Download or read book Syntheses and Functionalization of Block Copolymers Based on Polystyrene Block Poly 4 Vinylpyridine and Polystyrene Block Polyisoprene written by SIJIAN. HOU and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Syntheses and Functionalization of Block Copolymers Based on Polystyrene-block-poly(4-vinylpyridine) and Polystyrene-block-polyisoprene" by 侯斯健, Sijian, Hou, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3124033 Subjects: Copolymers - Synthesis

Download or read book Syntheses and Functionalization of Block Copolymers Based on Polystyrene block poly 4 vinylpyridine and Polystyrene block polyisoprene written by Sijian Hou and published by . This book was released on 1999 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Micelles written by Shin-ichi Yusa and published by MDPI. This book was released on 2018-04-20 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Polymer Micelles" that was published in Polymers

Download or read book Synthesis and Properties of the First Macrocyclic Polystyrene polydimethylsiloxane Block Copolymers written by Rui Yin and published by . This book was released on 1993 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Macrocyclic and Catenated Polystyrene poly 2 vinylpyridine Block Copolymers written by Yaodong Gan and published by . This book was released on 1995 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anionic Synthesis of Block Copolymers for Photonics Applications written by Camila Garcés Cortés and published by . This book was released on 2010 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Anionic synthesis of well-defined polystyrene-block-polyvinylpyridine copolymers required the use of special conditions including lithium chloride and 1,1-diphenylethylene as additives, low temperature of reaction ( -78 °C), highly diluted monomer at -78 °C and efficient stirring (Morton-type, creased reactor). Low molecular weight polystyrene-block-poly(2-vinylpyridine) copolymers (M[subscript n] = 6000 g/mol) were synthesized with average -molecular weights in agreement with the theoretically calculated M[subscript n]s and narrow M[subscript w]/M[subscript n]s (less than or equal to 1.1). Polystyrene-block-polyvinylpyridine copolymers were selected for the favrication of uniformly dispersed metal oxide nanoparticles (cobalt and iron oxides) due to the coordinating ligand character of the vinylpyridine units. The incorporation of the inorganic salts (1 mol-eq of inor. salt per mol of vinylpyridine units) was 57 wt% when polystyrene-block-poly(2-vinylpyridine-co-4-vinylpyridine) (M[subscript n] = 59,000 g/mol, M[subscript w]/M[subscript n] = 1.09, f[subscript v PVP] = 0.19) was used and 18 wt% when polystyrene-block-poly(2-vinylpyridine) (M[subscript n] = 39,000 g/mol, M[subscript w]/M[subscript n] = 1.07, f[subscript v PVP] = 0.14) was used. The end-capping reaction of polymeric chain-ends with 1,1-diphenylethylene (DPE) was studied using 2D NMR spectroscopic and MALDI-TOF mass spectrometric analyses. Oligomerization of DPE was observed using a 15-fold excess of DPE in the end-capping of poly(butadienyl)lithium (M[subscript n] = 2,200 g/mol, M[subscript w]/M[subscript n] = 1.06) but not in the case of poly(styryl)lithium (M[subscript n] = 2,000 g/mol, M[subscript w]/M[subscript n] = 1.02). Although oligomerization of DPE has been previously reported in the synthesis of 1,1-diphenylhexyllithium (6-11% oligomer with 5.4-fold excess of DPE), there are no studies showing the presence of DPE oligomer in the end-capping reaction of polymeric living carbanions. Additionally, the synthesis of poly(para-phenylene) has been studied using different precursor polymers [poly(1,3-cyclohexadienes) (M[subscript n] = 1,600 and 3,100 g/mol, M[subscript w]/M[subscript n] - 1.1 and 1.03) and poly(2-phenyl-1,3-cyclohexadiene) (M[subscript n] = 10,000 g/mol, M[subscript w]/M[subscript n] = 1.27) homopolymers] and dehydrogenating agents [2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil)] (4 mol-eq of benzoquinone per mol of cyclohexadiene unit). The results indicate that the efficiency of the dehydrogenation reaction was limited by precipitation of the polymer in the case of poly(1,3-cyclohexadiene). The advantage of using poly(2-phenyl-1,3-cyclohexadiene) lies in the formation of a soluble poly(2-phenyl-para-phenylene) with thermal stability and mechanical properties similar to those of the insoluble poly(para-phenylene) (TGA[subscript res][1000 °C] = 40.2%)."--Abstract.

