Download or read book Hydrogen bonded Polymeric Complexes Containing Main Chain Liquid Crystalline Order and the Effect of Crosslink Rigidity on the Formation of Polymer Networks Via Hydrogen bonding Interactions written by Kari Nadine Haley and published by . This book was released on 1999 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrogen Bonded Polymers written by Wolfgang Binder and published by Springer. This book was released on 2007-02-20 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Control of polymeric structure is among the most important endeavours of modern macromolecular science. In particular, tailoring the positioning and strength of intermolecular forces within macromolecules by synthetic me- odsandthusgaining structuralcontrolover the?nalpolymeric materials has become feasible, resulting in the?eld of supramolecular polymer science. - sides other intermolecular forces, hydrogen bonds are unique intermolecular forces enabling the tuning of material properties via self-assembly processes -1 overawiderangeofinteractionstrengthrangingfromseveralkJmol tosev- -1 eraltensofkJmol . Centralfortheformationofthesestructuresareprecursor molecules of small molecular weight (usually lower than 10 000), which can assembleinsolidorsolutiontoaggregatesofde?nedgeometry. Intermolecular hydrogenbondsatde?nedpositionsofthesebuildingblocksaswellastheir- spectivestartinggeometryandtheinitialsizedeterminethemodeofassembly into supramolecular polymers forming network-, rodlike-,?brous-, disclike-, helical-, lamellar- and chainlike architectures. In all cases, weak to strong hydrogen-bondinginteractionscanactasthecentralstructure-directingforce fortheorganizationofpolymerchainsandthusthe?nalmaterials'properties. Theimportantcontributionofhydrogenbondstotheareaofsupramole- lar polymer chemistry is de?nitely outstanding, most of all since the potency of hydrogen-bonding systems has been found to be unique in relation to other supramolecular interactions. Thus the high level of structural diversity of many hydrogen-bonding systems as well as their high level of direction- ity and speci?city in recognition-phenomena is unbeaten in supramolecular chemistry. The realization, that their stability can be tuned over a wide range of binding strength is important for tuning the resulting material prop- ties, ranging from elastomeric to thermoplastic and even highly crosslinked duroplastic structures and networks. On the basis of the thermal reversib- ity, new materials with highly tunable properties can now be prepared, - ing able to change their mechanical and optoelectronic properties with very smallchangesofexternalstimuli. Thusthe?eldofhydrogen-bondedpolymers forms the basis for stimuli responsive and adaptable materials of the future.

Download or read book Hydrogen bonded Interpolymer Complexes written by Vitaliy V. Khutoryanskiy and published by World Scientific. This book was released on 2009 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been an increased interest among researchers in hydrogen-bonded interpolymer complexes since the first pioneering papers were published in the early 1960s. Several hundred research papers have been published on various aspects of complex formation reactions in solutions and interfaces, properties of interpolymer complexes and their potential applications. This book focuses on the latest developments in the area of interpolymer complexation via hydrogen bonding. It represents a collection of original and review articles written by recognized experts from Germany, Greece, Kazakhstan, Poland, Romania, Russia, UK, Ukraine, and the USA. It highlights many important applications of interpolymer complexes, including the stabilization of colloidal systems, pharmaceuticals, and nanomaterials.

Download or read book Hydrogen Bonding in Polymeric Materials written by Shiao-Wei Kuo and published by John Wiley & Sons. This book was released on 2018-01-18 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizing our current knowledge of the topic, this book describes the roles and effects of hydrogen bonding in polymer materials by reviewing the latest developments over recent years. To this end, it discusses all relevant aspects from the fundamentals, via characterization, to properties and applications in various polymeric materials, including polymer blends, block copolymers, mesoporous materials, biomacromolecules and nanocomposites. Invaluable reading for scientists in polymers and materials as well as those working in macromolecular chemistry.

