我们的网站为什么显示成这样?

可能因为您的浏览器不支持样式,您可以更新您的浏览器到最新版本,以获取对此功能的支持,访问下面的网站,获取关于浏览器的信息:

|Table of Contents|

聚乙烯醇改性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:
2007年03期
Page:
78-82
Column:
研究论文
publishdate:
2007-03-20

Article Info:/Info

Title:
13C--NMR Spectrometry Study on Chemistry Structure and Reaction of Polyvinyl Alcohol Modified Urea-formaldehyde Resin
Article ID:
1000-2006(2007)03-0078-05
Author(s):
HAN Shu-guang WU Yu-fei
College of Wood Science and Technology Nanjing Porestr2 University, Nanjing 210037, China
Keywords:
UF resin Polyvinyl alcohol Chemical shift Chemistry structure 13C--NMR
Classification number :
TS727+.5
DOI:
10.3969/j.jssn.1000-2006.2007.03.016
Document Code:
A
Abstract:
The very good method to analyze the structural change of reaction process of polyvinyl alcohol modified UF resin by the traditional process alkali-acid-alkali is 13 C--NMR, and which extrapolate a possibly reaction. The structure analysis indicated that, under alkalinity condition, addition reaction was primary, reaction production was mainly monomethylolurea, the urea participated in the reaction completely, the formaldehyde was still in existence by polymerization, at the same time polycondensation reaction also happened. At a acid reaction stage, the polycondensation reaction was primary, the macro-molecule system was formed with the methylene or the ether linkage, the polymerization formaldehyde decomposed completely, and as the form of methylene glycol participated in condensation reaction. The third urea ioined might obviously reduce the free formaldehyde content of the reacting system, the reaction production was mainly monomethylolurea. The polyvinyl alcohol monomer chemical constitution had the good attribute on 13C--NMR, but the chemical shift that proved the polyvinyl formal didn’t examine, therefore in this experiment, the polyvinyl formal hasn’t been product.

References

-

Last Update: 2013-05-20