低毒脲醛树脂胶的合成及胶液中游离甲醛的测定

探讨了改性剂对降低游离甲醛含量、改善胶粘剂性能的作用机理,研究了三聚氰胺、聚乙烯醇（PVA）改性脲醛树脂胶粘剂（UF胶）的制备工艺和配方,实验得出：采用弱碱-弱酸-弱碱的工艺,添加适量三聚氰胺和聚乙烯醇,反应最高温度控制在90℃,反应时间2~3 h,n（尿素）∶n（甲醛）=1∶1.4,尿素按7.0∶2.0∶1.0的质量比分3次投料,可制得低毒脲醛树脂胶粘剂。

Synthesis of Low Toxicity Urea-formaldehyde Resin Adhesive and Determination of Free Formaldehyde in Adhesive

The action mechanism of modifier to reduce free formaldehyde content and to improve the adhesive properties was discussed.Preparation techniques and recipes of modifying urea-formaldehyde resin adhesives（UF glue） with melamine and polyvinyl alcohol（PVA） were introduced.The results show that when adding appropriate amount of melamine and polyvinyl alcohol,the reaction maximum temperature is controlled at 90 ℃,reaction time is 2~3 h,volume ratio of urea and formaldehyde is 1∶1.4, urea is added in mass ratio 7. 0： 2. 0： 1.0 by 3 times, low toxicity urea - formaldehyde resin adhesive can be obtained by the weak base - weak acid - weak base process.