Magazine article from our research archive:
Abstract
Polyurethanes are obtained by reacting polyols with polyisocyanates. The primary hydroxyl content is a very important characteristic of polyols because it affects their reactivity. Typically primary hydroxyls are approximately threefold more reactive than the secondary hydroxyls when reacting with aromatic isocyanates. This paper presents a simple and convenient kinetic method for determining the primary hydroxyl content in soybean polyols, based on the difference in reactivity of primary and secondary hydroxyls with phenyl isocyanate (PI). The reaction kinetics were studied by following the disappearance of the NCO band at 2260 cm^sup -1^ with time in the infrared spectra. The ...
|
polyhydric alcohol
A Dictionary of Chemistry;
13 words
...polyhydric alcohol (polyol) An alcohol that has several hydroxyl groups per molecule.
|
|
|
diol
A Dictionary of Chemistry;
12 words
...diol (dihydric alcohol) An alcohol containing two hydroxyl groups per molecule.
|
|
Mechanical properties of hand-cast and reaction injection molded...
Polymer Engineering and Science;
February 1, 1997 ;
Fan, Lian Hua Hu, Chun Pu Ying, Sheng Kang;
787 words
......product. As VER is possessed of pendent hydroxyl groups on its backbone, the inter-component...is greatly affected by the pendent hydroxyl groups existing in VER (14, 15). Consequently...In this study, VER with its pendent hydroxyl groups retained or capped were synthesized...
|
|
dihydric
The Oxford American College Dictionary;
31 words
...di·hy·dric / dīˈhīdrik / • adj. Chemistry (of an alcohol) containing two hydroxyl groups. ORIGIN: late 19th cent. : from di- 1 ‘two’ + hydrogen + -ic .
|
|
|
trihydric
The Oxford American College Dictionary;
32 words
...tri·hy·dric / trīˈhīdrik / • adj. Chemistry (of an alcohol) containing three hydroxyl groups. ORIGIN: mid 19th cent. : from tri- ‘three’ + hydrogen + -ic .
|
|
triol
Webster's NewWorld Dictionary;
27 words
...Webster's NewWorld Dictionary 01-01-1988 tri|ol (tri'ol, -ol) n. a compound with three hydroxyl groups in the molecule Copyright 1994, 1991, 1988 Simon & Schuster, Inc.
|
|
|
glyceride
A Dictionary of Chemistry;
71 words
......glycerol. Esterification can occur at one, two, or all three hydroxyl groups of the glycerol molecule producing mono-, di-, and triglycerides...oils found in living organisms. Alternatively, one of the hydroxyl groups may be esterified with a phosphate group forming a phosphoglyceride...
|
|
|
trihydroxy
Webster's NewWorld Dictionary;
25 words
...Webster's NewWorld Dictionary 01-01-1988 tri|hy|drox|y (tri|hi drks'e) adj. containing three hydroxyl groups Copyright 1994, 1991, 1988 Simon & Schuster, Inc.
|
|
Tribochemistry of Fluorinated Fluids Hydroxyl Groups on Steel and Aluminum...
Tribology Transactions;
April 1, 2006 ;
Przedlacki, Marcin; Kajdas, Czeslaw;
787 words
......compound to study the reactions of hydroxyl groups. Tribochemical reactions were initiated...fluorinated compounds containing hydroxyl groups formed carboxylic and alkoxyl salts...tribochemistry of Z-Dol, including two end hydroxyl groups, and a model compound with one hydroxyl...
|
|
The chemistry of anthocyanins
Functional Foods & Nutraceuticals;
July 1, 2005 ;
Galvano, Fabio;
787 words
......anthocyanins differ in the number of hydroxyl groups present in the molecule; the degree of methylation of these hydroxyl groups; the nature, number and location...differing both in the number of hydroxyl groups present on the carbon ring...
|
|
Excimer laser achieves better Teflon bonding
High Performance Plastics;
June 1, 1994 ;
98 words
......extract fluorine molecules from the Teflon surface which are replaced by hydroxyl groups from laser beam decomposition of boric acid. The replaced hydroxyl groups form chemical bonds with underlying adhesives. Epoxy resin was used in trials...
|
|
Oregon, Wisconsin Inventors Develop Modified Peptides Synthesis Method
US Fed News Service, Including US State News;
November 29, 2007 ;
438 words
......modified at one or more side-chain hydroxyl groups. Azide-bearing protecting groups allow...selective deprotection of side-chain hydroxyl groups of amino acids after synthesis of...employed in peptide synthesis, such that hydroxyl groups protected with the azide-bearing protecting...
|
|
Chemical modification of cellulose membranes with improved blood...
Biomedical Materials;
February 1, 1992 ;
161 words
......polysaccharide structure of cellulose with the special arrangement of hydroxyl groups at the anhydroglucose unit can be postulated as a trigger for activation. The hydroxyl groups localized at the surface of the membrane were masked in this study...
|
|
|
POLYOL FOR ELASTOMERS, COATINGS AND ADHESIVES.
High Performance Plastics;
February 1, 2001 ;
156 words
......trimethylolpropane (TMP) polyol containing 100% secondary hydroxyl groups. It is used primarily in elastomer, coating and adhesive...TMP) polyol, Poly-G 35-610, that contains 100% primary hydroxyl groups and can also be used in elastomers, coatings and adhesives...
|
|
|
California Inventors Develop Fiber Reinforced Cement Composite Material
US Fed News Service, Including US State News;
April 7, 2008 ;
364 words
......surface more hydrophobic. The dispersant inhibits the hydroxyl groups on the cellulose fiber surface from bonding with hydroxyl groups of other fibers and from bonding with hydroxyl groups of the same fiber, thereby significantly reducing...
|
See all results.
Or, try our
Advanced Search.
|