Download or read book Polymer Networks Containing Reversibly Associating Side groups written by Jiahui Li and published by . This book was released on 2011 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Supramolecular polymers consist of low molar mass subunits that non-covalently bind together through hydrogen bonding or other non-covalent interactions, forming macromolecular assemblies. Site-specific and reversible hydrogen bonds and other non-covalent interactions are increasingly employed to modify bulk polymer properties, enabling thermoplastic elastomers and self-healing polymers. In this thesis, I investigate how hydrogen bonding groups directly bonded onto an elastic polymer network affect material properties. A lightly crosslinked covalent network containing hydrogen bonding side-groups (ureidopyrimidinone, UPy) was synthesized. This architecture results in a novel shape-memory effect, and the molecular events resulting in this behavior were deduced. Further, to systematically evaluate how thermomechanical properties are related to network architecture, a new photo-crosslinking route was developed to prepare shape-memory elastomers. This method enables melt-processing of shape-memory elastomers into complex permanent shapes, and samples can be prepared with much higher UPy-content. Furthermore, the covalent and non-covalent crosslink density can be accurately controlled. Dynamic mechanical analysis on photo-crosslinked shape-memory elastomers revealed that dynamic crosslinks behave nearly as effectively as permanent crosslinks below the UPy hydrogen bond transition. Compared to linear polymers bearing identical hydrogen bonding groups, the synthesized dynamic networks exhibit an enhanced temperature dependence of mechanical properties. This indicates that the covalent network supports cooperative hydrogen bonding. This finding will guide researchers to more effectively employ non-covalent interactions within bulk polymer materials. Mass transport through dynamic networks was also studied using multi-photon fluorescence recovery after photobleaching (MP-FRAP). In contrast to viscous relaxation, small molecule mass transport through the dynamic networks is limited by the density of hydrogen bonds instead of their exchange rate"--Leaves vii-viii.

Download or read book Crosslinking and Scission in Polymers written by O. Güven and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: MOLECULAR WEIGHr CHANGES AND NE1WORK FORMATION BY SCISSION AND CROSSUNKING A. Charlesby 1 Introduction Main Chain Scission of Polymers ____________________________ _ ________________________ _ 1 Crosslinking ______ . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . _ . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . __ . . . . _ . . . . . . . . . . . _ . . . . . . . . ___ . . _. __ . . . . _. _. _____ . _____ . _ 4 5 Random Crosslinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enhanced Crosslinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Other Forms of Crosslinking . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . _. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Combined Crosslinking and Scission ___________ _________________ ______ _ ______________ . _. _. 11 Antioxidants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fillers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . __ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . __ . . . 12 Crosslinking of Polymers in Solution ________________________________ . . ______________ . . . . __ 12 References _. __ _ 13 HIGH ENERGY RADIATION-AND UV UGHr-INDUCED CROSSLINKING AND CHAIN SCISSION w. Schnabel Introduction 15 Importance of Radiation-Induced Crosslinking and Main-Chain Scission in Linear Polymers ___________________________ _________________ 15 TYPes of Radiation and Radiation Sources _. ___________________________ . . . . . . . . . _ . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . _. _. _ . . __ . . . 16 Absorption of Radiation . . _ . . . . _ . . . . . . _ . . _ . . __ . _ . . . . . . . . ____ . . . _ . . . . . . . . . . . . __ . . . . _ . . . . . . . . . _ . . . . _ . . . . . . _ . . . _ . . _ . . . . . . . . . . . . . . . . . . . . . _ . . . . . __ . . . . . . . . . . . _ . . . . . _____ . . . . . . . . . ___ . . . 16 General Aspects Concerning XL and CS in Linear Polymers ______________________ . _________ . _____ . _____ 22 Random and Specific Site Attacks . . . . . . . _. ____ . _ . . . _ . . . . . . . . . . __ . . . . . . . . . . . . . _ . . ___ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . _ . . . . . __ . . . . _ . . . . . . _ . . . . __ . ___ . . . . . . . . . . __ . . _ 22 Detection of XL and CS . . . _. _ . . . . . . . . . . . . . . . _. __ . . . _ . . . . . . . . . . . . ___ . . . . . . . __ . . . _ . . . _ . . . . . . . . ____ . . . . . . . . . . . . . . . . . . _ . . . . _ . . . . . _ . . . . . . . . . . . . . . . . . . . . __ . . . . . _ . . . . _ . . . . . _. _ . . . . _ . . . . . . . 22 Simultaneous XL and CS Mechanisms 25 Ion Beam-Induced Radiation Effects In Linear Polymers ____________________________________________________ .

