Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins, Part I: Structural and Physicochemical Properties
Journal Title: Leonardo Electronic Journal of Practices and Technologies - Year 2006, Vol 5, Issue 9
Abstract
First, phenol - formaldehyde (PF) and urea - formaldehyde (UFII) resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure). Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER) (i.e. UFIII) and glycerol (GLYC) (i.e. UFV) cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out. The results showed that the unmodified UF resin (UF II) synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, 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. Modification of the UF resin(UF II) with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I), the only clear distinction between spectra for the UF resin II and UF resins (III/V) is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V), cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL) showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.
Authors and Affiliations
Mathew EDOGA
Keywords
Related Articles
- EP ID EP139178
- DOI -
- Views 113
- Downloads 0
Design of an Alkaline Fuel Cell
This paper present the design of an alkaline fuel cell operating between 100-250oC. Hydrogen was bubbled into one arm while oxygen into the other. A meter was connected between the electrodes which detects the current f...
Determination of Contact Angle from Contact Area of Liquid Droplet Spreading on Solid Substrate
Both complete and incomplete wetting were considered for the spreading of liquid drops on solid substrate. The liquid droplets were silicone oil, glycerine and hexadecane and the solid substrates are glass, polystyrene a...
Evaluation of Causes of Retaining Wall Failure
Retaining structures are vital geotechnical structure, because the topography of the earth surface is a combination of plain, sloppy and undulating terrain. The retaining wall resists thrust of a bank of earth as well as...
Robust Controller Design for Speed Control of an Indirect Field Oriented Induction Machine Drive
The use of PI controllers for speed control of induction machine drives is characterized by an overshoot during tracking mode and a poor load disturbance rejection. This is mainly caused by the fact that the complexity o...
Effect of Water Quality on the Performance of Boiler in Nigerian Petroleum Industry
This work investigates quality of water used in boilers of Refinery Company in Nigeria. The results shows that the quality of water fed to boilers are off specification. Low water quality used in boilers led to frequent...