H-MMT.The effects of H-MMT addition on the viscosity,solid content,free formaldehyde content and bonding properties of urea-formaldehyde resin adhesive were investigated by controlling the feeding ratio and release time.At the same time,the differences between unmodified ureaformaldehyde resin adhesive and those modified by H-MMT were compared and analyzed.The research results showed that in the second stage of the reaction in the urea-formaldehyde resin synthesis system,3%H-MMT was added,and the performance of the modified urea-formaldehyde resin adhesive was the best.The free formaldehyde content of the adhesive was measured to be 0.17%,the curing time was 57.5 seconds,and the bonding strength was 1.1 MPa.The modified urea-formaldehyde resin adhesive with the addition of H-MMT contained a large number of ether bonds and hydroxymethyl groups,which could improve the bonding performance of the adhesive.The presence of unreacted residual urea in the H-MMT modified urea-formaldehyde resin adhesive further reduced the free formaldehyde content of the system.