Download or read book Investigation of Helicity of Water Soluble Polycarbodiimides and Preparation of Nano Particles from Amphiphilic Polycarbodiimides written by Haibo Li and published by . This book was released on 2006 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: nano particles, helical polymer, water soluble polymer.
Download or read book Investigation of Helicity of Water Soluble Polycarbodiimides and Preparation of Nano Particles with Amphiphilic Polycarbodiimides written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a helical polymer, polycarbodiimides have been investigated for a period of time. But few water soluble polycarbodiimides had been synthesized and characterized. Since solubility of polycarbodiimides can be controlled by their side arms, achiral or chiral carbodiimides bearing hydrophilic tertiary amino group have been prepared. Single-handed sense hydrophilic polycarbodiimides were prepared from chiral monomers by achiral metal catalyst or from achiral monomers by chiral catalyst to give polycarbodiimides with predominately helical sense. The water solubility of these polycarbodiimides bearing tertiary amino groups is improved when they are methylated by methyl camphorsulfornic acid ester. Configurational and conformational predominately helical polycarbodiimides behave with different way when they are heated. For the former case, the polymers rearrange to their Thermodynamic Control Conformation (TCC) from Kinetic Control Conformation (KCC); for the later one, the polymer became racemic when annealed. The activation energies for the conformational change can be determined through Arrhenius plot analysis. Compared to the neutral polycarbodiimides bearing tertiary amino groups, the corresponding ionic polymers have higher activation energies. Helical induction of the water-soluble polycarbodiimides also has been investigated. CD spectrum was run for both the neutral and ionic polycarbodiimides and peptide mimics were found. In addition to the hydrophilic monomers, chiral or achiral hydrophobic carbodiimides were also synthesized and polymerized. Through living polymerizations, the amphiphilic polycarbodiimides were prepared from metal catalysts. Crew-cut nanoparticles have been prepared through a phase inversion method. Different conditions have been tried to achieve nano particles with different morphologies and sizes. In the nano particle preparation, water amount, acid amount and molecular weight play important roles in preparation of nano particles. TEM was u.
Download or read book Synthesis of Helical Polycarbodiimides and Their Properties written by Galappaththi De Silva and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycarbodiimides are a relatively new class of synthetic macromolecules. Their helical conformation and tunable pendant groups made them special class of polymer which displayed interesting properties. We evaluated the properties of carbodiimide polymers consisting of long chain branched aliphatic groups. Newly synthesized helical polycarbodiimides with branched aliphatic side chains were introduced to evaluate the effect of these branched alkyl chains on the properties of the polymers. These polymers displayed different thermal and lyotropic liquid crystalline properties depending on the amount of branched side chains attached to the polymer backbone. The synthesis of water-soluble polymers and their potential applications were extensively studied. The significant properties of the water-soluble polycarbodiimides were evaluated. The pH dependent behavior of self-assembled polycarbodiimides were studied. This could be a potential candidate for the nano carrier applications. In addition, we investigated biomimetic polycarbodiimides which exhibited antimicrobial and cytotoxic properties.
Download or read book Synthesis and Investigation of Chiral Polycarbodiimides with Reversible Dynamic Properties written by Justin Glenn Kennemur and published by . This book was released on 2010 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: polymer, helical, circular dichroism, polycarbodiimide, polyguanidine, polarimetry, conformational change.
Download or read book Synthesis of Polymer Nanoparticles Using Intramolecular Chain Collapse and Benzocyclobutene Chemistry written by Ajay Ramesh Amrutkar and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single chain polymer nanoparticle (SCPN) synthesis from different polymer precursors using benzocyclobutene (BCB) chemistry and intramolecular crosslinking was investigated in this study. Synthesis of highly fluorinated SCPNs from highly fluorinated uni-block copolymer precursor utilizing `pseudo-high dilution continuous addition technique' was investigated. GPC confirmed selective intramolecular crosslinking and TEM images supported formation of sub-20 nm spherical polymer nanoparticles. Amphiphilic SCPNs prepared via step-wise crosslinking of an amphiphilic di-block copolymer chain were investigated for their morphology using 4 different characterization techniques: TEM, AFM, DLS and DOSY-NMR. TEM and AFM images showed presence of discreet SCPNs as loosely crosslinked coils that flatten out when deposited on the surface forming pancake like morphology with ̃ 20 nm sizes. All the techniques showed presence of bimodal size distribution of these nanoparticles in solution. A smaller sized distribution represented discreet SCPNs whereas larger sized (>40 nm) distribution represented physical aggregates of SCPNs. These aggregates were broken down upon significantly diluting the solution of nanoparticles (=50 ng/mL). AFM analysis and water contact angle studies on thin films of amphiphilic SCPNs and polystyrene homopolymer blends proved that nanoparticles possess Janus-type morphology. In order to aid synthesis of SCPNs from block copolymer precursors, a new 2-component room temperature polymer crosslinking based on 1-acetoxyBCB containing polymers and a nucleophile was developed. Development of this system involved developing synthesis of new monomer (1-acetoxy-4 and 5-vinylBCB), synthesis of polymers containing this new monomer followed by optimization of their crosslinking reaction. Mechanism of crosslinking and structure of crosslinking unit formed for this crosslinking system was also identified. SCPNs were synthesized at room temperature from uni-block copolymer precursors using this new crosslinking system. Crosslinking reaction was characterized using 1H NMR, GPC and LS-GPC. Symmetric ABA tri-block copolymer precursors are proposed as precursors for synthesis of SCPNs of different morphologies employing intramolecular crosslinking. Initial results on synthesis of ABA tri-block copolymer containing highly immiscible blocks using chain extension approach is also reported.
