Underwater inspection of coastal structures using commercially available sonars / by William M. Kucharski, James E. Clausner ; prepared for Department of the Army, US Army Corps of Engineers.

Abstract

The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products.

Polyetherols from isocyanuric acid and ethylene carbonate

“…Instead, signals appear from methylene group protons in oxyethylene units at 3.9 and 3.45 ppm from ϾNOCH 2 O and OCH 2 OOO, respectively. 5 The signal from terminal methylene groups in the oxyethylene chains OCH 2 OH was found to appear at 4.3 ppm. The compositions of some polyetherols prepared in this work, as calculated from 1 H-NMR spectra, are presented in Table III. The structures of polyetherols, represented by Scheme 1, are further confirmed by IR spectra, where characteristic bands are present, such as those due to valency at ca.…”

“…The reason was that, as shown in ref. 5, the desired resinous products, not containing the lowmolecular solid N-2-hydroxyethyl derivatives of IA, can be obtained at an IA/oxirane molar ratio of 1:Ͼ 5.…”

“…An alternative method of preparing polyetherols from isocyanuric acid was described some time ago. 5,6 The method consists of reacting the acid with formaldehyde to obtain N,NЈ,NЉ-tris(hydroxymethyl) isocyanurate (THMI). The latter dissolves well in oxiranes in the presence of a small amount of water, and hence no additional solvents are needed.…”

Water-soluble sulfonated melamine–oxytriazine resins: Synthesis and properties as dispersants

“…The reactions taking place in step 4 are not well understood. The conditions are, however, appropriate for methylene-linkage type condensation [reaction (9)]. It appears that some of the condensation linkages formed during the previous step break up or rearrange as evidenced by the sharp reduction in viscosity which occurs immediately following the addition of base.…”