Modern Polyesters

Modern Polyesters
Author :
Publisher : John Wiley & Sons
Total Pages : 784
Release :
ISBN-10 : 9780470090671
ISBN-13 : 0470090677
Rating : 4/5 (71 Downloads)

Book Synopsis Modern Polyesters by : John Scheirs

Download or read book Modern Polyesters written by John Scheirs and published by John Wiley & Sons. This book was released on 2005-09-01 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides an overview of the family of polyester polymers which comprise an important group of plastics that span the range of commodity polymers to engineering resins. It describes the preparation, properties and applications of polyesters. Readers will also find details on polyester-based elastomers, biodegradable aliphatic polyester, liquid crystal polyesters and unsaturated polyesters for glass-reinforced composites. Presents an overview of the most recent developments. Explores synthesis, catalysts, processes, properties and applications. Looks at emerging polyester materials as well as existing ones. Written by foremost experts from both academia and industry, ensuring that both fundamentals and practical applications are covered.

Modern Styrenic Polymers

Modern Styrenic Polymers
Author :
Publisher : John Wiley & Sons
Total Pages : 796
Release :
ISBN-10 : 0471497525
ISBN-13 : 9780471497523
Rating : 4/5 (25 Downloads)

Book Synopsis Modern Styrenic Polymers by : John Scheirs

Download or read book Modern Styrenic Polymers written by John Scheirs and published by John Wiley & Sons. This book was released on 2003-03-28 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title addresses the latest developments in the field, covering the major advances that have occurred over the past five years in the polymerization and structure of new generation polystyrenes that are broadening its scope of application. It covers the advent of branched polystyrenes, syndiotactic polystyrene, high-molecular weight general purpose PS, styrenic interpolymers, and clear SBS copolymers Presents voluminous research previously only reported at conferences in one reference Unique coverage of a topic not found in the field

Poly Trimethylene Terephthalate

Poly Trimethylene Terephthalate
Author :
Publisher : Springer Nature
Total Pages : 308
Release :
ISBN-10 : 9789811973031
ISBN-13 : 9811973032
Rating : 4/5 (31 Downloads)

Book Synopsis Poly Trimethylene Terephthalate by : A. R. Ajitha

Download or read book Poly Trimethylene Terephthalate written by A. R. Ajitha and published by Springer Nature. This book was released on 2023-05-08 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains general concepts of an important engineering thermoplastic polymer—polytrimethylene terephthalate (PTT). It describes preparation methods, characterization techniques, and various applications of PTT-based blends, IPNs, and composites. It also gives a clear idea about the engineering thermoplastic, PTT, and its importance in future. In addition to the basic concepts of PTT-based materials, the book also includes novel studies and issues on this topic. This book is an outcome of contributions by experts from different disciplines with various backgrounds and expertise. This book is useful for professionals, researchers, industrial practitioners, graduate students, and senior undergraduates of polymer science and engineering. Additionally, it is also beneficial for researchers working on materials science, surface science, bioengineering, chemical engineering, and nanomaterials. This book helps the researchers and students in expanding their knowledge in this field.

Encyclopedia of Polymer Blends, Volume 3

Encyclopedia of Polymer Blends, Volume 3
Author :
Publisher : John Wiley & Sons
Total Pages : 522
Release :
ISBN-10 : 9783527319312
ISBN-13 : 352731931X
Rating : 4/5 (12 Downloads)

Book Synopsis Encyclopedia of Polymer Blends, Volume 3 by : Avraam I. Isayev

Download or read book Encyclopedia of Polymer Blends, Volume 3 written by Avraam I. Isayev and published by John Wiley & Sons. This book was released on 2016-09-13 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and timely overview of the topic, this Encyclopedia imparts knowledge of fundamental principles and their applications for academicians, scientists and researchers, while informing engineers, industrialists and entrepreneurs of the current state of the technology and its utilization. The most comprehensive source on polymer blends available on the market Offers a complete and timely overview of the topic Each article presents up to date research & development on a topic and its basic principles and applications, integrates case studies, laboratory and pilot plant experiments, and gives due reference to published and patented literature Equips academics, scientists and researchers with knowledge of fundamentals principles and their applications, and informs the engineers, industrialists and entrepreneurs about the state of the art technology and its applications

Polymers - Opportunities and Risks I

Polymers - Opportunities and Risks I
Author :
Publisher : Springer
Total Pages : 454
Release :
ISBN-10 : 9783540884170
ISBN-13 : 3540884173
Rating : 4/5 (70 Downloads)

