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脲醛树脂化学结构及反应的13C-NMR研究(PDF)

《南京林业大学学报(自然科学版)》[ISSN:1000-2006/CN:32-1161/S]

Issue:
2006年05期
Page:
15-20
Column:
研究论文
publishdate:
2006-05-20

Article Info:/Info

Title:
A Study on Chemical Structure and Reaction of Urea-formaldehyde Resin by 13C-NMR Spectrometry
Article ID:
1000-2006(2006)05-0015-06
Author(s):
HAN Shu-guang WU Yu-fei
College of Wood Science and Technology Nanjing Forestry University, Nanjing 210037, China
Keywords:
UF resin Chemical shift Chemistry structure 13C-NMR
Classification number :
TQ433
DOI:
10.3969/j.jssn.1000-2006.2006.05.004
Document Code:
A
Abstract:
The very good method to analyze the structural change of reaction process of UF resin synthesized by the traditional process alkali-acid-alkali is 13C-NMR,and it may extrapolate the possible reaction. The structure analysis indicated that, under alkalinity condition, formaldehyde and urea reacted by addition reaction was primary. The reaction production was mainly monomethylolurea. The urea participated in the reaction completely. The formaldehyde this time still had existence by polymerization, at the same time had the occurrence of polycondensation reaction. At the acid reaction stage the polycondensation reaction was primary and formed the macro molecule system with the methylene or the ether linkage, and the polymerization formaldehyde decomposed completely, and as the form of methylene glycol participated in condensation reaction. The third urea joined may obviously reduce the free formaldehyde content of the reacting system, at the same time the reaction production was mainly monomethylolurea.

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Last Update: 2013-05-20