Download or read book Synthesis and Characterization of Thermotropic Liquid Crystalline Poly ester imide s written by Jinseo Ahn and published by . This book was released on 1996 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A series of novel poly(ester-imide)s were prepared by the reactions of 6,6'-(3,3',4,4'-benzophenonetetracarboxylic diimido)-bis-hexanoic acid with various aliphatic diols containing four to ten methylene groups using a melt polymerization technique. Besides these, a novel poly(esterimide) was synthesized by the reaction of 1 1, 1 1 '-(3,3', 4,4'- benzophenonetetracarboxylic diimido)-bis-undecanoic acid with 1,6-hexanediol employing the same technique. Two kinds of monomers containing diimide diacids were prepared by the reactions of 3,3',4,4'-benzophenonetetracarboxylic dianhydride with respective 6-aminocaproic acid and 1 1 -aminoundecanoic acid. A total of eight poly(ester-imide)s, PEIMs, were characterized for liquid crystalline properties. The solubility, viscosity, infrared spectroscopy, thermal analyses such TGA and DSC, and the optical studies were performed. Infrared spectra of PEIMs confirmed the formation of imide and ester groups. These poly(ester-imide)s exhibited high thermal and oxidative stability and very poor solubility corresponding to high viscosity. There were no reproducible endothermic or exothermic peaks found besides glass transition temperatures in the DSC thermograms. In addition, no PEIMs showed birefringent textures under the polarized light microscope. DSC and optical study indicated that Odd PEIMs and PEIM(6,10) are totally amorphous, while Even PEIMs are partially crystalline polymers with extremely slow crystallization rate. Two new compounds, BTDI-1 1 A/1 8-ol and BPDI-1 1 A/1 8-ol, with small molecular weight were designed and synthesized. The reaction of respective BTDI-1 1 A and BPDI-1 1 A with 1 -octadecanol was performed in boiling toluene with azeotropic removal of water by using Dean-Stark apparatus. DSC and optical study with polarized light microscopy indicated that BTDI-1 1 A/1 8-ol has a liquid crystalline phase that is very close to solid crystal state, whereas BPDI-1 1 A/1 8-ol has no liquid crystalline property."--Abstract.
Download or read book Synthesis and Characterization of Low melting Thermotropic Liquid Crystalline Poly ester imide s written by Sunny Jacob and published by . This book was released on 1994 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Two new series of low-melting liquid crystalline poly(ester-imide)s, (PEIM(s)) containing biphenyldiimide mesogen with a high aspect ratio was prepared by the polycondensation of ll-(3,3',4,4'-biphenyltetracarboxydiimido)-bis undecanoic acid with various aliphatic diols and methyl esters of hydroquinone and 4,4'-biphenol by melt polymerization. The mesogenic diimide diacid was prepared by reacting 3,3',4,4'- biphenyltetracarboxylic dianhydride with 11 -amino undecanoic acid using the method of Augl and Wrasidlo. The synthesized polymers were characterized by Gel Permeation Chromatography (GPC), IR Spectroscopy, Dilute Solution Viscosity, Thermogravimetry (TGA), Differential Scanning Calorimetry (DSC) and Polarizing Light Microscopy (PLM). The data obtained from GPC indicated the presence of a wide distribution of molecular weights. The infrared spectra of the polymers showed multiple peaks due to the vibrational coupling of the imide carbonyl groups. The inherent viscosities ranged from 0.5 g/dL to 1.65 g/dL. Thermogravimetric analysis showed that these PEIM(s) have high thermal stability in both oxidizing and inert atmosphere. DSC and PLM studies indicated that these poly(ester-imide)s are semi-crystalline and the degree of crystallinity can be increased by annealing above glass transition. They showed all major thermal transitions. The DSC curves of these polymers showed crystal ordering exotherm(s), glass transition and melting endotherm(s). The glass transition temperature of the polymers decreased with increase in the number of methylene units. The melting point of the even polymers decreased from 136 C (n = 4) to 122 C (n = 12) and interestingly an opposite trend was noticed for 'odd' polymers. The melting point of the 'odd' PEIM(s) were lower than the 'even' ones. These polymers showed a definite odd-even effect in melting point. An additional