Polyurethanes in a sentence

Hydrogen cyanide may be produced in the combustion of polyurethanes ; for this reason, polyurethanes are not recommended for use in domestic and aircraft furniture.

Polyols used to make rigid polyurethanes have molecular weights in the hundreds, while those used to make flexible polyurethanes have molecular weights up to ten thousand or more.

While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.

All of these glycols form polyurethanes that phase separate well and form well defined hard segment domains, and are melt processable.

Both the isocyanates and polyols used to make polyurethanes contain, on average, two or more functional groups per molecule.

Despite them being complex mixtures, industrial grade polyols have their composition sufficiently well controlled to produce polyurethanes having consistent properties.

Polyester polyols are usually more expensive and more viscous than polyether polyols, but they make polyurethanes with better solvent, abrasion, and cut resistance.

Polyurethanes neither contain nor are produced from ethyl carbamate.

Production Polyurethanes are produced by mixing two or more liquid streams.

Some noteworthy recent efforts have been dedicated to minimizing the use of isocyanates to synthesize polyurethanes, because the isocyanates raise severe toxicity issues.

The choices available for the isocyanates and polyols, in addition to other additives and processing conditions allow polyurethanes to have the very wide range of properties that make them such widely used polymers.

The crosslinking present in polyurethanes means that the polymer consists of a three-dimensional network and molecular weight is very high.

They are all suitable for thermoplastic polyurethanes with the exception of ethylene glycol, since its derived bis-phenyl urethane undergoes unfavorable degradation at high hard segment levels.