In one-shot, the isocyanate, polyester or polyether resin, catalyst, and other additives are mixed directly and a foam is produced immediately.

Common polyether diols are polyethylene glycol, polypropylene glycol, and poly ( tetramethylene ether ) glycol.

The most common polymers in membrane synthesis are cellulose acetate, Nitrocellulose, and cellulose esters ( CA, CN, and CE ), polysulfone ( PS ), polyether sulfone ( PES ), polyacrilonitrile ( PAN ), polyamide, polyimide, polyethylene and polypropylene ( PE and PP ), polytetrafluoroethylene ( PTFE ), polyvinylidene fluoride ( PVDF ), polyvinylchloride ( PVC ).

The hydroxyl group in the tri-epoxide is activated as a nucleophile by the presence of the base caesium carbonate The bulky trimethylsilyl groups make such that the polyether is formed with the correct stereochemistry and they are removed in situ by caesium fluoride.

Polymerization of an epoxide gives a polyether, for example ethylene oxide polymerizes to give polyethylene glycol, also known as polyethylene oxide.

It is possible that the polyether foams may soon be molded on a production basis in low-cost molds with more intricate contours and with superior properties to latex foam.

Polyethylene glycol ( PEG ) is a polyether compound with many applications from industrial manufacturing to medicine.

It is used as an initiator of an anionic addition polymerization with ethylene oxide, forming a polyether with high molecular weight.

SABIC is also the world ’ s largest producer of mono-ethylene glycol, MTBE, granular urea, polyphenylene and polyether imide.

An example of an oxirane cascade reaction is given by the synthesis of certain polyether ladder polymers:

Chemically it is a polyether.

Although the first polyether foams on the market had to be produced by the two-step prepolymer method, today, thanks to new catalysts, they can be produced by a one-shot technique.

the polyether group generally consists of foams produced with polypropylene glycol or polypropylene glycol modified with a triol.

Satisfactory methods for polyester foams and even prepolymer polyether foams were never fully achieved.

The introduction of one-shot polyether foam systems, aided by the development of new catalysts, helped to alleviate some of the problems of closed molding.

They recognized that using the polyaddition principle to produce polyurethanes from liquid diisocyanates and liquid polyether or polyester diols seemed to point to special opportunities, especially when compared to already existing plastics that were made by polymerizing olefins, or by polycondensation.

The first commercially available polyether polyol, poly ( tetramethylene ether ) glycol, was introduced by DuPont in 1956 by polymerizing tetrahydrofuran.

As the decade progressed, the availability of chlorofluoroalkane blowing agents, inexpensive polyether polyols, and methylene diphenyl diisocyanate ( MDI ) heralded the development and use of polyurethane rigid foams as high performance insulation materials.

The denticity of the polyether influences the affinity of the crown ether for various cations.

A primary amino group (- NH < sub > 2 </ sub >) often functions as the starting point for two polymeric chains, especially in the case of polyether polyols.

PEGs and methoxypolyethylene glycols are manufactured by Dow Chemical under the tradename Carbowax for industrial use, and Carbowax Sentry for food and pharmaceutical use.

The olefins are used as feedstocks for derivative units that produce plastics ( polyethylene and polypropylene for example ), synthetic fiber precursors ( acrylonitrile ), industrial chemicals ( glycols for instance ) while the aromatics are used for octane boosting in fuel blending as well as polyethylene terephthalate PET feedstock and paint and coating solvents.

Another class of base oils suited for engine oil are the polyalkylene glycols.

Although glycols are effective air disinfectants in controlled laboratory environments, it is more difficult to use them effectively in real-world environments because the disinfection of air is sensitive to continuous action.

Continuous action in real-world environments with outside air exchanges at door, HVAC, and window interfaces, and in the presence of materials that adsorb and remove glycols from the air, poses engineering challenges that are not critical for surface disinfection.

These compounds are called glycols.

Alternative substances ( urea, alcohols, glycols ) are often used at airports.

Conventional cryoprotectants are glycols ( alcohols containing at least two hydroxyl groups ), such as ethylene glycol, propylene glycol, and glycerol.

Leblond had shown in earlier studies that the Golgi region in most cell types was dramatically stained by the periodic acid-Schiff staining technique, which is specially directed to carbohydrate-rich proteins carrying 1, 2 glycols.

However, charcoal is ineffective against metals such as sodium, potassium, and lithium, and alcohols and glycols ; it is also not recommended for ingestion of corrosive chemicals such as acids and alkalis.

This coolant is usually water-based, with the addition of glycols to prevent freezing and other additives to limit corrosion, erosion and cavitation.

In 1855, reviewing the various substances that had been obtained from glycerin, he reached the conclusion that glycerin is a body of alcoholic nature formed on the type of three molecules of water, as common alcohol is on that of one, and was thus led ( 1856 ) to the discovery of the glycols or diatonic alcohols, bodies similarly related to the double water type.

For water, the term is hydrolysis ; for alcohols, it is alcoholysis ; for ammonia, it is ammonolysis ; for glycols, glycolysis ; for amines, aminolysis.

This is suitable for cleaving glycols and alpha-hydroxy ketones in ring opening and Mannich reaction.

" The open time of an oil or alkyd-based emulsion paint can be extended by adding white spirit, similar glycols such as Dowanol ( propylene glycol ether ) or open time prolongers.

Less expensive polyalkylene glycols were introduced by BASF and Dow Chemical in 1957.

* Charles-Adolphe Wurtz discovers the glycols.

In the 1940s and early 1950s, further studies showed inactivation of diverse bacteria, influenza virus, and Penicillium chrysogenum ( previously P. notatum ) mold fungus using various glycols, principally propylene glycol and triethylene glycol.

The lubricative fluid contains water, pyridine, squalene, urea, acetic acid, lactic acid, complex alcohols and glycols, ketones, and aldehydes.

The oxidation of the glycols led him to homologues of lactic acid, and a controversy about the constitution of the latter with Adolph Wilhelm Hermann Kolbe resulted in the discovery of many new facts and in a better understanding of the relations between the oxy-and the amido-acids.

De-icing can be accomplished by mechanical methods ( scraping, pushing ); through the application of heat ; by use of dry or liquid chemicals designed to lower the freezing point of water ( various salts or brines, alcohols, glycols ); or by a combination of these different techniques.

These substances include small amounts of chemicals such as acetone, acetaldehyde, and other higher alcohols, esters, and aldehydes ( e. g. propanol, glycols, ethyl acetate ).