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- Polyurethanes : chemistry, technology, and applications
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The first polyols used for rigid polyurethane foams PUF were low-molecular weight MW polyesters based on adipic acid AA , phthalic anhydride and various glycols or polyols. One example of a polyester of this type is the polycondensation product between AA, phthalic anhydride and trimethylolpropane TMP [1—3]. Sometimes, this polyester is modified with oleic acid in order to improve its compatibility with blowing agents. The chemistry for the synthesis of rigid polyester polyols is absolutely the same as the chemistry for the synthesis of polyester polyols used in elastic polyurethane PU , described in detail in the Volume 1, Chapter 5. These polyester polyols were of minor importance and during the period —, they were replaced rapidly by low cost, low viscosity and high functionality polyether polyols, which lead to superior physico-mechanical properties of the resulting rigid PUF and superior miscibility with fluorocarbon blowing agents. The polyether polyols proved to be superior in rigid PUF fabrication, when the isocyanate index was low, approximately —
A detailed review of polyurethanes which describes the synthesis of raw materials, manufacturing technology and processing. The text describes the properties and applications of polyurethanes and includes coverage of the latest research and analytical methods. Read more Table of contents. Please choose whether or not you want other users to be able to see on your profile that this library is a favorite of yours. Finding libraries that hold this item You may have already requested this item.
Polyurethanes : chemistry, technology, and applications
Explore a new genre. Burn through a whole series in a weekend. Let Grammy award-winning narrators transform your commute. Broaden your horizons with anentire library, all your own. The main raw materials used for the production of polyurethanes are polyols, isocyanates and propylene oxide.
Polyurethanes PUs are a class of versatile materials with great potential for use in different applications, especially based on their structure—property relationships. Their specific mechanical, physical, biological, and chemical properties are attracting significant research attention to tailoring PUs for use in different applications. Enhancement of the properties and performance of PU-based materials may be achieved through changes to the production process or the raw materials used in their fabrication or via the use of advanced characterization techniques. Clearly, modification of the raw materials and production process through proper methods can produce PUs that are suitable for varied specific applications. The present study aims to shed light on the chemistry, types, and synthesis of different kinds of PUs.
Chemistry and Technology of Polyols for Polyurethanes Rapra Technology Limited Rapra Technology is the leading independent international organisation with.
Organic Polymer Chemistry pp Cite as. For the purposes of this chapter, polyurethanes are defined as polymers which contain urethane groups -NH-CO-O- in the main polymer chain. However, it is to be noted that in technologically useful polymers of this type the urethane group is not usually the principal group present; other groups such as ester, ether, amide and urea groups are generally contained in the polymer chain in appreciable number. Unable to display preview. Download preview PDF.
This first volume of the updated and extended 3rd edition of this work covers the basic chemistry and technology of oligo-polyol fabrication, the characteristics of the various oligo-polyol families and the effects of their structure on the properties of the resulting PU. This book is of interest to chemists and engineers in industry and academia as well as anyone working with polyols for the manufacture of PUs. Summarizes the basic chemistry of polyols and polyurethanes.
Polyurethanes are polymers prepared from the reaction between polyfunctional isocyanates and polyols, containing intramolecular urethane bonds. The thermosetting polyurethane PUR is a non-biodegradable polymer, that cannot be reprocessed by melting, so that the waste generated becomes an environmental problem. This study presented a viable alternative for the use and value aggregation of the thermoset polyurethane residue, contributing to minimize environmental impacts and to improve the properties of thermoplastic polyurethane. Bolsoni, E. Callister, J.
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