Download or read book written by and published by . This book was released on 1957 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Applications of Copolymers written by Anbanandam Parthiban and published by John Wiley & Sons. This book was released on 2014-06-23 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the reactivity of monomers is crucial in creating copolymers and determining the outcome of copolymerization. Covering the fundamental aspects of polymerization, Synthesis and Applications of Copolymers explores the reactivity of monomers and reaction conditions that ensure that the newly formed polymeric materials exhibit desired properties. Referencing a wide-range of disciplines, the book provides researchers, students, and scientists with the preparation of a diverse variety of copolymers and their recent developments, with a particular focus on copolymerization, crystallization, and techniques like nanoimprinting and micropatterning.

Download or read book Synthesis Characterization and Self assembly of Amphiphilic Block Copolymers written by Xiaojun Wang and published by . This book was released on 2012 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a review on state-of-the-art research of well-defined charged block copolymers, including synthesis, characterization, bulk morphology and self-assembly in aqueous solution of amphiphilic block polyelectrolytes. In Chapter 1, as a general introduction, experimental observations and theoretical calculations devoted towards understanding morphological behavior in charged block copolymer systems are reviewed along with some of the new emerging research directions. Further investigation of charged systems is urged in order to fully understand their morphological behavior and to directly target structures for the tremendous potential in technological applications. Following this background, in Chapters 2, 3, 4 and 5 are presented the design and synthesis of a series of well-defined block copolymers composed of charged and neutral block copolymers with full characterization: sulfonated polystyrene-b-fluorinated polyisoprene (sPS-b-fPI) and polystyrene-b-sulfonated poly(1,3-cyclohexadiene) (PS-b-sPCHD). Their bulk morphological behaviors in melts and self-assembly of sPS-b-fPI, PS-b-sPCHD in water were investigated. Some unique behaviors of sPS-b-fPI were discovered. The mechanisms for formation of novel nanostructures in aqueous solution are discussed in details in Chapter 4. Spherical and vesicular structures were formed from strong electrolyte block copolymers, e.g. PS-bsPCHD. Detailed light scattering and transmission electron microscopy were applied to characterize these structures. The abnormal formation of vesicles as well as microstructure effects on self-assembly is discussed in Chapter 5. In Chapter 6, we describe the successful synthesis of a well-defined acid-based block copolymers containing polyisoprene while maintaining the integrity of the functionality (double bonds) of polyisoprene. A general purification method is also presented in order to remove homo polyisoprene, polystyrene, and PS-b-PI in the di-, and tri-block copolymers. The self-assembly of PS-b-PI-b-PAA triblock terpolymers was studied in order to form multicompartmental structures in aqueous environments. In the last Chapter 7, detailed synthesis and characterization of a novel conjugate: poly(L-leucine) grafted hyaluronan (HA) (HA-g-PLeu) are presented. This work describes a new method to synthesize HA-g-PLeu via a "grafting onto" strategy. Due to the amphiphilic nature of this graft copolymers, a "local network" formed by self-assembly which was characterized by atomic force microscopy and light scattering. The secondary structure of the polypeptide was revealed by circular dichroism.

Download or read book Synthesis of Poly paraphenylene Vinylene Polystyrene based Rod coil Block Copolymer by Atom Transfer Radical Polymerization Toward a Self organized Lamellar Semiconducting Material written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom transfer radical polymerization (ATRP) was used as a versatile route to well-defined poly(diethylhexyl-p-phenylenevinylene-b-styrene) (PPV-b-PS) semiconducting block copolymers. For this purpose, original conjugated macroinitiators were synthesized from DEH-PPV and further used for the copolymerization reaction. The microphase-separated morphologies obtained with the semiconducting PPV-b-PS block copolymer fulfill the basic structural requirements required to build efficient organic photovoltaic devices.