Download or read book Chemistry and Technology of Carbodiimides written by Henri Ulrich and published by John Wiley & Sons. This book was released on 2008-03-11 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbodiimides play an important role as condensation agents in the synthesis of polypeptides, polynucleotides, polysaccharides and numerous other chemical transformations. Chemistry and Technology of Carbodiimides is the first book to examine both the chemistry and technology of carbodiimides. This book provides a comprehensive and in-depth coverage of the synthesis and reactions of this industrially important class of chemicals while focusing on industrial applications, including the $M-sectors of biochemical synthesis, pharmaceuticals, polymers, ceramics, and herbicides. Written by a well-known authority in the field this book will prove a valuable reference tool for anyone working in this area of chemistry.
Download or read book Self Organized Nanostructures of Amphiphilic Block Copolymers II written by Axel H.E. Müller and published by Springer Science & Business Media. This book was released on 2011-08-13 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block Copolymer Surfactant Mixtures in Aqueous Solution: Can we Achieve Size and Shape Control by Co-Micellization?, by Thomas Hellweg; Non-ionic Thermoresponsive Polymers in Water, by Vladimir Aseyev, Heikki Tenhu and Françoise Winnik; From Coordination Polymers to Hierarchical Self-Assembled Structures, by Yun Yan, Arie de Keizer, Martien A. Cohen Stuart and Nicolaas A. M. Besseling; Processes of Ordered Structure Formation in Polypeptide Thin Film Solutions, by Ioan Botiz, Helmut Schlaad and Günter Reiter; Amphiphilic Polymers at Interfaces, by Katarzyna Kita-Tokarczyk, Mathias Junginger, Serena Belegrinou and Andreas Taubert;
Download or read book Handbook of Fluoropolymer Science and Technology written by Dennis W. Smith and published by John Wiley & Sons. This book was released on 2014-05-05 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Fluoropolymer Science and Technology A comprehensive handbook on fluoropolymer synthesis, characterization, and processing Fluoropolymers, one of the more durable classes of polymer materials, are known to enable novel technologies as a result of their remarkable properties. As key components in industry applications, fluoropolymers have established commercial interest and scientists have discovered more efficient approaches of handling them. This book reviews up-to-date fluoropolymer platforms as well as recently discovered methods for the preparation of fluorinated materials. It focuses on synthesis, characterization, and processing aspects, providing guidelines for practicing scientists and engineers. In addition, the book covers: Concepts and studies from leading international laboratories, including academia, government, and industrial institutions Emerging technologies and applications in energy, optics, space exploration, fuel cells, microelectronics, gas separation membranes, biomedical instrumentation, and more Current environmental concerns associated with fluoropolymers, relevant regulations, and growth opportunities Overall, the chapters provide coverage of chemical methods and help the reader further understand how fluoropolymer research provides solutions for material challenges. The concepts in this book also inspire professionals to identify new markets and funding sources for fluoropolymer research and development.
Download or read book Optically Active Polymers written by E. Sélégny and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first four volumes of the series on 'Charged and Reactive Polymers' have been devoted to polymers in solution (Voh. I and II) or in gel and membrane forms (Vols. III and IV). In correlation with charges, other physical or chemical properties of macro molecules have been considered. Understanding of charge and hydrophobic effects is equally important for synthetic and biopolymers or their systems. Optically Active Polymers are related to problems of the same class, since optical activity is an inherent property of both natural macromolecules as well as a great variety of polymers synthesized in the Jast twenty years. Optical activity is a physical spectral property of chiral matter caused by asymmetrical configurations, conformations and structures which have no plane and no center of symmetry and consequently have two mirror image enantiomeric forms of inverse optical rotation. The racemic mixture of chiral enantiomers is optically inactive. The most common form of optical activity was first measured at a constant wavelength by the angle of rotation of linearly polarized light. More recently the measurements have been extended to the entire range of visible and attainable ultraviolet regions where electronic transitions are observed, giving rise to the ORD technique (Optical Rotatory Dispersion). The Cotton effects appear in the region of optically active absorption bands; outside of these bands the plain curve spectrum is also dependent on all the electronic transitions of the chromophores.
Download or read book Chirality in Liquid Crystals written by Heinz Kitzerow and published by Springer Science & Business Media. This book was released on 2001 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the main aspects of chirality in liquid crystals, and points out some of the open questions of current research. The chapters review the highlights of the important topics and questions.
