苯酚-尿素-甲醛共缩聚树脂结构与胶接性能关系研究

【作者】 范东斌； 刁艳； 李建章； 方艳平； 卢虹；

【Author】 FAN Dong-bin;DIAO Yan;LI Jian-zhang;FANG Yan-ping;LU Hong.Study on the Structure and Properties of Phenol-Urea-Formaldehyde cocondensed resins.College of Material Science and Technology,Beijing Key Laboratory of Wood Science and Engineering,Key Laboratory of Wooden Material Science and Application,Ministry of Education,Beijing Forestry University,100083,P.R.China.

【机构】 北京林业大学材料科学与技术学院,木材科学与工程北京市重点实验室,木质材料科学与应用教育部重点实验室；

【摘要】 在树脂反应初期和后期分别添加尿素合成了苯酚-尿素-甲醛（PUF）共缩聚树脂。通过PUF树脂的胶合板制备实验,研究了反应后期尿素的添加量及热压温度对胶合板胶合强度的影响;使用¹³C核磁分析(¹³C-NMR)对不同尿素添加量的PUF树脂的微观结构进行表征,探讨了树脂结构与胶合板胶合强度之间的关系。结果表明:在PUF树脂的合成后期加入的尿素参与了树脂的共缩聚反应;当尿素添加量为89.4%,热压温度为150℃时,PUF树脂胶接胶合板符合I类胶合板标准要求;PUF树脂中低分子的取代脲以及羟甲基脲共同影响着PUF树脂固化后的物理性能。更多还原

【Abstract】 Phenol-urea-formaldehyde cocondensed（PUF） resins were synthesized by adding urea at the former and end of the condensation reaction,respectively.The effect of amounts of urea added at the end of the condensation reaction and hot-press temperature on plywood bonding strength were investigated by preparing the PUF-bonded plywood.Microcosmic structure of PUF resins with different urea content was analyzed by liquid ¹³C nuclear magnetic resonance（NMR）.And the relations between microcosmic structure and plywood bonding strength were also discussed. Results showed that urea which was added at the end of the condensation reaction,can take part in the condensation reaction of PUF resins.When amount of urea addition reached 89.4%（W_U/W_P） and hot-press temperature was 150℃,the plywood bonded by the PUF resin can pass the GB/T minimum wet strength value for the exterior grade of structural plywood.Low molecule substituted urea and methylolurea in PUF resins together influenced the physical performance of cured resin.更多还原