Download or read book Hydrophilic 60 fullerene End capped Polystyrene block poly ethylene Oxide Copolymers written by Xiaochen Li and published by . This book was released on 2013 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, "shape amphiphiles" has attracted great attention. "Shape amphiphiles" usually refer to molecules possessing differences in the shape of the molecular moieties. It is found that these shape amphiphiles can self-assemble into diverse structure in solution, which is similar as small molecule surfactant and block copolymer, but has distinct molecular designs and topologies. Shape and interactions are two crucial factors to detect the self-assembly of these models. The previous research in our group has revealed that the giant molecular shape amphiphiles based on polystyrene-hydrophilic [60]Fullerene (AC60) conjugates can self-assemble into various structure. In this thesis, a comprehensive study on the synthesis and self-assembly behaviors in solution of a new giant molecular shape amphiphile, namely, the hydrophilic [60]Fullerene (AC60) tethered with polystyrene-b-poly(ethylene oxide) block copolymer (PEO-b-PS-AC60) has been investigated. The synthesis highlighted the Bingel-Hirsch cyclopropanation reaction for C60 surface functionalization and the Huisgen 1,3-dipolar cycloaddition of azide-alkyne, which is also well-known as "click" reaction, between alkyne functionalized AC60 and azide functionalized diblock copolymer PEO-b-PS to give rise to shape amphiphiles with precisely defined surface chemistry and molecular topology. For the block copolymer, the molecular weight of PEO was fixed at 2K/mol, a series of block copolymer PEO45-b-PS[subscript n] with different chain length of PS and narrow molecular weight distribution were synthesized by Atom Transfer Radical Polymerization (ATRP). The chemical structure of all intermediate and final products were fully confirmed and characterized by proton nuclear magnetic resonance(1H-NMR), carbon nuclear magnetic resonance (13C-NMR), Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass, Fourier transform infrared spectroscopy (FTIR) and size-exclusion chromatography (SEC). The self-assembling behaviors of shape amphiphiles as-prepared in solution was investigated by using 1,4-dioxane/DMF mixture as the common solvent and water as the selective solvent. As revealed by transmission electron microscopy (TEM), these shape amphiphilies exhibit versatile self-assembled micellar morphophogies, which can be tuning by changing initial molecular concentration or chain length of PS. Finally, the critical water concentration (CWC) of all shape amphiphiles as-prepared was determined by static light scattering (SLS) experiments. The results indicate that the value of (CWC) is dependent on the chain length of PS.

Download or read book Synthesis and Characterization of Ionically Bonded Diblock Copolymers written by Lei Feng (Chemical engineer) and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers consist of two or more incompatible polymer chains linked by covalent bonds. These block copolymer can separate into nanometer sized domains whose morphology depends upon the size of the block and interactions between them. The properties of block copolymers can be modified and potentially improved by introducing noncovalent interactions to replace covalent linkages between blocks to form supramolecular block copolymers. These kinds of materials combine the microphase separation inherent to block copolymers with the facile synthesis of supramolecular materials thereby affording new and unique materials. This dissertation focuses on synthesis and characterization of PS-b-PMA block copolymers with ion-pair junctions.Firstly, the chain-end sulfonated polystyrene ([omega]-sulfonated PS) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization and postpolymerization modification. In the postpolymerization modification two methods were investigated: in the first one, the polymer was converted to a thiol-terminated polymer by aminolysis. Then a sulfonic acid end-group was produced then by oxidation of the thiol end-group with m-chloroperoxybenzoicacid (m-CPBA); in the second method, the RAFT-polymerized polymer was directly sulfonated by oxidation with m-CPBA. After purification by column chromatography, [omega]-sulfonated PS was obtained by both methods with greater than 95% end-group functionality as measured by titration. The sulfonic acid end-group could be neutralized with various ammonium or imidazolium counter ions through acid-base or ionic metathesis reactions. These polymers with ionic end-group can be used as model supramolecular building blocks.Secondly, ammonium end functionalized polymethylacrylate (PMA) was synthesized directly by RAFT polymerization using functional RAFT agent. Then chain-end sulfonated polystyrene and ammonium end functionalized polymethylacrylate (PMA) were used to synthesize A-B block copolymers by two different methods: the first method was by mixing two oppositely charged end group functionalized polymers; the second method was to ionically bond a RAFT agent to the chain end of an end sulfonated polymer to generate a supramolecular macro RAFT agent then an A-B block copolymer was prepared by RAFT polymerization using supramolecular macro-RAFT agent. The polymerization kinetics were investigated and the molecular weight and the chemical structure of the block copolymers were characterized by 1H-NMR and SEC. The results show that the ion-bonded supramolecular block copolymer, PS-PMA, have been successfully prepared with controlled molecular weight and narrow distribution.Thirdly, the morphology of the ion-bonded supramolecular PS-PMA diblock copolymers were investigated by small-angle X-ray scattering (SAXS) and rheological techniques. Several covalently bonded PS-PMA block copolymers were synthesized by RAFT polymerization and their micro domain structures and rheology behaviors were also investigated. The results showed that the electrostatic interactions between the end ion groups are able to overcome the thermodynamic repulsion of two blocks result in the formation of diblock copolymers with similar behaviors and morphology of traditional covalent bonded diblock copolymers and their micro domain structures remain to high temperatures.

