Download or read book Synthesis and Characterization of Oligomers written by Constantin V. Uglea and published by CRC Press. This book was released on 1991-07-24 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an excellent introduction to the fundamentals of oligomer chemistry. Each section describes the synthesis, separation, physico-chemical characterization, and present and future applications of individual classes of oligomers organized according to the chemical structure of the main chain. In addition, this book features up-to-date references from both journals and patents and an extensive appendix covering synthesis and characterization methods of oligomeric derivatives. Synthesis and Characterization of Oligomers is a broad, state-of-the-art survey and will be useful not only for students and professionals working with oligomers, but also chemists who are new to the field.
Download or read book Synthesis and Characterization of Substituted Polyphenylene Oligomers written by Susan T. Pasco and published by . This book was released on 1997 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Modified Phenylethynyl Terminated Polyimides written by Alice C. Chang and published by . This book was released on 1998 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: As an ongoing effort to develop structural adhesives for high performance aerospace applications, recent work has focused on phenylethynl terminated imide (PETI) oligomers. The work reported herein involves the synthesis and characterization of a series of phenylethynyl containing oligomers designated as LaRC [trademark]MPEI (Modified Phenylethynyl Terminated Polymide). These oligomers contain mixtures of linear, branched and star-shaped molecules. The fully imidized polymers exhibited minimum melt viscosity as low as 600 poise at 335 degrees C. Ti/Ti lap shear specimens processed at 288 degrees C under 15 psi showed tensile shear strength of approx. 6000 psi and 5200 psi at ambient and 350 degrees F temperatures, respectively. The chemistry and properties of these new MPEIs are presented and compared to an optimized linear PETI, LaRC [trademark]-PETI-5.
Download or read book Polymer Polymer Miscibility written by Olagoke Olabis and published by Elsevier. This book was released on 2012-12-02 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer–Polymer Miscibility discusses miscibility of polymeric mixtures. This book explains the theoretical and practical aspects of polymer miscibility, which has become a considerable area of research in many academic and industrial laboratories. Comprised of seven chapters, this book starts with an overview of the physical nature of the variations of the basic polymer structure. This monograph then discusses the two cases of miscible polymer blends, namely, poly(vinyl chloride) (PVC)–butadiene/acrylonitrile copolymer (NBR) and polystyrene–poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) blends. This text explores the useful and unique properties of blends of poly(vinyl chloride) and butadiene/acrylonitrile copolymer rubber. Other chapters discuss the thermodynamic theories for the phase separation of block copolymers. The reader is also introduced to other variations of chemical structure, which can result in the permanent attachment of polymers to each other through block and graft copolymers. This text also explores the feasibility of covalent bonding of polymer components. This book is intended for chemical engineers and materials scientists.
Download or read book Monomers Polymers and Composites from Renewable Resources written by Mohamed Naceur Belgacem and published by Elsevier. This book was released on 2011-10-10 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progressive dwindling of fossil resources, coupled with the drastic increase in oil prices, have sparked a feverish activity in search of alternatives based on renewable resources for the production of energy. Given the predominance of petroleum- and carbon-based chemistry for the manufacture of organic chemical commodities, a similar preoccupation has recently generated numerous initiatives aimed at replacing these fossil sources with renewable counterparts. In particular, major efforts are being conducted in the field of polymer science and technology to prepare macromolecular materials based on renewable resources. The concept of the bio-refinery, viz. the rational exploitation of the vegetable biomass in terms of the separation of its components and their utilisation as such, or after suitable chemical modifications, is thus gaining momentum and considerable financial backing from both the public and private sectors. This collection of chapters, each one written by internationally recognised experts in the corresponding field, covers in a comprehensive fashion all the major aspects related to the synthesis, characterization and properties of macromolecular materials prepared using renewable resources as such, or after appropriate modifications. Thus, monomers such as terpenes and furans, oligomers like rosin and tannins, and polymers ranging from cellulose to proteins and including macromolecules synthesized by microbes, are discussed with the purpose of showing the extraordinary variety of materials that can be prepared from their intelligent exploitation. Particular emphasis has been placed on recent advances and imminent perspectives, given the incessantly growing interest that this area is experiencing in both the scientific and technological realms. Discusses bio-refining with explicit application to materials Replete with examples of applications of the concept of sustainable development Presents an impressive variety of novel macromolecular materials