Download or read book Chiroptical Molecular Switches written by Anne Marie Schoevaars and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bio Based Polymers and Composites written by Richard Wool and published by Elsevier. This book was released on 2011-08-30 with total page 641 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bio-Based Polymers and Composites is the first book systematically describing the green engineering, chemistry and manufacture of biobased polymers and composites derived from plants. This book gives a thorough introduction to bio-based material resources, availability, sustainability, biobased polymer formation, extraction and refining technologies, and the need for integrated research and multi-disciplinary working teams. It provides an in-depth description of adhesives, resins, plastics, and composites derived from plant oils, proteins, starches, and natural fibers in terms of structures, properties, manufacturing, and product performance. This is an excellent book for scientists, engineers, graduate students and industrial researchers in the field of bio-based materials. * First book describing the utilization of crops to make high performance plastics, adhesives, and composites * Interdisciplinary approach to the subject, integrating genetic engineering, plant science, food science, chemistry, physics, nano-technology, and composite manufacturing. * Explains how to make green materials at low cost from soyoil, proteins, starch, natural fibers, recycled newspapers, chicken feathers and waste agricultural by-products.
Download or read book Bionanocomposites for Packaging Applications written by Mohammad Jawaid and published by Springer. This book was released on 2017-11-21 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a unified overview of eco-friendly bionanocomposites on the basis of characterization, design, manufacture, and application. It also explores replacing conventional materials with bionanocomposites with a focus on their use in packaging applications. In addition, the book broadens readers’ insights by providing illustrations and tables summarizing the latest research on the packaging applications of different bionanocomposites. By offering a detailed account of this field of research and describing real-world applications, it enables researchers, scientists, and professionals in industry to develop a more informed understanding of the need for bionanocomposites in the development of green, biodegradable, and sustainable packaging applications.
Download or read book Introduction to Fluoropolymers written by Sina Ebnesajjad and published by William Andrew. This book was released on 2013-05-11 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Fluoropolymers demystifies fluoropolymers for a wide audience of designers, engineers, sales staff and managers. This important group of high-performance polymers has applications across a wide range of market sectors, including automotive, aerospace, medical devices, high performance apparel, oil & gas, renewable energy / solar photovoltaics, electronics / semiconductor, pharmaceuticals, and chemical processing. Dr. Ebnesajjad covers the history and applications of a wide variety of materials, including expanded polytetrafluoroethylene, polyvinyl fluoride, vinylidene fluoride polymers and fluoroelastomers, just to name a few. Properties and applications are illustrated by real-world examples as diverse as waterproof clothing, vascular grafts and coatings for aircraft interiors. The different applications of fluoropolymers show the benefits of a group of materials that are highly water-repellant and flame-retardant, with unrivalled lubrication properties and a high level of biocompatibility. Health and safety and environmental aspects are also covered throughout the book. Demystifies fluoropolymers for a broad audience of engineers in areas such as product design and manufacturing, as well as for non-engineers such as technical sales and management professionals Explains the potential of fluoropolymers for a wide range of applications across sectors such as aerospace, energy and medical devices Ideal for both recently qualified engineers and engineers with limited experience of fluoropolymers
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.
Download or read book Metallofoldamers written by Galia Maayan and published by John Wiley & Sons. This book was released on 2013-01-18 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallofoldamers are oligomers that fold into three-dimensional structures in a controlled manner upon coordination with metal ions. Molecules in this class have shown an impressive ability to form single-handed helical structures and other three-dimensional architectures. Several metallofoldamers have been applied as sensors due to their selective folding when binding to a specific metal ion, while others show promise for applications as responsive materials on the basis of their ability to fold and unfold upon changes in the oxidation state of the coordinated metal ion, and as novel catalysts. Metallofoldamers: From Helicates to Biomimetic Architectures describes the variety of interactions between oligomers and metal species, with a focus on non-natural synthetic molecules. Topics covered include: the major classes of foldamers and their folding driving force metalloproteins and metalloenzymes helicates: self-assembly, structure and applications abiotic metallo-DNA metallo-PNA and iDNA metallopeptides interactions of biomimetic oligomers with metal ions applications of metallofoldamers
Download or read book Hybrid Polymer Composite Materials written by Vijay Kumar Thakur and published by Woodhead Publishing. This book was released on 2017-06-03 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid Polymer Composite Materials: Applications provides a clear understanding of the present state of-the-art and the growing utility of hybrid polymer composite materials. It includes contributions from world renowned experts and discusses the combination of different kinds of materials procured from diverse resources. In addition, this volume from the four volume series provides deep insights on the potential of hybrid polymer composite materials for advanced applications. Provides a clear understanding of the present state-of-the-art and the growing utility of hybrid polymer composite materials Includes contributions from world renowned experts and discusses the combination of different kinds of materials procured from diverse resources Discusses their synthesis, chemistry, processing, fundamental properties, and applications Provides insights on the potential of hybrid polymer composite materials for advanced applications