Download or read book Hydrogen Bonded Supramolecular Structures written by Zhan-Ting Li and published by Springer. This book was released on 2015-01-12 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the advances in the studies of hydrogen-bonding-driven supramolecular systems made over the past decade. It is divided into four parts, with the first introducing the basics of hydrogen bonding and important hydrogen bonding patterns in solution as well as in the solid state. The second part covers molecular recognition and supramolecular structures driven by hydrogen bonding. The third part introduces the formation of hollow and giant macrocycles directed by hydrogen bonding, while the last part summarizes hydrogen bonded supramolecular polymers. This book is designed to bring together in a single volume the many important aspects of hydrogen bonding supramolecular chemistry and will be a valuable resource for graduates and researchers working in supramolecular and related sciences. Zhan-Ting Li, PhD, is a Professor of Organic Chemistry at the Department of Chemistry, Fudan University, China. Li-Zhu Wu, PhD, is a Professor of Organic Chemistry at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, China.

Download or read book Conjugated Polymers and Small Molecules with Latent Hydrogen bonding for Organic Electronic Applications written by Kun Yang and published by . This book was released on 2017 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated polymers and small molecules are gaining a growing attention as the active materials for flexible and printed electronics. The present work discusses the exploration of novel conjugated polymers and small molecules with latent hydrogen-bonding on the conjugated backbone for electronic applications. In the first study, we synthesized a class of conjugated polymers with latent hydrogen-bonding utilizing Suzuki coupling reactions. The resulting polymers can be converted into actual hydrogen-bonded polymers upon thermal or UV removal of the t-butoxyl carbonyl (t-Boc) protection groups on the main chains. Large bathochromic absorption shift and dramatically decreased material solubility of the polymer were shown after the formation of hydrogen-bonding, indicating their enhanced interchain interactions. Photolithographic patterned electrochromic devices was fabricated and tested with the latent hydrogen-bonded conjugated polymers. The second study extends in assessing the field-effect transistor performance of two diketopyrrolopyrrole-based conjugated small molecules with latent hydrogen-bonding. Effects of the activation of latent hydrogen-bonding networks on the small molecule film properties, including UV/Vis absorption, band gap, solvent resistance, film morphology, molecular packing mode, and charge mobility are investigated. Highly crystalline films and improved field-effect mobility of the device was observed for both small molecules after the hydrogen-bonding activation, suggesting an efficient control of molecular organization and device performance of the latent hydrogen-bonding strategy. Based on similar principles, a series of conjugated statistical copolymers with varied latent hydrogen-bonding content on the main chain were studied in the third part of this work. Increased hole mobility was observed for the organic field-effect transistor devices of polymers in which higher percentage of hydrogen-bonded repeating units were comprised, which suggested the potential of latent hydrogen-bonding strategy in constructing solution-processed conjugated polymers with improved semiconducting performance.

Download or read book Self Healing Polymers written by Wolfgang H. Binder and published by John Wiley & Sons. This book was released on 2013-03-29 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-healing is a well-known phenomenon in nature: a broken bone merges after some time and if skin is damaged, the wound will stop bleeding and heals again. This concept can be mimicked in order to create polymeric materials with the ability to regenerate after they have suffered degradation or wear. Already realized applications are used in aerospace engineering, and current research in this fascinating field shows how different self-healing mechanisms proven successful by nature can be adapted to produce even more versatile materials. The book combines the knowledge of an international panel of experts in the field and provides the reader with chemical and physical concepts for self-healing polymers, including aspects of biomimetic processes of healing in nature. It shows how to design self-healing polymers and explains the dynamics in these systems. Different self-healing concepts such as encapsulated systems and supramolecular systems are detailed. Chapters on analysis and friction detection in self-healing polymers and on applications round off the book.

