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THE POLYMER BOOKSHOP®
CD-Books & CD-Articles on Polymer Technology, Science & Marketing |
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| The Polymer Bookshop | CD-Books & CD-Articles in Word format |
Biopolymers |
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Biobased polyols for industrial polymers From chemistry to marketing ISBN: 9789078546276 |
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The inner CD-insert, which is shown below, exposes the contents of
the first edition of the book which will be available on CD-R, from November 2008. The CD-Book is on sale at the "Polymer Bookshop". The book is addressed to employees of companies involved in the manufacture, compounding and processing of polymers and polymer chemicals as well as to consultants, lecturers, academic researchers and students following a degree in polymer science and technology. ALL PUBLICATIONS ARE REVIEWED, UPDATED AND RE-EDITED A WEEK BEFORE SHIPMENT |
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| The outer CD insert of an edition of the CD-Book is exposed below |
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The pages appear on the PC screen as follows. The example below is not necessarily extracted from the latest edition. |
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To order the CD-Book (€ 45, payable by telebanking, VISA & MASTERCARD through PAYPAL, MoneyBookers etc.)please visit THE POLYMER BOOKSHOP or send us an email (info@gem-chem.net).. The "Advanced course" version, which does not include a literature survey, costs € 40. The "A Course" version, which is a comprehensive account of the subject, costs € 30. ALL PUBLICATIONS ARE REVIEWED, UPDATED AND RE-EDITED A WEEK TO 15 DAYS BEFORE SHIPMENT |
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The CD-book has been written by Dr Demosthenes Kyriacos,GEM-Chem, E-mail: dk@GEM-Chem.net, phone: +32-2-7710649 D.Kyriacos has worked at Upjohn, GE and ICI in international TS, Sales and Marketing. He holds a B.Sc.(Distinction, Honours, University award of Chemistry) from Alexandria, a M.Sc.course,(ICI scholarship award) in Polymer Technology and, a Ph.D. from Loughborough (UK). D. Kyriacos is the founder of DK Business Group and GEM-Chem. |
| Naturally POM |
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A-Introduction The origin of commercial thermoplastics, thermosets and elastomers is automatically linked to the petrochemicals industry. The main reason is that the source of the monomers, which constitute their building blocks, are derivatives of chemicals either isolated from the distillation of crude oil or obtained from the combustion of natural gas. Examples of such basic petrochemicals include aromatics as well as alkenes. | |||||
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B-POM from natural sources However among the engineering thermoplastics exceptions exist or, more precisely, they can be made to exist if some modifications are introduced to their production methods. In this article the polymer in question is polyacetal or polyoxymethylene (POM). As everybody knows, polyacetals are commercialised in two forms, the homopolymers, first developed by DuPont in the nineteenfifties and the copolymers which were marketed a few years later by Celanese and Hoechst through their joint venture, Ticona. The very basic difference between homopolymers and copolymers lies in the method used to stabilise the heat sensitive polyformals which are produced by the polymerisation of formaldehyde. A quick glance at the synthesis of polyacetal homopolymer, will give some insights on the possibilities of converting its current production to an environmentally friendly one. | |||||
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1-CH4
from natural gas is converted to syngas by steam reforming CH4 + H2O (steam) ---------> CO + 3H2 In this step natural gas is subjected to the effect of large quantities of energy for the sake of producing carbon monoxide and hydrogen. Letting aside nature and the financial interests involved in ripping it off, methane can also be generated from biomass. Microorganisms digesting buried organic waste produce landfill gas composed of methane (50-55%), carbon dioxide (40-45%), and trace levels of volatile organic compounds. At least the investments in such technologies will be beneficial to the environment. | |||||
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2-The syngas components are reacted in the presence of a catalyst (Cu/ZnO/Al2O3)at 50–100 atm and 250 °C to give methanol CO + 2H2 --------> CH3OH Hydrogen can be generated from the electrolysis of water. However the energy input required is tremendous and it can most advantageously be provided by nuclear power plants, which at the moment constitute the cleanest and most reliable source of bulk energy. On the other hand carbon dioxide, the whole world in not in short supply of, can be converted to carbon monoxide through the good old reduction reaction we have all been taught at the preparatory school. CO2 + H2 -------->CO + H2O The wonders of chemical engineering have provided us with methods of transforming carbon dioxide to methanol. CO2 + 3 H2 -------->CH3OH + H2O
3-Methanol is oxidised to formaldehyde (Formox or BASF processes for example) | CH3OH + ½ O2 --------> HCHO + H20 The oxygen required for this oxidation reaction can be conveniently obtained from the electrolysis of water H2O --------> H2 + 1/2 O2
4-Formaldehyde is polymerised anionically or cationically in a solvent (cyclohexane, toluene,...etc...)to a heat sensitive, hemiacetal terminated, polyacetal ( Mn = 20 000 to 100000) | HCHO + catalyst (R) ----Cyclohexane----> R(CH2O)n-CH2OH Unfortunately, this synthetic step includes a solvent, which is sourced from the petrochemicals industry. To discard the manufacturing routes which involve solvents scientists and engineers must solve the technical problems associated with the gas polymerisation of formaldehyde. The alternative of converting HCHO to trioxane,  , and polymerising the latter in bulk to polyacetal
avoids the use of a solvent. However the manufacture of trioxane itself involves a benzene
extraction process.
5-The hemiacetal end groups are stabilised by acetylation | R(CH2O)n-CH2OH + (CH3CO)2O ---CH3COONa------> R(CH2-O)n-CH2OCOCH3
6-Copolymers which involve the copolymerisation of trioxane with a small amount
of dioxolane or ethylene oxide, |  will be more difficult to manufacture in a green way since both monomers are
synthesised from ethyleneCH2=CH2+ 1/2O2--------> ethylene oxide---H2O----> HO-CH2-CH2-OH HO-CH2-CH2-OH + HCHO --------> dioxolane,  .The problem can be solved in an environmentally attractive way if ethylene can be isolated from a recycling process involving thermooxidation or cracking
C-Conclusions | A green method for the manufacture of POM hopolymers and copolymers can be achieved if -Methanol is produced in an environmentally friendly way from biomass or carbon dioxide and hydrogen. The technical problem to be solved is the gas phase polymerisation of formaldehyde unless the recycling of the polymerisation medium is not regarded as a sin the environment finds it difficult to forgive. Furthermore, formaldehyde can also be partly generated from the depolymerisation of polyacetals -Trioxane is isolated through methods other than extraction with benzene. Here again, by recycling benzene efficently, the damages caused to the environment are minimal -Ethylene, which is used in the manufacture of the comonomers is isolated from a cracking operation performed on polyolefins or some rubbers. -Energy is generated from clean sources, the most viable of which is, until now, of nuclear origin. April 2007. |
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This article has been written by Dr Demosthenes Kyriacos, President, GEM-Chem, E-mail: dk@GEM-Chem.net ; phone +32-2-7710649 D.Kyriacos has worked at Upjohn, GE and ICI in international TS, Sales and Marketing. He holds a B.Sc.(Distinction, Honours, University award of Chemistry) from Alexandria, a M.Sc.course,(ICI scholarship award) in Polymer Technology and, a Ph.D. from Loughborough (UK). D. Kyriacos is the founder of DK Business Group and GEM-Chem. |
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GEM-Chem compose and publish CD-books and CD-Articles on Polymer Science, Technology and Marketing. |
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GEM-Chem implement projects on company organisation, return to profitability, international marketing, technology and science. |
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