melting endotherm was observed in the DSC heating curves obtained after annealing the samples at the crystal ordering temperature. This indicated that the title polymers exhibited an enantiotropic liquid crystalline behavior. The optical micrographs of the 'even' PEIM(s) observed between crossed polarizers after annealing indicated the presence of an ordered smectic phase below Tm2 and a less ordered smectic phase around Tm2. Formation of droplets near the clearing temperature followed by the formation of a coarse texture at a lower temperature in the case of 'odd' PEIM(s) are indicative of the presence of a nematic phase, below the isotropic transition temperature. Poly(esterimide) s containing aromatic diols showed higher transition temperatures than those containing aliphatic diols. Multiple endotherms were evident in the DSC thermograms of poly(ester-imide)s containing aromatic diols. The optical micrographs of the aromatic polymers taken at temperatures around Tm were comparable to the fine scale versions of the Schlieren texture. PLM studies and analysis of the cooling traces revealed that poly(ester-imide)s containing aliphatic diols have slow crystallization kinetics. The 'odd' PEIM(s) can be quench cooled from the isotropic melt to the isotropic glass. The rate of crystallization was found to be much faster in the case of polymers containing aromatic diols. The even and the aromatic poly(ester-imide)s were found to be more crystalline than the 'odd' ones. The poly(ester-imide) derived from aliphatic diol n = 7 showed unusual results in the DSC and PLM studies which is explained as a result of crosslinking or branching due to side reactions."--Abstract.
Download or read book Synthesis and Characterization of Novel Poly ester imide ether s Exhibiting Liquid Crystallinity written by Randy T. Pike and published by . This book was released on 1996 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A series of novel thermotropic poly(ester-imide-ether)s were synthesized by melt polymerization techniques. The imide dimethyl ester: N-[(carbomethoxy) phenyl]-4-(carbomethoxy) phthalimide, prepared in a series of reactions, was reacted with varying ratios of poly(tetramethylene ether) glycol and 1,6 hexane diol to give the copolymers in 56% to 96% yield. The polymers were characterized by differential scanning calorimetry, dilute solution viscosity, gel permeation chromatography, infrared spectroscopy, thermogravimetric analysis, and polarized optical microscopy. Inherent viscosity values range from 0.40 dl/g to 1.14 dl/g. Gel permeation chromatographic analysis of the initial polymer series showed number average molecular weights ranging from 32,000 g/mol to 100,000 g/mol. Glass transition temperatures range from -46 C to 44 C. The polymer series exhibit moderate thermal stability with thermal decomposition temperatures exceeding 360 C. Copolymers PEI-1-ET-9 (650) and PEI-3-ET-7 (650) showed no mesophase formation. Copolymers PEI-5-ET-5 (650), PEI-7-ET-3 (650), PEI-9-ET-1 (650), PEI-7-ET-3 (2000), PEI-9-ET-1 (2000), PEI-7-ET-3 (2900), and PEI-9-ET-1 (2900) displayed birefringent monotropic liquid-crystalline behavior."--Abstract.
Download or read book Preparation and Characterization of Semi Flexible Thermotropic Poly ester imide s written by John V. Facinelli and published by . This book was released on 1989 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A series of novel poly(ester-imide)s were prepared by the reaction of meta- and para-substituted trlmellltimide dicarboxylic diacid chlorides with various diols containing four, five, six, seven, eight, nine, ten and twelve methylene groups by a solution polymerization technique utilizing refluxing 1,2,4-trichlorobenzene as a solvent. The poly(ester-imide)s were characterized by dilute solution viscosity, infrared spectroscopy, differential scanning calorimetry and polarized light microscopy. The inherent viscosities of the meta-substituted poly(ester-imide)s ranged from 0.06 to 0.25 dL/g while those of the para-substituted poly(ester-imide)s ranged from 0. 1 0 to 0.65 dL/g and were obviously of higher molecular weight. The meta series were amorphous and showed no mesophase formation. The para-substituted poly(ester-imide)s having four, six, eight or ten methylene spacers showed birefringent liquid-crystalline behavior."--Abstract.