Download or read book Supramolecular Assembly Via Hydrogen Bonds II written by David M.P. Mingos and published by Springer Science & Business Media. This book was released on 2004-02-20 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics of Hydrogen Bonding Polymer Blends Exhibiting Minimized Self Associations and Liquid Crystalline Polymers of Unique Chemistry written by Kevin Allen Masser and published by . This book was released on 2010 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulk Supramolecular Polymerization Via weak Hydrogen Bonds and Aromatic Interactions written by Nicholas Francis Shaun Lanigan and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Bulk supramolecular polymers offer an attractive strategy for the development of functional materials. The use of small molecule monomers is of particular interest, because they maximize the potential of a fully reversible polymer backbone. However, the use of small molecules to generate bulk supramolecular polymers has been hindered by the difficulties associated with monomer design. In particular, the tendency of small molecules to crystallize and the lack of understanding of how intermolecular interactions direct the packing of molecules in bulk, make the rational design of novel monomers challenging. To explore the potential of metal coordination geometry, the organometallic molecule CpFe(CO)PPh3CO(CH2)5CH3 (FpC6) was selected as a candidate for use as a monomer to prepare a bulk supramolecular polymer. To elucidate the packing motif and potential intermolecular interactions, crystal engineering of FpC6 was performed. FpC6 forms 5 different crystal structures depending on recrystallization conditions. Crystal engineering revealed that FpC6 interacts through a variety of C-H--O interactions and aromatic embraces, which are influenced by the recrystallization conditions. Depending on recrystallization conditions, FpC6 forms three unique one-dimensional chain structures in the crystalline material. When the crystalline solid-state structure was disrupted by melting, FpC6 displayed typical polymer behaviour, such as the ability to form free-standing films, and fibres could be drawn from the melt. Upon cooling, FpC6 did not immediately recrystallize and instead formed an amorphous solid which could be molded into a variety of shapes. Powder X-ray diffraction of the amorphous solid revealed a distinctive double peak pattern. The double peak pattern matched the inter-monomer distances for a ladder chain structure (identified via crystal engineering) formed by cooperative C-H--O hydrogen bond and aromatic embraces. Differential scanning calorimetry indicated that no recrystallization occurred and that FpC6 underwent a glass transition. These results demonstrated that the C-H--O hydrogen bonds and aromatic embraces are strong enough to stabilize the chain and prevent crystallization. However, FpC6 eventually crystallized over time, indicating that the chains were metastable. The mechanical behaviour of FpC6 was found to be very rich and complex, as it was sensitive to temperature, ageing and thermal/measurement history. Rheological experiments indicated that aged FpC6 demonstrates viscoelastic behaviour, potentially due to the presence of chain entanglements. In order to improve the reproducibility of the mechanical behaviour, the influence of thermal history on FpC6 was investigated to establish a reproducible initial state. Differential scanning calorimetry experiments revealed that the glass transition temperature of FpC6 decreased with increasing upper heating temperature and annealing time, suggesting that the network was not at equilibrium and changed over time. Based on temperature-dependent PXRD experiments of aged FpC6, the decrease in Tg was attributed to the de-polymerization of the supramolecular chains. Annealing FpC6 at temperatures above the Tm indicated that the chains disassembled faster at higher temperatures. Hysteresis experiments showed that no significant polymerization occurred during subsequent cooling or reheating cycles. FpCx (x = 5, 8 and 10) analogues with different alkyl chain lengths were prepared to investigate the effect of alkyl chain length. Preliminary investigation revealed that the FpCx analogues also formed bulk supramolecular polymers with the same chain structure as FpC6. Additionally, as the alkyl chain length increased, the glass transition temperature decreased FpC6 and its analogues are the first reported bulk supramolecular polymers formed via aromatic embraces and weak hydrogen bonding and represent an opportunity for novel monomer design.

