弱酸性条件起始合成脲醛树脂的工艺

Synthetic Technology of Urea-formaldehyde Resin under Initial Weak Acidity Conditions

采用L9(34)正交试验优化弱酸性条件起始合成脲醛树脂的工艺,确定弱酸性条件起始合成脲醛树脂工艺。结果表明:起始pH值对脲醛树脂性能影响最大,弱酸性条件起始合成脲醛树脂最佳工艺条件是pH=6.5、T=90℃和t=4.5h,胶合板甲醛释放量为1.2mg/L,达到GB/T9846.3—2004中E1级标准要求。

The factors affecting the synthesis of urea-formaldehyde under initial weak acidity conditions were studied using the orthogonal test of L9 （3^4）. The synthetic technology of urea-formaldehyde resin was determined. Results showed that the initial pH value had notable effect on the performances of urea-formaldehyde resin. The optimal synthetic conditions were obtained as pH value 6.5, reaction temperature 90 degrees C, and reaction time 4.5 hours. The formaldehyde emission of the plywood was 1.2 mg/L under this optimal condition, which reached the requirement of E1 grade wood for GB/T 9846.3--2004.