Download or read book Thermotropic Liquid Crystal Polymers written by Tai-Shung Chung and published by CRC Press. This book was released on 2001-03-01 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystal polymers are sometimes called super polymers--with good reason. Their wide range of exceptional properties and ease of processing make them design candidates for many demanding applications. This new book provides a thorough review of LCP technology with the emphasis on the chemistry, synthesis and characterization of the material in its many variants. Additional chapters cover processing and applications. From the Editor's Preface The field of thermotropic liquid crystalline polymers has grown substantially in the last two decades, with fundamental research, publications, commercial products, and patents. In the 1980's, Dr. Ralph Miano led my colleagues and me at Hoechst Celanese in commercializing the first thermotropic liquid crystalline polymers, based on Dr. Gordon Calundann's composition patents. Today, more than seven companies have produced thermotropic liquid crystalline polymer materials, with at least 50 variants available. Hence, it is timely to compile a comprehensive review on the nature of this type of material and the ongoing progress in this field.... The goals of this book are to summarize previous work, provide new insights into this class of polymers, and add to the understanding of the formation of liquid crystallinity. This book covers a wide range of topics and addresses different disciplines in the field. The chapters are arranged as a learning scheme for the professional, from basic science to applied engineering. The first few chapters summarize the syntheses of various polyester, polyester-amid, and polyimide liquid crystalline polymers. The science and origins of liquid crystal formation are revealed. Next, we introduce the characterizations of these materials by their different chemical and physical aspects. Because most commercially available thermotropic liquid crystalline polymers have been used in the form of composites, we have also incorporated a chapter on polymer blends, detailing blending mechanisms and resultant properties. Two chapters on thermosetting liquid crystalline polymers integrate them with other topics, because of their unique importance and their applications for microelectronics and packaging. The final chapter deals with the engineering and processing aspects of thermoplastic liquid crystalline polymers for a variety of applications.
Download or read book Handbook of Thermoplastics written by Olagoke Olabisi and published by CRC Press. This book was released on 2016-02-03 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new edition of the bestselling Handbook of Thermoplastics incorporates recent developments and advances in thermoplastics with regard to materials development, processing, properties, and applications. With contributions from 65 internationally recognized authorities in the field, the second edition features new and updated discussions of seve
Download or read book The Synthesis and Characterization of Thermotropic Liquid Crystal Compounds as Models for Reaction Injection Molded RIM type Polymers written by Guerry Leonard Grune and published by . This book was released on 1982 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ICCAP 2021 written by A Mohan and published by European Alliance for Innovation. This book was released on 2021-12-22 with total page 2763 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceeding constitutes the thoroughly refereed proceedings of the 1st International Conference on Combinatorial and Optimization, ICCAP 2021, December 7-8, 2021. This event was organized by the group of Professors in Chennai. The Conference aims to provide the opportunities for informal conversations, have proven to be of great interest to other scientists and analysts employing these mathematical sciences in their professional work in business, industry, and government. The Conference continues to promote better understanding of the roles of modern applied mathematics, combinatorics, and computer science to acquaint the investigator in each of these areas with the various techniques and algorithms which are available to assist in his or her research. We selected 257 papers were carefully reviewed and selected from 741 submissions. The presentations covered multiple research fields like Computer Science, Artificial Intelligence, internet technology, smart health care etc., brought the discussion on how to shape optimization methods around human and social needs.