Download or read book Synthesis Characterization and Rheology of Functional and Heterocyclic Liquid Crystalline Polymers written by Wenyi Huang and published by . This book was released on 2006 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three segmented main-chain thermotropic liquid crystalline polymers (TLCPs) functionalized with nitrogen-containing heterocyclic groups were synthesized; namely PyHQ12 having pendent pyridyl group, PABP having side-chain azopyridyl group with flexible spacer, and PTBP containing side-chain terpyridine group with flexible spacer. The principles of specific interactions were applied to prepare supramolecular structures and organoclay or clay nanocomposites based on these functional TLCPs. Three combined main-chain/side-chain liquid-crystalline polymers (MCSCLCPs) were prepared via hydrogen bonding or ionic interactions based on PyHQ12 and PABP. The presence of hydrogen bonds in self-assembled PyHQ12-7CNCOOH and PABP-AA, and the presence of ionic interactions in self-assembled PABP-TSA, which exist above their respective clearing temperatures, were confirmed using Fourier transform infrared (FTIR) spectroscopy, the thermal transitions in each MCSCLCP were determined using differential scanning calorimetry (DSC), and the mesophase structures of each self-assembled MCSCLCP were characterized using polarized optical microscopy (POM) and wide-angle X-ray diffraction (WAXD). PyHQ12 was observed to be very effective in exfoliating organoclay (Cloisite 30B) aggregates, because of the formation of hydrogen bonds, as determined by in situ FTIR spectroscopy, between the pendent pyridyl group in PyHQ12 and the hydroxyl groups in the surfactant MT2EtOH residing at the surface of Cloisite 30B. Thus, functionality in TLCP is necessary to obtain highly dispersed organoclay nanocomposites, but at the same time there is a possibility to lose some degree of liquid crystallinity in the TLCP, due to the proximity of the pendent pyridyl group to the mesogenic main-chain backbone. Thus, another functional TLCP, PABP having side-chain azopyridyl group with flexible spacer, was synthesized. It has been found that the liquid crystallinity of PABP in the organoclay nanocomposites was more or less intact and yet organoclay (Cloisite 30B) aggregates were very well dispersed, which was attributed to the fact that the pyridyl group in the side-chain azopyridine of PABP is located sufficiently far away from the mesogenic main chain. The rheological properties of functional TLCP/organoclay nanocomposites were also investigated. A unique polymer/ruthenium complex [RuII(PTBP)(6TPy)](PF6)2 based on PTBP was used to prepare natural clay (Montmorillonite, MMT) nanocomposite. X-ray diffraction and transmission electron microscopy indicate that MMT has a high degree of exfoliation in the matrix of PTBP/ruthenium complex. UV-vis spectroscopy and FTIR spectroscopy show that the driving force for exfoliating MMT in PTBP/ruthenium complex is attributable to the Coulombic interactions between the positively charged ruthenium center in the side chain of the polymer and the negatively charged clay surfaces.

Download or read book Hydrogen bonded Main chain Liquid Crystalline Association Polymers written by Chien-Ming Lee and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Crystalline Polymers written by Division on Engineering and Physical Sciences and published by National Academies Press. This book was released on 1990-02-01 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Hydrogen bonded Main chain Liquid Crystalline Polymers written by Shampa Roychowdhury and published by . This book was released on 1996 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Synthesis written by and published by Springer Science & Business Media. This book was released on 2004-10-08 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. T. Takata, N. Kihara, Y. Furusho: Polyrotaxanes and Polycatenanes: Recent Advances in Syntheses and Applications of Polymers Comprising of Interlocked Structures.- 2. M. Suginome, Y. Ito: Transition Metal-Mediated Polymerization of Isocyanides.- 3. K. Osakada, D. Takeuchi: Coordination Polymerization of Dienes, Allenes and Methylenecycloalkanes.