Download or read book Synthesis and Self assembly of Advanced Bottlebrush Block Copolymers written by Justin Bolton and published by . This book was released on 2012 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the grafting-from approach, three novel well-defined bottlebrush block copolymers were synthesized using various controlled polymerization techniques. Resulting macromolecules were characterized by GPC and 1H NMR and then self-assembled into nanostructured materials for further characterization. Asymmetric polystyrene-polylactide (PS-PLA) bottlebrush block copolymers have been shown to self-assemble into a cylindrical morphology with large domain spacings. PLA cylinders can be selectively etched out of the shear-aligned polymer monoliths to generate nanoporous materials with an average cylindrical pore diameter of 55 nm. The remaining bottlebrush backbone provides a functional, hydrophilic coating inside the nanopores. This methodology significantly expands the range of pore sizes attainable in block copolymer based nanoporous materials.^A polystyrene-poly(methyl methacrylate) (PS-PMMA) bottlebrush block copolymer with asymmetric branches was synthesized by grafting from a symmetrical backbone containing a novel dual vinyl initiation system and characterized by atomic force microscopy (AFM) and small-angle x-ray scattering (SAXS). The block copolymer backbone was prepared by sequential reversible addition-fragmentation chain transfer (RAFT) copolymerization of solketal methacrylate and 2-(bromoisobutyryl)ethyl methacrylate (BIEM). From the poly(BIEM) segment, PMMA branches were grafted by atom transfer radical polymerization (ATRP). Solketal groups were then subjected to hydrolysis and functionalized with a RAFT agent. Subsequently, from RAFT sites of the poly(SM) segment, polystyrene branches were grafted to yield the final bottlebrush block copolymer.^The resulting polymer was found to have a vertically oriented cylindrical morphology by AFM with an average cylinder diameter of 45 nm; morphology was also confirmed by SAXS analysis. A novel polylactide-poly(methyl methacrylate)-polystyrene (PLA-PMMA-PS) triblock bottlebrush block copolymer was synthesized from a triblock backbone employing ATRP, RAFT and ROP techniques. Novel 5-TMS-4-pentyn-1-ol methacrylate (TPYM) with protected alkyne functionality was developed and characterized as a homopolymer. Click chemistry was used to introduce RAFT groups along the homopolymer backbone. Subsequently, PS branches were grafted from RAFT initiators along the backbone. A well-defined poly(SM-b-BIEM-b-TPYM) backbone was synthesized followed by grafting of PMMA brushes from the BIEM segment by ATRP.^Post PMMA grafting, the ATRP end groups were removed and the TMS group was deprotected to allow functionalization of the alkyne with an azido terminated RAFT agent by way of Huisgen 1,3-dipolar cycloaddition. From the RAFT sites, PS was grafted followed by deprotection of the hydroxyl functionality of the SM block. Resulting liberated hydroxyls were used to initiate PLA grafts, yielding the final well-defined triblock bottlebrush block copolymer (PLA-PMMA-PS).

Download or read book Synthesis Morphology and Properties of Rod coil Block Copolymers Poly fluorene block poly 4 vinylpyridine written by 孫翰笙 and published by . This book was released on 2009 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Morphology Characterization of Different Architecture of Amphiphilic Block Copolymers Polystyrene block poly 3 trimethoxysilyl propyl Methacrylate and Polystyrene block poly 2 dimethylamino ethyl Methacrylate written by 徐榮慶 and published by . This book was released on 2007 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Block Copolymers written by Nikos Hadjichristidis and published by John Wiley & Sons. This book was released on 2003-04-28 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers may be classified as either homopolymers, consisting of one single repeating unit, or copolymers, consisting of two or more distinct repeating units. Block copolymers contain long contiguous blocks of two or more repeating units in the same polymer chain. Covering one of the hottest topics in polymer chemistry, Block Copolymers provides a coherent overview of the synthetic routes, physical properties, and applications of block copolymers. This pioneering text provides not only a guideline for developing synthetic strategies for creating block copolymers with defined characteristics, but also a key to the relationship between the physical properties of block copolymers and the structure and dynamics of materials. Covering features of the chemistry and physics of block copolymers that are not found in comparable texts, Block Copolymers illustrates the structure-activity relationship of block copolymers and offers suggestions for the design of specific applications. Divided into five sections-Block Copolymers includes chapters on: * Block Copolymers by Chemical Modification of Precursor Polymers * Nonlinear Block Copolymers * Adsorption of Block Copolymers at Solid-Liquid Interfaces * Theory of Block Copolymer Segregation * Phase Transformation Kinetics * Block Copolymer Morphology * Block Copolymer Dynamics Polymer chemists, physicists, chemical engineers, and materials scientists, as well as graduate students in polymer science, will find Block Copolymers to be an invaluable text.

Download or read book Synthesis of Block Copolymers Containing Polystyrene and Polysiloxane Segments written by Adrian K. deKrom and published by . This book was released on 1994 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: