الفهرس 
basic information of organicOnly 14 pages are availabe for public view
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Abstract
The polyurethanes are a type of po~ers, obtained by ~teraotian and step-wise polymerization of an isocyanate compenent, and a hydroxyl-terminated po~ster/or polyether.
The nonoellular polyurethanes find appli.cations in the fJ.e~d of elastomers and surfaoe coatings.
he oellul.a.r j?olyurethanes aI’e colloidal systems con~1njng
a gas as the dispersed phase and the solid polymer as the een¬t1nuous pha.se
The types of the polyurethane foam” differ from one another in the degree of crosslinki.ng. Uncrossli.nk@d lineat’ polymer structure is found in the elastomeric foam. Slightly c:.roaslinked
polymer structure is found in the flexible foam. Moderately
crosslinked polymer structure is found in the semirigid foam,
and a highly crossl1nked pol~”lD.er structure is found in the rigid foam.
The flexible polyurethane foams are usually of an open-eell
strubture and are used as acoustic insulator and as a flexible
cushion foam. The rigid polyurethane foams are usua1ly of a closed-cell structure and are used as thermal insulator~ ~he semirigid foams are used mainly in the automotive industry, where shock absorbing and more elastic prope.cties are desired. The cellul.ar polyurethane elastomers are best regarded as more flexible and softer versions of the solid polyurethane products from which they are derived, and they are not really compat’able with the conventional. polyurethane foams. The eellular elasto-
mers find appl1.cations 1n the automobile industry as suspension