Download or read book Tau oligomers written by Jesus Avila and published by Frontiers E-books. This book was released on 2014-08-18 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neurofibrillary tangles (NFTs) composed of intracellular aggregates of tau protein are a key neuropathological feature of Alzheimer’s Disease (AD) and other neurodegenerative diseases, collectively termed tauopathies. The abundance of NFTs has been reported to correlate positively with the severity of cognitive impairment in AD. However, accumulating evidences derived from studies of experimental models have identified that NFTs themselves may not be neurotoxic. Now, many of tau researchers are seeking a “toxic” form of tau protein. Moreover, it was suggested that a “toxic” tau was capable to seed aggregation of native tau protein and to propagate in a prion-like manner. However, the exact neurotoxic tau species remain unclear. Because mature tangles seem to be non-toxic component, “tau oligomers” as the candidate of “toxic” tau have been investigated for more than one decade. In this topic, we will discuss our consensus of “tau oligomers” because the term of “tau oligomers” [e.g. dimer (disulfide bond-dependent or independent), multimer (more than dimer), granular (definition by EM or AFM) and maybe small filamentous aggregates] has been used by each researchers definition. From a biochemical point of view, tau protein has several unique characteristics such as natively unfolded conformation, thermo-stability, acid-stability, and capability of post-translational modifications. Although tau protein research has been continued for a long time, we are still missing the mechanisms of NFT formation. It is unclear how the conversion is occurred from natively unfolded protein to abnormally mis-folded protein. It remains unknown how tau protein can be formed filaments [e.g. paired helical filament (PHF), straight filament and twisted filament] in cells albeit in vitro studies confirmed tau self-assembly by several inducing factors. Researchers are still debating whether tau oligomerization is primary event rather than tau phosphorylation in the tau pathogenesis. Inhibition of either tau phosphorylation or aggregation has been investigated for the prevention of tauopathies, however, it will make an irrelevant result if we don’t know an exact target of neurotoxicity. It is a time to have a consensus of definition, terminology and methodology for the identification of “tau oligomers”.
Download or read book Polyimides written by K.L. Mittal and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt: This and its companion Volume 2 chronicle the proceedings of the First Technical Conference on Polyimides: Synthesis, Char acterization and Applications held under the auspices of the Mid Hudson Section of the Society of Plastics Engineers at Ellenville, New York, November 10-12, 1982. In the last decade or so there has been an accelerated interest in the use of polyimides for a variety of applications in a number of widely differing technologies. The applications of polyimides range from aerospace to microelectronics to medical field, and this is attributed to the fact that polyimides offer certain desirable traits, inter alia, high temperature stability. Polyimides are used as organic insulators, as adhesives, as coat ings, in composites, just to name a few of their uses. Even a casual search of the literature will underscore the importance of this class of materials and the high tempo of R&D activity taking place in the area of polyimides. So it was deemed that a conference on polyimides was both timely and needed. This conference was designed to provide a forum for discussion of various ramifications of polyimides, to bring together scientists and technologists interested in all aspects of polyimides and thus to provide an opportunity for cross-pollination of ideas, and to highlight areas which needed further and intensi fied R&D efforts. If the comments from the attendees are a baro meter of the success of a conference, then this event was highly successful and fulfilled amply its stated objectives.
Download or read book Rheokinetics written by A. Ya. Malkin and published by John Wiley & Sons. This book was released on 2008-09-26 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Materials The Oligomer Approach written by Klaus Müllen and published by John Wiley & Sons. This book was released on 2008-11-20 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electroactive oligomers form an important class of advanced materials for the development of new devices such as thin-film, flexible batteries; semiconductors; large-area optical displays; and sensors. In addition, the study of oligomeric model compounds is an essential prerequisite for understanding and developing polymers for electronics and optoelectronics applications. Written and edited by leading scientists in the field, this applications-oriented handbook represents the first comprehensive, systematic study of electroactive oligomeric materials. Special emphasis is placed on a critical review of the literature; relevant materials and technical data are collected in tables throughout. Includes - materials synthesis - structure--property relationship as a function of chain-length - applications in optics and electronics - oligomers as models for polymers - the role of oligomers in tomorrow's technology? Electronic Materials - The Oligomer Approach offers a stimulating combination of basic concepts and practical applications. It is sure to become a standard reference source that no-one working in the field can do without.
