UF树脂和MF树脂共混特性研究

为研究脲醛树脂（UF）和三聚氰胺甲醛树脂（MF）及其共混树脂（MF+UF）的贮存特性，采用“碱-酸-碱”工艺分别合成了UF树脂和MF树脂，其摩尔比分别为1.3和2.0。将制备好的UF和MF树脂进行简单搅拌共混，得到MF+UF树脂，监测共混前后树脂及在贮存一段时间后的性能变化，如外观形态、pH值、黏度、固化时间及结构等性能。结果表明，共混后树脂的固含量介于UF和MF之间；稳定性明显提升，贮存期可达3个月，固化速度则无明显差异；核磁共振图谱（NMR）分析得出，共混树脂中的亚甲基桥键比例提高至24.13%，亚甲基醚键比例则下降至25.03%，这种结构比例的变化为共混树脂稳定性的提高提供了理论支撑。

Blend Characteristics of MF+UF Resin Mixture

Urea-formaldehyde (UF) resin and melamine-formaldehyde (MF) resin were synthesized by “alkaline-acid-alkaline” process with molar ratios of 1.3 and 2.0,respectively,to investigate the storage behaviors of mixed UF and MF resin.The mixture MF+UF resin was prepared by simple mechanical blending method,the performances of the resin were evaluated during the storage,such as color,pH,viscosity and curing time,and the structure.The results showed that the solid content of blended resin maintained in between the solid content of UF and MF resin；the stability increased with significantly prolonged storage life (3 months).No significant difference in curing speed was found.The proportion of methylene bridge bond in the blended resin increased to 24.13%,while the proportion of methylene ether bond decreased to 25.03% by the NMR interpretation.The structure change would provide theoretical support for longer storage time of blended MF+UF resin.