Poliemeros

1

Exercises From polymers to plastics
A.K. van der Vegt

DUP Blue Print

2

© VSSD DUP Blue Print is an imprint of: Delft University Press P.O. Box 98, 2600 MG Delft, The Netherlands tel. +31 15 27 85678, telefax +31 15 27 85706, e-mail info@library.tudelft.nl internet: http://www.library.tudelft.nl/dup Published on behalf of: Vereniging voor Studie- en Studentenbelangen te DelftPoortlandplein 6, 2628 BM Delft, The Netherlands tel. +31 15 27 82124, telefax +31 15 27 87585, e-mail: hlf@vssd.nl internet: http://www.vssd.nl/hlf URL on this book: http://www.vssd.nl/hlf/m008.htm A collection of digital pictures, printed in the book, can be made available for lecturers who adopt this book. Please send an e-mail to hlf@vssd.nl. All rights reserved. No part of this publication may bereproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photo-copying, recording, or otherwise, without the prior written permission of the publisher. NUGI 831 Key word: polymers

4

Contents
1. 2. 3. 4. 5. 6. 7. 8. 9. INTRODUCTION MOLECULAR COMPOSITION GLASSY STATE AND GLASS-RUBBER TRANSITION CRYSTALLINE POLYMERS RUBBERY AND LIQUIDPHASES VISCO-ELASTICITY MECHANICAL PROPERTIES FURTHER PROPERTIES POLYMERIC COMPOUNDS AND COMPOSITES 5 7 13 15 19 23 26 30 32 36 41 41 44 52 56 63 67 73 78 81 86

11. PRINCIPLES OF PROCESSING ANSWERS 1. Introduction 2. Molecular composition 3. Glassy state and glass-rubber transition 4. Crystalline polymers 5. Rubbertoestand en vloeibare toestand 6. Visco-elasticity 7. Mechanical properties 8.Further properties 9. Polymeric compounds and composites 11. Processing techniques

5

1
Introduction
1.1. Give twenty high molecular materials from a natural (both from vegetable and animal) origin, that are used as technical materials 1.2. Give ten technically used materials based on ‘half synthetic’ polymers and explain the addition ‘half’ to it. 1.3. Why are hydrocarbons, obtained from acracking process, very suitable for the production of synthetic polymers? 1.4. Why are polymers, built up from dienes, very suitable for application as technical rubbers? 1.5. Which kind of chainstructures can be formed in the polymerisation of butadiene (CH2 =CH–CH=CH 2 )? 1.6. Why is it not possible to vulcanise ethylene-propylene copolymers and polyisobutylene in the usual way. In what way arethese polymers modified in order to make vulcanisation possible anyway? 1.7. In what way can polymers be formed from saturated monomers? 1.8. In which two manners can a three dimensional network be formed? 1.9. What is the meaning of the name ‘thermosets’? Why can this name lead to misunderstanding? 1.10. What is the difference between thermoplastics on the one side and thermosets and rubbers on theother side? 1.11. What is the difference between thermosets and technical rubbers? 1.12. What is the difference between thermoplastic rubbers and ordinary rubbers? 1.13. What is the difference between thermoplastic rubbers and thermoplastics? 1.14. Give the most important thermoplastics, thermosets and synthetic rubbers. 1.15. Give the three maintypes of PE. What are the differences between thesetypes. 1.16. Give a number of polymers (thermoplastics, thermosets and rubbers) in which

6

Problems Polymers

styrene plays a role. 1.17. Which polymer cannot be manufactured to an end product in a normal production process? In what way is this polymer being processed? Which similar polymers are more suitable for production processes? 1.18. Give a polymer with an extremely high temperatureresistance and some members of the same family. 1.19. Give a number of composite plastics 1.20. When and for what purpose are the following materials added to a polymer? a. fine carbon black d. plasticizer g. lubricants j. wood flour m. UV-stabilisers b. chalk e. mica h. sulphur k. anti-oxidants n. antistatic agents c. glassfibres f. accelerators i. pentane l. silicium carbide o. rubber...