Book Synopsis Polymers - Opportunities and Risks I by : Peter Eyerer

Download or read book Polymers - Opportunities and Risks I written by Peter Eyerer and published by Springer. This book was released on 2010-08-06 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since their first industrial use polymers have gained a tremendous success. The two volumes of "Polymers - Opportunities and Risks" elaborate on both their potentials and on the impact on the environment arising from their production and applications. Volume 11 "Polymers - Opportunities and Risks I: General and Environmental Aspects" is dedicated to the basics of the engineering of polymers – always with a view to possible environmental implications. Topics include: materials, processing, designing, surfaces, the utilization phase, recycling, and depositing. Volume 12 "Polymers - Opportunities and Risks II: Sustainability, Product Design and Processing" highlights raw materials and renewable polymers, sustainability, additives for manufacture and processing, melt modification, biodegradation, adhesive technologies, and solar applications. All contributions were written by leading experts with substantial practical experience in their fields. They are an invaluable source of information not only for scientists, but also for environmental managers and decision makers.

Polyester-Based Biocomposites

Polyester-Based Biocomposites
Author :
Publisher : CRC Press
Total Pages : 339
Release :
ISBN-10 : 9781000891003
ISBN-13 : 1000891003
Rating : 4/5 (03 Downloads)

Book Synopsis Polyester-Based Biocomposites by : Senthilkumar Krishnasamy

Download or read book Polyester-Based Biocomposites written by Senthilkumar Krishnasamy and published by CRC Press. This book was released on 2023-09-29 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyester-Based Biocomposites highlights the performance of polyester-based biocomposites reinforced with various natural fibres extracted from leaf, stem, fruit bunch, grass and wood material. It also addresses the characteristics of polyester-based biocomposites reinforced with rice husk fillers and various nanoparticles. This book explores the widespread applications of fibre-reinforced polymer composites in the aerospace sector, automotive parts, construction and building materials, sports equipment and household appliances. Investigating the advantages of natural fibres, such as superior damping characteristics, low density, biodegradability, abundant availability at low cost and non-abrasive to tooling, this book discusses what makes them a cost-effective alternative reinforcement material for composites in certain applications. This book serves as a useful reference for researchers, graduate students and engineers in the field of polymer composites.

From linear to long-chain branched poly(ethylene terephthalate) – reactive extrusion, rheology and molecular characterization

From linear to long-chain branched poly(ethylene terephthalate) – reactive extrusion, rheology and molecular characterization
Author :
Publisher : Universitätsverlag der TU Berlin
Total Pages : 193
Release :
ISBN-10 : 9783798328914
ISBN-13 : 3798328919
Rating : 4/5 (14 Downloads)

Book Synopsis From linear to long-chain branched poly(ethylene terephthalate) – reactive extrusion, rheology and molecular characterization by : Kruse, Matthias