Download or read book Progress in Polyimide Chemistry II written by H.R. Kricheldorf and published by Springer Science & Business Media. This book was released on 1998-11-26 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past four decades polymers containing imide groups (usually as build ing blocks of the polymer backbone) have attracted increasing interest of sci entists engaged in fundamental research as well as that of companies looking into their application and commercialization. This situation will apparently continue in the future and justifies that from time to time reviews be published which sum up the current state of knowledge in this field. Imide groups may impart a variety of useful properties to pol~'mers, e. g. , thermal stability chain stiffness, crystallinity, mesogenic properties, photoreactivity etc. These lead to a broad variety of potential applications. This broad and somewhat heteroge neous field is difficult to cover in one single review or monograph. A rather com prehensive monograph was edited four years ago by K. Mittal, mainly concen trating on procedures and properties of technical interest. Most reviews presented in this volume of Advances in Polymer Science focus on fundamen tal research and touch topics not intensively discussed in the monograph by K. Mittal. Therefore, the editor of this work hopes that the reader will appreci ate finding complementary information. Finally I wish to thank all the contributors who made this work possible and I would like to thank Dr. Gert Schwarz for the revision of the manuscripts of the contributions 3 and 4. Hamburg, September 1998 Hans R. Kricheldorf Contents Nanoporous Polyimides J. L. Hedrick, K. R. Carter, l. W. Labadie, R. D. Miller, W.
Download or read book Papers Presented at the Meeting written by American Chemical Society. Division of Polymer Chemistry and published by . This book was released on 1997 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Macromolecular Design of Polymeric Materials written by Hatada and published by CRC Press. This book was released on 1997-01-02 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a range of information on polymers and polymerization techniques, this text covers the gamut of polymer science from synthesis, structure and properties to function and applications. It analyzes speciality polymers, including acrylics, fluoropolymers, polysiplanes, polyphosphazenes, and inorganic and conducting polymers. The book examines the stereochemistry of polymerization and the stereoregularity of polymers.
Download or read book Multiphase Polymer Systems written by Andreea Irina Barzic and published by CRC Press. This book was released on 2016-09-19 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase morphology in multicomponent polymer-based systems represents the main physical characteristic that allows for control of the material design and implicitly the development of new plastics. Emphasizing properties of these promising new materials in both solution and solid phase, this book describes the preparation, processing, properties, and practical implications of advanced multiphase systems from macro to nanoscales. It covers a wide range of systems including copolymers, polymer blends, polymer composites, gels, interpenetrating polymers, and layered polymer/metal structures, describing aspects of polymer science, engineering, and technology. The book analyzes experimental and theoretical aspects regarding the thermal and electrical transport phenomena and magnetic properties of crucial importance in advanced technologies. It reviews the most recent advances concerning morphological, rheological, interfacial, physical, fire-resistant, thermophysical, and biomedical properties of multiphase polymer systems. Concomitantly the book deals with basic investigation techniques that are sensitive in elucidating the features of each phase. It also discusses the latest research trends that offer new solutions for advanced bio- and nanotechnologies. Introduces an overview of recent studies in the area of multiphase polymer systems, their micro- and nanostructural evolutions in advanced technologies, and provides future outlooks, new challenges and opportunities. Discusses multicomponent structures that offer enhanced physical, mechanical, thermal, electrical, magnetic, and optical properties adapted to current requirements of modern technologies. Covers a wide range of materials, such as composites, blends, alloys, gels and interpenetrating polymer networks. Presents new strategies for controlling the micro- and nanomorphology and the mechanical properties of multiphase polymeric materials. Describes different applications of multiphase polymeric materials in various fields, including automotive, aeronautics and space industry, displays, and medicine.
Download or read book Synthesis and Characterization of Side chain Liquid Crystalline Polymer and Polymer dispersed Liquid Crystals written by Xiangen Han and published by . This book was released on 2004 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid crystalline Polymers written by American Chemical Society. Meeting and published by . This book was released on 1990 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume explores the creation, study, and processing of new liquid-crystalline polymers. It covers not only the chemistry of liquid-crystalline polymers, but also the physics and engineering aspects of these materials. A wide range of topics is covered, including syntheses of main-chain and side-chain LCPs, structural characterization of LP, rheology and processing, and applications such a electro-optics and "self-reinforcing" blends. This book presents a broad view of the direction of LCP research in both industry and academe.
Download or read book Proceedings of the Rochester Academy of Science written by Rochester Academy of Science and published by . This book was released on 1998 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: List of members in v. 1-2, 4.
Download or read book Maro Polymer Notes written by and published by . This book was released on 2000 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Liquid Crystalline Esters Containing ODOPB Group and Its Inclusion Complexes written by 韋伊卡 and published by . This book was released on 2011 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