Download or read book Heterophase Network Polymers written by Boris A Rozenberg and published by CRC Press. This book was released on 2020-02-03 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume explains the theory and experimental investigations in the preparation of heterophase polymer network materials through cure reaction-induced microphase separation (CRIMPS). It describes the synthesis of a new family of block- and graft-copolymers with controlled solubility in epoxies and characterizes CRIMPS processes using novel applications of known methods such as nuclear magnetic resonance, electron spin resonance and photochemistry. The text develops a new method for characterizing the molecular mass distribution (MMD) of linear and network polymers using thermomechanical analysis data, as well as new methods for determining internal stresses and flaw formation during thermoset curing. The CRIMPS theory will be helpful for researchers and engineers designing and improving toughened plastics and other smart heterophase network materials for different applications. The new method for MMD characterization of polymers in bulk will be very useful to quickly analyze a polymer's MMD and to design new polymers. This book will provide a useful reference for graduates, researchers and working professionals in polymer chemistry and physics and materials science.
Download or read book Synthesis and Characterizations of Poly organophosphazenes written by Roger De Jaeger and published by Nova Publishers. This book was released on 2004 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gleria (materials science, Padova University, Italy) and De Jaeger (chemistry, University of Sciences and Technologies, France) present the latest work in the synthesis and characterization of poly(organophosphazenes). The book opens with a general introduction on background, developments, and future perspectives, then covers the synthetic aspects of phosphazene polymers, with chapters on areas such as ambient temperature cationic condensation synthesis of polyphosphazenes and high molecular weight polyspirophosphazenes. Chapters on the characterization of phosphazene polymers in solution explore topics including thermal and mechanical properties of polyphosphazenes and electrochemical behavior of phosphazenes. Annotation : 2004 Book News, Inc., Portland, OR (booknews.com).
Download or read book The Synthesis Characterization and Structure property Relationships of Regioregular 4 4 dialkyl 2 2 bithiazole Oligomers and Polymers written by John I. Nanos and published by . This book was released on 2005 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sequence controlled Polymers written by Jean-François Lutz and published by ACS Symposium. This book was released on 2015-01-07 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume of the ACS Symposium series is dedicated to the emerging field of sequence-controlled polymers. The objectives of this new research discipline include the synthesis, characterization, and exploitation of synthetic macromolecules containing ordered sequences of comonomers. This topic has gained significant importance in academic polymer research during the last several years. The community, which was initially composed of a few isolated researchers, has rapidly grown in a dynamic international network. As a consequence, the first international symposium on sequence-controlled polymers was organized at the 246th American Chemical Society national meeting in Indianapolis. All the chapters in this volume are related to the invited oral presentations that were given during the symposium. This selection of papers gives an overview of the field and highlights its interdisciplinary nature. Indeed, the symposium participants and the authors of this book are not only polymer chemists, but also organic chemists, supramolecular chemists, and physico-chemists. As a matter of fact, the design of tailor-made sequence-controlled polymers is a topic that goes beyond the traditional barriers of synthetic polymer science. Sequence-Controlled Polymers: Synthesis, Self-Assembly, and Properties will be of interest to a broad readership, as it is the first book to explore the important topic of sequence-controlled polymers. Based on its recent academic impact, it is reasonable to expect that this field of research will continue to grow in the next decades.
Download or read book Peptides and Peptide based Biomaterials and their Biomedical Applications written by Anwar Sunna and published by Springer. This book was released on 2017-10-26 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid-binding peptides have been used increasingly as molecular building blocks in nanobiotechnology as they can direct the assembly and functionalisation of a diverse range of materials and have the ability to regulate the synthesis of nanoparticles and complex nanostructures. Nanostructured materials such as β-sheet fibril-forming peptides and α-helical coiled coil systems have displayed many useful properties including stimulus-responsiveness, modularity and multi-functionality, providing potential technological applications in tissue engineering, antimicrobials, drug delivery and nanoscale electronics. The current situation with respect to self-assembling peptides and bioactive matrices for regenerative medicine are reviewed, as well as peptide-target modeling and an examination of future prospects for peptides in these areas.
