毕业论文：三聚氰胺改性脲醛树脂的研究.doc

三聚氰胺改性脲醛树脂的研究
Study on Performance of Modified Urea-Formaldehyde Resin
目录
摘要 Ⅰ
Abstract II
引言 1
第一章绪论 2
、甲醛、三聚氰胺产品概述 2
2
脲醛树脂合成中的问题 3
3
3
4
4
6
6
6
6
6
6
研究意义和内容 7
研究意义 7
研究内容 7
第二章实验部分 8
脲醛树脂的合成 8
合成机理 8
10
实验方法 10
第三章结果与讨论 13
实验结果与分析 13
13
14
16
,用乙酸作为酸性催化剂下的热失重图 16
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18
结论 20
致谢 21
参考文献 22
三聚氰胺改性脲醛树脂胶黏剂的研究
摘要:脲醛树脂胶黏剂具有价格便宜、固化速度快、粘结力好、制造方便等优点,但也存在游离甲醛含量高的问题,对人体造成危害。本文在温度、反应过程等条件不变的情况下,用不同甲醛(F)和尿素(U)的摩尔比,加成阶段PH值,三聚氰胺占尿素的比例三个因素对合成的脲醛树脂(UF)胶黏剂性能进行了工艺优化。在不加聚乙烯醇等改性剂的情况下,通过三聚氰胺对脲醛树脂进行改性,以达到降低胶黏剂中游离甲醛含量的目的。结果表明:随着F与U摩尔比的升高,脲醛树脂中游离甲醛含量明显升高;,-,三聚氰胺加入量占尿素的2%时是最优条件;通过正交试验优化后甲醛释放量明显降低,粘度变化适中。当缩聚反应阶段用甲酸替换乙酸时,脲醛树脂中的游离甲醛含量继续降低,粘度变化适中。
关键词:脲醛树脂; 游离甲醛; 三聚氰胺; 共聚改性

Study on Performance of Modified Urea-Formaldehyde Resin
Abstract: The urea-formaldehy resin adhesive had a lot of good points such as cheap price, solidifty rapidity, high bonding strength, compounding easy, . There were also some problems just like high dissociated formaldehyde, which made harm to people. It was used different formaldehyde (F) and urea (U) mole ratio, addition phase pH value, melamine accounted for the proportion of urea on synthesis of urea-formaldehyde resin (UF) adhesive performance to optimize the process under the constant temperature and reaction process. The paper modified urea-formaldehyde resin by melamine .in order to reduce the free formaldehyde content in the adhesives under the case of without PVA. The experimental results show that content of the free formaldehyde resin as the rise and rise of the F and U mole ratio in the UF; The optimal conditions was the formaldehyde and urea mole ratio to , addition phase pH