File Name: polyurethane and related foams chemistry and technology .zip
Introduction to polymers 2. Polyurethane foam chemistry 3. Recycling techniques 4.
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.
Oligoetherols based on pyrimidine ring were obtained upon reaction of barbituric acid with glycidol and alkylene carbonates. These oligoetherols were then used to obtain polyurethane foams in the reaction of oligoetherols with isocyanates and water. The protocol of foam synthesis was optimized by the choice of proper kind of oligoetherol and synthetic composition. The thermal resistance was studied by dynamic and static methods with concomitant monitoring of compressive strength. The polyurethane foams have similar physical properties as the classic ones except their enhanced thermal resistance. Moreover thermal exposition of foams results generally in increase of their compressive strength. Frisch, K.
While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available. Polyurethane polymers are traditionally and most commonly formed by reacting a di- or triisocyanate with a polyol. Since polyurethanes contain two types of monomers, which polymerise one after the other, they are classed as alternating copolymers. Both the isocyanates and polyols used to make polyurethanes contain, on average, two or more functional groups per molecule. Polyurethanes are used in the manufacture of high-resilience foam seating, rigid foam insulation panels, microcellular foam seals and gaskets , spray foam , durable elastomeric wheels and tires such as roller coaster , escalator , shopping cart , elevator , and skateboard wheels , automotive suspension bushings , electrical potting compounds, high-performance adhesives , surface coatings and sealants, synthetic fibers e.
Published by Iliffe Books, London Seller Rating:. About this Item: Iliffe Books, London, Condition: Good. Tightly bound. Corners not bumped.
Currently, one of the most serious environmental problems is water contamination by oil spills. The use of sorbents is considered one of the most promising approaches to treat this problem. In this study, polyurethane foam PUF was used as basal body material and chitin was used as a filler to decrease the cost of the sorbent PPU10M. The technological parameters of the synthesis process and a heat resistance of the new sorbent were investigated.
Polyurethanes are linear polymers that have a molecular backbone containing carbamate groups -NHCO2. These groups, called urethane, are produced through a chemical reaction between a diisocyanate and a polyol. First developed in late s, polyurethanes are some of the most versatile polymers. They are used in building insulation, surface coatings, adhesives, solid plastics, and athletic apparel.
Government works Printed in the United States of America on acidfree paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number Hardcover International Standard Book Number Hardcover This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the conse quences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers.
Это резиновая капсула, которая при попадании растворяется. Все тихо и чисто. Перед сердечным приступом мистер Танкадо не почувствовал ничего, кроме легкого укола. - Травматическая пуля, - задумчиво повторил Беккер. - Вот откуда шрам.
В руке Хейл сжимал беретту. Вскрикнув, она оторвала взгляд от неестественно выгнутой руки и посмотрела ему в лицо. То, что она увидела, казалось неправдоподобным. Половина лица Хейла была залита кровью, на ковре расплылось темное пятно. Сьюзан отпрянула.
Агент Смит! - позвал Фонтейн. Из-за спины Беккера появилось лицо Смита. - Слушаю, сэр.
Your email address will not be published. Required fields are marked *