摘要
普通脲醛树脂及氧化淀粉改性脲醛树脂的合成工艺中 ,酸度控制条件对合成产物稳定性、剪切强度、游离甲醛含量等性能影响的研究表明 ,缩合反应阶段尿素投入时体系pH值对脲醛树脂合成过程以及产物稳定性都有显著性影响。缩合阶段体系的pH值控制范围直接影响脲醛树脂的稳定性、粘合强度与游离甲醛含量。从脲醛树脂稳定性考虑 ,投入第三批尿素后的pH值应控制在 6 .
In this paper, the influence of acidity control condition on stability, shear strength and free formaldehyde content of synthesis product in common UF resins synthesis process and in oxidation starch improving the properties of UF resins synthesis process was discussed. The experimental results show that in the condensation reaction pH value of system has remarkable influence on the synthesis process of UF resins and stability of its product when urea was added. pH value range of system directly influence resin stability, bond strength and free formaldehyde content. Taking account of stability of UF resins. the pH value should be controlled above 6.0 after the third batch urea was added.
出处
《中国胶粘剂》
CAS
2002年第4期21-23,共3页
China Adhesives
