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温度和固含量对脲醛树脂预固化行为的影响(PDF/HTML)

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

Issue:
2017年03期
Page:
145-150
Column:
研究论文
publishdate:
2017-05-31

Article Info:/Info

Title:
Effects of temperature and solid content on the pre-curing behavior of urea-formaldehyde resin
Article ID:
1000-2006(2017)03-0145-06
Author(s):
CHEN Yuzhu LI Jing LIU Fang XIE Lei XIAO Hui*
College of Forestry, Sichuan Agricultural University, Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Agricultural University, Chengdu 611130, China
Keywords:
pre-curing urea-formaldehyde resin temperature solid content molecular weight distribution chemical structure
Classification number :
TQ433
DOI:
10.3969/j.issn.1000-2006.200607036
Document Code:
-
Abstract:
【Objective】Temperature and solid content significantly influence the molecular weight and chemical structure of pre-curing urea formaldehyde resins, playing an important role in regulating pre-curing behavior.【Method】Gel chromatography(GPC)and 13C-NMR were used to investigate the effects of temperature and solid content on the molecular weight distribution and main functional groups of pre-curing urea-formaldehyde resins, as well as the relative amounts of methylol, dimethylene and dimethylene ether groups. 【Result】At constant pre-curing time, Mn and Mw increased with increasing curing temperature, with the content of dimethylene ethers initially increasing and then decreasing, whereas the content of terminal and linear methylol groups decreased and that of linear and network dimethylene groups increased. The molecular weight of higher-solid-content resins was higher than that of lower-solid-content ones, with insignificant differences observed between the former resins. Although the content of linear methylol, dimethylene and dimethylene ether groups slightly increased with increasing solid content, the total number of terminal methylol groups was unchanged. 【Conclusion】Temperature had a much more significant effect on the pre-curing of urea-formaldehyde resins than their solid content, as determined by comparing the contents of methylol, dimethylene, and ether functional groups.

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Last Update: 2017-05-20