Download or read book Synthesis and Characterization of Polythiophene Derivatives written by Xin Chen and published by ProQuest. This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Chapter 1, the history of conducting polymers, especially polythiophene and its derivatives, was briefly reviewed. Different approaches of structural modifications to afford small bandgap polythiophene derivatives were discussed. The emergence of metal-containing polymers (metallopolymers) as functional materials has attracted tremendous attention around the world. Introduction of metals into thiophene-based oligomers and polymers, whether the backbone or the side chain of the pi-conjugated framework, the electronic, optical, or magnetic properties of the material are expected to be significantly affected by metals through various mechanisms. Synthesis methods to prepare poly(thienylene vinylene) were also briefly reviewed in this chapter. In Chapter 2, the motivations and objectives were briefly discussed. Two structurally similar compounds, thieno[3,4-d]-1,3-dithiole-2-thione and thieno[3,4-d]-1,3-dithiol-2-one are the starting point of this project due to their unique carbondithiolate structures, which may lead to metal-dithiolate coordinated oligomers or/and polymers, or polymers crosslinked by DTTTF units. For the preparation of monomers, six types of reactions were systematically studied with focus on thieno[3,4-d]-1,3-dithiol-2-one to prepare different direvatives. Different halogenated compounds, Mannich bases, chloromethylated compounds, a number of nucleophilic substituted derivatives and a DTTTF analogue from chloromethylated compounds were successful synthesized. All products were fully characterized through 1H and 13C-NMR, FT-IR, ESI-TOF high resolution mass spectroscopy. The halogenated products were prepared through halogensuccinimides or other halogenation reagents such as Br2, I2. These halogenated compounds may be candidates to prepare homopolymer and/or copolymers bearing carbondithiolate structures by cross-coupling reactions. 4,6-Bis(chloromethyl) thieno[3,4- d]-1,3-dithiol-2-one and its nucleophilic derivatives may be good monomers for the two-step precursor polymerization to achieve fully conjugated poly(thienylene vinylene) derivatives and even metallopolymers with metal-dithiolate coordinations. Attempted polymerization reactions to homopolymers and copolymers through directly C-C coupling, such as transitional metal catalyzed cross-coupling, Stille reaction, and Ullman reaction, et al. were discussed in the beginning of Chapter 3. Base-promoted and acid-promoted polymerizations were attempted to afford soluble precursor polymers with carbondithiolate structures. However, all the symmetrical thiophene derivatives did not successfully yield processable precursor polymers; asymmetrical monomers generated some possibilities for future study. Synthesis of thiophene-based oligomers, such as dimmers (dithienyl compounds), trimers (trithienyl compounds), and heptamers were also explored in chapter 3, followed by preparation of thiophene-based copolymers through Wittig-Horner reactions. Properties of oligomers, especially trimers were well characterized by NMR, FT-IR, and ESI-TOF. Several conjugated DTTTF derivatives from trimers were prepared by the triethyl phosphite cross-coupling method. These conjugated DTTTF compounds posses some unique properties. They are stable in solid forms, but may be doped in solution forms. The copolymers were characterized by elemental analysis, and FT-IR. UV-Vis spectra of copolymers show their bandgap values are aroud 1.87eV (UV edge calculation). In the Experimental chapter, all reaction conditions of preparation of new annulated thiophene derivatives and oligomers were documented in details. Physical and spectroscopic properties of these new compounds were also presented in this chapter. Key words. polythiophene, oligomer, conjugation, synthesis, characterization, DTTTF, metallopolymer.
Download or read book Protein Dimerization and Oligomerization in Biology written by Jacqueline M. Matthews and published by Springer Science & Business Media. This book was released on 2012-09-04 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume has a strong focus on homo-oligomerization, which is surprisingly common. However, protein function is so often linked to both homo- and hetero-oligomerization and many heterologous interactions likely evolved from homologous interaction, so this volume also covers many aspects of hetero-oligomerization.
Download or read book Polymer Yearbook written by Richard A. Pethrick and published by CRC Press. This book was released on 1987 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains reviews on state-of-the-art Japanese research presented in the annual Spring and Autumn meetings of the Japanese Polymer Science Society. The aim of this section is to make information on the progress of Japanese Polymer Science, and on topics of current interest to polymer scientists in Japan, more easily available worldwide.