Download or read book From linear to long-chain branched poly(ethylene terephthalate) – reactive extrusion, rheology and molecular characterization written by Kruse, Matthias and published by Universitätsverlag der TU Berlin. This book was released on 2017-07-11 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Poly(ethylene terephthalate) is one of the most widely used polymers in packaging industry, due to its high mechanical strength, chemical resistance, and barrier functions. However, its processing is determined by degradation and low viscosity. In particular, foaming and film blowing is restricted by the linear structure of the molecule and low melt strength. The stability of three linear commercial PET grades produced by different synthesis routes with different molar masses is analyzed in regards of processing at industrial scale. Subsequently, reactive processing with three multi-functional chain extenders (pyromellitic dianhydride, PMDA, tetraglycidyl diamino diphenyl methane, TGDDM, and triphenyl phosphite, TPP) is conducted to create large and long-chain branched (LCB) molecules. The mechanical and molecular properties in melt state are analyzed by linear and non-linear viscoelastic rheology, modeling by the molecular stress function (MSF) theory and size-exclusion chromatography (SEC) with light scattering measurements. Thermal stability measurements in the linear viscoelastic regime revealed degradation and a reduction of the storage modulus in air atmosphere, and, besides thermal degradation, an enhancement of the modulus in nitrogen atmosphere, due to polycondensation [Kruse et al., 2013]. Fitting by an exponential function leads to the reconstruction of the initial state of the sample at zero-loading time and to a time constant, which reveals clear relations between stability and molar mass for all three PET grades in both atmospheres. High molar mass PET is more stable in nitrogen and less stable in air environment, and vice versa, depending on OH end group concentration and synthesis route. The analysis by means of time-resolved mechanical spectroscopy allows the observations of moduli and complex viscosity at a fixed time, a wide range of angular frequencies, and at different atmospheres, and revealed: (i) a plasticizer effect induced by small molecules from thermal and thermo-oxidative degradation, (ii) cross-linking leading to yield stress, (iii) diffusion influencing polycondensation reaction, (iv) slipping due to deposition of side products, and (v) an enhanced shear thinning regime [Kruse and Wagner, 2016]. The extrusion of neat PET with a twin-screw extruder at industrial scale leads to strong reduction of viscosity mainly due to shearing. The impact of thermo-oxidative degradation is comparably small. The reactive processing of the three PET grades with the three chain extenders leads to the conclusion that the tri-functional TPP is not a useful chain extender due to rapid degradation and toxicity. The two tetra-functional chain extenders, PMDA and the epoxy-based TGDDM, lead to strong viscosity increase, increasing strain hardening effect, and increasing thermal stability with increasing chain extender concentration as confirmed by loss- and storage modulus, phase angle, activation energy of flow, and elongational viscosity. The MSF model predictions show good agreement with data measured, and allowed a quantitative analysis of the branching structure and of the stretch of the molecules by both non-linear MSF parameters. In comparison to the high molar mass PET with an apparent comb-like structure at high PMDA concentrations, the two initially low molar mass grades show a higher molar mass after processing with PMDA and seem to have a tree-like structure, which can be explained by the hydroxyl end group concentration of these two PET grades. The extensive use of TGDDM leads to a hyperbranched and gel-like structure. The fracture analysis from uniaxial elongation experiments reveals a limiting stress value for high PMDA concentrations and a limiting strain value for high TGDDM concentrations due to formation of a covalent network. The molecular analysis by SEC with triple detection of the high molar mass PET, which was reacted with PMDA and TGDDM, shows a strong increase of the average molar masses, polydispersity, radius of gyration, and hydrodynamic radius and confirms the molar mass increase observed by the rheological measurements. The branching was confirmed by a decreasing Mark-Houwink exponent with increasing chain extender concentration. Further, the analysis of the contraction of the molecule revealed a more star-like structure at low concentrations for both chain extenders. With increasing concentration, the structure changed to more comb-like for PMDA and random tree-like or hyperbranched for TGDDM as was also observed by non-linear viscoelastic measurements. PMDA revealed to be an excellent coupling agent which induces reproducibly either a star-like, comb-like, or tree-like structures depending on the concentration of coupling agent added and the hydroxyl concentration of the PET employed. Polyethylenterephthalat (PET) zeichnet sich durch hervorragende mechanische Eigenschaften, sowie chemische Beständigkeit und Barriereeigenschaften aus und findet insbesondere in der Verpackungsindustrie Verwendung. Die Neigung zur Degradation und die wegen der linearen Kettenmoleküle geringe Viskosität schränken jedoch die Verarbeitbarkeit von PET wie beispielsweise das Schäumen und Folienblasen erheblich ein. In der vorliegenden Arbeit wird der Einfluss der thermischen Stabilität während der Verarbeitung von drei linearen industriellen PET-Typen untersucht, die sich durch Molmasse und