酚醛树脂改性脲醛树脂胶黏剂的研究进展

Research progress on phenol formaldehyde resin modified urea formaldehyde resin adhesives

脲醛树脂是一种氨基树脂类热固性合成树脂,是尿素和甲醛在碱性或酸性催化剂作用下,经加成反应、缩聚反应生成的缩聚物.脲醛树脂具有原料廉价易得、制造工艺简单,无色透明,对木质纤维素有优良的粘附力,是木材胶黏剂中用量最大的品种,约占木材液胶黏剂的80%以上,主要用于胶合板、刨花板、密度纤维板等的粘接.脲醛树脂胶黏剂有两个主要的缺点:游离甲醛释放和耐水性差,是脲醛树脂在实际生产应用中亟待解决的问题.酚醛树脂被广泛地用于提高脲醛树脂胶黏剂的耐水性及降低脲醛树脂胶黏剂的游离甲醛的含量.介绍了酚醛树脂对脲醛树脂胶黏剂的改性技术,综述了国内外酚醛树脂改性脲醛树脂胶黏剂的研究现状,并对其发展前景提出了展望.

Urea formaldehyde resin, a kind of thermosetting amino resin, was prepared by the reaction between urea and formaldehyde under alkaline or acidic catalyst. Urea-formaldehyde resin has been widely used as adhesives for wood-based panel such as plywood, particleboards and density fiberboards because of their excellent properties including low cost, fast curing, colorless and excellent adhesion to wood. Nevertheless,their main drawbacks are low water resistance and emission of formaldehyde from the wood panels, which are critical problems to be solved in actual application. Phenol formaldehyde resin(PF) has been widely used to improve the water resistance of urea formaldehyde resin(UF) and to reduce the formaldehyde content of UF adhesives. The modification technology of UF adhesives with PF was presented. Current research progress of PF modified UF adhesive was reviewed and the trends in the future were prospected.