Comparison of various water repellents for stability and durability improvement of urea formaldehyde-bonded particleboard

被引：0

作者：

Edoga, M.O. ^{[1
]}

Ebewele, R.O. ^{[1
]}

Anosike, R.N. ^{[1
]}

Kabir, M.G. ^{[1
]}

Mamze, P.A. ^{[1
]}

机构：

[1] Chemical Engineering Department, Federal University of Technology, Minna, Nigeria

来源：

Modelling, Measurement and Control C | 2001年 / 62卷 / 1-2期

关键词：

Adhesion - Aging of materials - Bonding - Hydrophobicity - Nuclear magnetic resonance spectroscopy - pH effects - Synthesis (chemical) - Urea formaldehyde resins - Water;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The chemical bonding involved in the fortification of urea-formaldehyde (UF) adhesives synthesized at F/U ratio 1.0, pH 1.0, and at 50°C for particleboard's manufacture have been investigated by infrared and liquid state 1HNMR nuclear magnetic resonance spectroscopy. Spectra were obtained for both neat sample and a number which had been formulated with water repellents. The use of artificial aging tests to model the fortification of UF-bonded particleboards was investigated. The particleboard samples were exposed continuously to controlled conditions of temperatures under both dry humid conditions for eleven cyclic wet-dry exposures. UF resins synthesized in acidic medium of pH 1.0, showed features in their spectra which are consistent with a tri-, and / or tetra-substituted urea in the reaction to give a 3-dimensional network cured UF resin. Formulation with PARA (paraffin wax), PEWA (pseudo ester wax), BEWA, (bee wax), prominently increased the absorbance of methylene in the spectra which are consistent with increased hydrophobicity. Moreover, resins formulated with water repellents showed significant improvement in the hydrolytic stability during the cyclic exposure. The neat resin (without any additive) was found to have higher susceptibility to degradation relative to the resins formulated with water repellents.

引用

页码：25 / 44