Abstract: Urea-formaldehyde (UF） resins were synthesized by the tradition method and the best ratio of formaldehyde and urea was 2. Modified UF were synthesized with different modifiers. With an increase of melamine and polyvinyl alcohol compounded modifiers’ dosage，the content of free formaldehyde and curing time decreased，the best dosage of the compounded modifiers was 8% and compressive strength of resin was 9.0 MPa. The best dosage of phenol modifier was 10%，compressive strength of resin was 14.2 MPa. The best dosage of furfural modifier was 15%，compressive strength of resin was 19.5 MPa. Melamine and polyvinyl alcohol compounded modifier decreased the content of free formaldehyde and curing time greatly，while compressive strength did not increase significantly；while modified UF resin with larger compressive strength could be prepared by using furfural modifier.

Key words: urea-formaldehyde resin, modification, synthesis, compressive strength

摘要： 采用传统方法合成了脲醛树脂，得出甲醛与尿素的最佳摩尔比为2。采用不同改性剂合成了改性脲醛树脂，得出：随三聚氰胺、聚乙烯醇复合改性剂用量的增加，树脂的游离甲醛含量、固化时间呈逐渐下降趋势，当复合改性剂用量为8%时树脂性能最佳，压缩强度为9.0 MPa；苯酚改性剂的最佳用量为10%，材料的压缩强度为14.2 MPa；糠醛改性剂的最佳用量为15%，材料的压缩强度为19.5 MPa；综合比较，三聚氰胺、聚乙烯醇复合改性剂可以明显降低游离甲醛的含量和固化时间，但材料的压缩强度增加不大，而采用糠醛改性剂制得改性脲醛树脂的压缩强度较大。

关键词: 脲醛树脂, 改性, 合成, 压缩强度