Herstellungsverfahren unterscheiden. Des Weiteren wird langkettenverzweigtes PET (LCBPET) durch reaktive Verarbeitung mit drei verschiedenen multifunktionalen Kettenverlängerern, Pyromellitsäuredianhydrid (PMDA), Tetra- glycidyl-Diamino-Diphenyl-Methan (TGDDM) und Triphenylphosphit (TPP), hergestellt und charakterisiert. Durch die experimentelle Bestimmung der linearen und nichtlinearen rheologischen Eigenschaften der Schmelze und ihre Beschreibung mit Hilfe des sogenannten "Molecular Stress Function" (MSF) Modells gelingt eine quantitative Analyse des Materialverhaltens. Die molekulare Analyse wird zusätzlich durch die Ergebnisse von Gelpermeationschromatographie (GPC bzw. SEC) in Verbindung mit Lichtstreumessung gestützt. Die Untersuchungen der thermischen Stabilität von linearem PET im linear-viskoelastischen Bereich zeigen einen abnehmenden Speichermodul und somit ein thermo-oxidatives Degradationsverhalten in Luftatmosphäre. In inerter Stickstoffatmosphäre tritt hingegen nur thermische Degradation auf, gleichzeitig führt jedoch eine Polykondensationsreaktion zu einem Anstiegen des Moduls [Kruse et al., 2013]. Mit einem exponentiellen Regressionsansatz kann der anfängliche Zustand des Moduls in beiden Atmosphären zum Zeitpunkt Null, der dem Einbringen der Probe in das Rheometer entspricht, rekonstruiert werden. Die sich aus diesem Ansatz ergebende Zeitkonstante erlaubt es, quantitative Zusammenhänge zwischen der thermischen Stabilität der drei PET-Sorten und deren Molmasse sowie dem Herstellungsverfahren der PET-Typen aufzuzeigen. So weist hochmolekulares PET eine höhere Stabilität in Stickstoff und eine geringere Stabilität in Luft auf und umgekehrt. Hauptursache für dieses Verhalten ist die unterschiedliche Konzentration an Hydroxylendgruppen, die je nach Molmasse und Herstellungsmethode der jeweiligen PET-Typen variiert. Mit Hilfe der "Time-Resolved Mechnical Sprectroscopy" konnte die sich ändernde Viskosität über ein weites Frequenzspektrum und zu einer beliebigen Messzeit in beiden Atmosphären bestimmt werden. Wesentliche Ergebnisse dieser Untersuchung sind der Nachweis des Auftretens von (i) einem Weichmachereffekt bedingt durch die thermische und thermo-oxidative Degradation und den daraus resultierenden Oligomeren, (ii) dreidimensionaler Vernetzung mit der Ausbildung einer Fließgrenze, (iii) Diffusionsprozessen, die Einfluss auf die Polykondensationsreaktion haben, (iv) Wandgleiten, bedingt durch die Ablagerung von Nebenprodukten auf den Platten des Rheometers und (v) einem verbreiterten Scherverdünnungbereich [Kruse and Wagner, 2016]. Die Extrusion von linearem PET mit einem Doppelschneckenextruder unter industriellen Bedingungen führt zu einer starken Abnahme der Viskosität, die hauptsächlich durch Scherung und weniger durch thermo-oxidativen Abbau verursacht wird. Bei der reaktiven Verarbeitung der drei PET-Typen mit den drei verschiedenen Kettenverlängerern erwies sich das dreifunktionale TPP auf Grund von Toxizität und Lagerinstabilitäten als unbrauchbar. Die Verarbeitung der beiden vierfunktionalen Kettenverlängerer, PMDA und das epoxidhaltige TGDDM, führt zu erhöhter Viskosität, erhöhter Dehnverfestigung und erhöhter thermischer Stabilität mit zunehmender Konzentration des jeweiligen Kettenverlängerers. Das beschriebene Verhalten zeigt sich sowohl am Speicher- und Verlustmodul und dem daraus abgeleiteten Verlustwinkel, als auch an der Fließaktivierungsenergie und der Dehnviskosität. Dabei lassen sich die gemessenen Dehnviskositäten sehr präzise mit dem MSF-Modell beschreiben und die beiden nichtlinearen Modelparameter, β und f_max^2 ermöglichen eine quantitative Analyse der Verzweigungsstruktur und der Molekülstreckung. So zeigt die Modifiziereng von hohen PMDA-Konzentrationen und dem hochmolekularen PET eine mehr kammartige Struktur im Vergleich zu den beiden niedermolekularen PET-Typen, die eine baumartige Molekülstruktur und eine höhere Molmasse nach der reaktiven Extrusion aufweisen. Beide Effekte können mit der höheren OH-Endgruppenkonzentration der beiden niedermolekularen PET-Typen erklärt werden. Zu hohe Zusätze von TGDDM führen zu einem hochverzweigten und gelartigen Polymer. Das Bruchverhalten bei der uniaxialen Dehnung von mit einem hohen Zusatz von PMDA hergestellten langkettenverzweigten PET wird von einer limitierenden Bruchspannung bestimmt. Demgegenüber bestimmt eine maximale Dehnung das Bruchverhalten des mit einem hohen TGDDM-Zusatz hergestellten LCB-PET, verursacht durch ein kovalent gebundenes Polymernetzwerk. Die GPC Messungen mit drei Detektoren wurden an LCB-PET durchgeführt, das auf Basis der hochmolekularen PET-Type hergestellt wurde. Die molekulare Analyse der mit PMDA und TGDDM modifizierten Proben zeigt eine deutliche Zunahme der mittleren Molmassen, Molmassenverteilungsbreite, des Gyrationsradius und des hydrodynamischen Radius und bestätigt somit die rheologischen Ergebnisse. Das Auftreten von Verzweigungen wird außerdem durch den abnehmenden Mark-Houwink-Exponenten bei zunehmender Additivkonzentration verdeutlicht. Eine genauere Betrachtung weist auf eine sternartige Molekülstruktur bei geringer Zugabe beider Kettenverlängerer hin. Bei erhöhter Zugabe hingegen tritt eine kammartige Struktur bei PMDA und eine baumartige oder hochverzweigte Struktur bei TGDDM auf, wie auch aus den nichtlinearen viskoelastischen Messungen zu schließen ist. Insbesondere PMDA erweist sich als hervorragender Kettenverlängerer, der bei reaktiver Extrusion reproduzierbar eine sternartige, kammartige oder baumartige Molekülstruktur in Abhängigkeit von der verwendeten PET-Type und der PMDA-Konzentration ermöglicht und so das Verarbeitungsspektrum von PET auf neue Anwendungsgebiete erweitert.