高等学校化学学报

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酸性条件下脲醛树脂中不稳定结构的研究

李爱萍, 阚成友, 杜奕, 刘德山   

  1. 清华大学化工系高分子研究所, 教育部先进材料重点实验室, 北京 100084
  • 收稿日期:2005-12-12 修回日期:1900-01-01 出版日期:2006-09-10 发布日期:2006-09-10
  • 通讯作者: 刘德山

Studies on Unstable Structures in Urea\-ormaldehyde Resins Prepared in Strong Acid Medium

LI Ai-Ping, KAN Cheng-You, DU Yi, LIU De-Shan   

  1. Institute of Polymer, Department of Chemical Engineering, Key Laboratory of Advanced Materials of Ministry of Education, Tsinghua University, Beijing 100084, China
  • Received:2005-12-12 Revised:1900-01-01 Online:2006-09-10 Published:2006-09-10
  • Contact: LIU De-Shan

摘要:

通过较强酸性介质中尿素和甲醛的反应, 在不同条件下合成了透明的脲醛树脂溶液, 利用液体13C NMR研究了甲醛与尿素摩尔比对最终树脂中不稳定结构的影响.

关键词: 脲醛树脂, 不稳定结构, 13C NMR, 摩尔比

Abstract: The variations of unstable structures in the synthesized urea-formaldehyde (UF) resin systems with the change of the molar ratios of formaldehyde to urea were discussed by 13C NMR spectroscopy. The results show that the relative contents of dimethylene ether groups, methylols and unreactive formaldehyde increased gradually with the increase of the molar ratios of formaldehyde to urea from 0.5 to 3.0, which implied that the structure of UF resins can be optimized by controlling the molar ratios of formaldehyde to urea in the process of synthesizing UF resin. It is optimal for the molar ratios of formaldehyde to urea in the range of 1.5 to 2.0, as evidenced by small amounts of unstable structures and significant amounts of stable structures in UF resins prepared.

Key words: Urea-formaldehyde resin, Unstable structure, 13C NMR, Molar ratio

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