[PDF] Development Of Novel Functionalized Bis Nitroxide Initiators For The Preparation Of Designed Polymers eBook

Author : Didier Gigmes
Publisher : Royal Society of Chemistry
Page : 512 pages
File Size : 12,3 MB
Release : 2016
Category : Science
ISBN : 1782620613

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The first book dedicated to nitroxide-mediated polymerization and covers the history and development of NMP, as well as current techniques of academic and industrial interest.

Author : RI Chen
Publisher :
Page : 0 pages
File Size : 15,22 MB
Release : 2023
Category :
ISBN :

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Highly functionalized polymers represent a broad family of polymers with multiple functionalities attached to each repeat unit in the backbone. These can be small molecule functional groups or polymer sidechains grown or grafted from these functional groups. The latter leads to a class of polymers defined as comb polymers. This type of structure enforces a highly stretched conformation of the polymer backbone and imparts unique properties due to low inter chain entanglement and low entropic penalty for self-assembly. The comb polymers have a diverse set of architectures and compositions with potential applications in surface modification, resin formulation and nanopatterning. To realize this potential, efficient, versatile and easy-to-handle synthetic methods need to be constantly evolved. This dissertation focuses on the synthesis of comb polymers based on a new monomer and the application of multi-component reactions to reduce synthetic complexity. The first part of this dissertation focuses on the design of a benign formamide monomer capable of undergoing isocyanide-based multi-component reaction. The synthesis, polymerizability, reactivity and stability of this monomer is studied, along with its utility in the synthesis of comb polymers. Specifically, a difunctional polymerizable initiator (Y-inimer) that can be used for two tandem controlled polymerizations is designed from the formamide monomer. The utility of this Y-inimer is demonstrated through the synthesis of a comb polymer with 1:1 ratio of A and B chains, and A/B mixed polymer brushes from a substrate where intimate contact between the A and B chains is beneficial for exploring polyelectrolyte behavior. Finally, a comb polymer-based block copolymer additive is explored for synergistically improving the toughness and strength of a 3D printable epoxy resin. The main contribution of this dissertation lies in the 1) design of benign monomer that can be used in isocyanide-based multicomponent reactions to design highly functional polymers, without having to directly handle the isocyanide, 2) development of a dualfunctional polymerizable initiator for the synthesis of comb polymers with exact 1:1 ratio of A and B sidechains, and 3) development of a comb polymer additive for toughening of epoxy resin without loss of modulus or rheological properties.

Author : Amelia Marie Anderson
Publisher :
Page : 0 pages
File Size : 44,75 MB
Release : 2010
Category :
ISBN :

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Decades of research in the area of metal-catalyzed olefin polymerization, since the initial discoveries by Ziegler and Natta in the 1950s, has lead to the development of a wide variety of transition metal catalysts as well as numerous polymer architectures. Although early work in the field focused on heterogeneous catalysis, Kaminsky's discovery of the scavenger/activator methylaluminoxane in 1980 facilitated a renaissance in the area of homogeneous catalysts. Today, many commercial polyolefin materials are still limited to linear homopolymers, random copolymers, or blends thereof. Therefore, our efforts have focused on the endfunctionalization and random incorporation of polar functional groups into polyolefins to produce polymers with improved properties and more complex architectures than traditional linear polymers. Initial work in this area focused on the development of well-defined long-chain branched polymers from end-functionalized polypropylene. Although many star polymers have been produced using anionic, cationic and radical methods, semicrystalline polypropylene materials with similar structures from coordinationinsertion polymerization were not known. Using a non-living bis(phenoxyimine)titanium catalyst, allyl-terminated syndiotactic polypropylene was produced and utilized in the production of alcohol-, azide- and amine-terminated polymers. These end-functionalized macromolecules were employed in the synthesis of a variety of well-defined branched polymers including star, miktoarm star and H- polymers. In an effort to produce branched polyolefin materials with high molecular weight, a norbornene-terminated polymer was synthesized from the allyl-terminated syndiotactic polypropylene. Using ring-opening metathesis polymerization, a number of high molecular weight polypropylene comb polymers were produced. All of the branched, syndiotactic polypropylene materials were analyzed further in an effort to related branching with observed polymer properties. To produce polyolefins with improved properties, a series of random copolymers derived from propylene and a polar, hydrogen bonding monomer were produced using Ni(II) [alpha]-diiminecatalysts. By varying the reaction temperature, hydrogen bonding polypropylene materials with a range of microstructures were produced. At high reaction temperatures, regioirregular, amorphous polypropylene was obtained, whereas, decreasing reaction temperature lead to highly regioregular, isotactic polypropylene. Utilizing the living nature of the Ni(II) [alpha]-diiminecatalysts, a series of triblock copolymers containing hydrogen bonding moieties in the midblock were also produced. The mechanical properties of all materials were investigated and generally observed to improve upon incorporation of small amounts (~1%) of the ureidopyrimidinone. For the branched and hydrogen bonding polymer reported herein, functionalization of polypropylene allowed for the synthesis of new polyolefin architectures.

Author : Y. Imamoglu
Publisher : Springer
Page : 354 pages
File Size : 46,66 MB
Release : 2003-11-30
Category : Science
ISBN : 9781402015700

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A comprehensive discussion of the theory, practice and application of catalytically active transition metal species and their application in the production of specialist polymeric materials. The material is presented in a progressive manner, suitable for non-experts and those seeking an introduction to the field. The bibliographies supplied are complete and up to date, making the book an indispensable guide to the primary literature for the more theoretical background to the topics discussed. After a comprehensive discussion of initiating systems for speciality chemical synthesis the book goes on to deal with a wide range of topics in materials science, including: alkenamers, polyacetylenes, industrial applications and liquid rocket engine fuels.

Author : Omari E Ansong
Publisher :
Page : 153 pages
File Size : 35,97 MB
Release : 2008
Category :
ISBN :

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A number of nitroxide adducts and N-acyloxytrialkylammonium salts were prepared, isolated, characterized and evaluated as initiators for the controlled and living free radical polymerization of methacrylate and dimethacrylate monomers under mildly thermal and photochemical conditions. The initiators and polymerization methods that were developed could potentially be used for improving resins employed in dental applications. Using very easy synthesis strategies, the following nitroxide initiators were prepared in high purity, isolated and characterized: 1-Benzoylperoxy-2,2,6,6-tetramethyl-piperidine (BPO/TEMPO), 1-(2'-Cyano-2'-propoxy)-2,2,6,6-tetramethylpiperidine (AIBN/TEMPO), 1,1-ditertbutyl-1-(1-methyl-1-cyanoethoxy)-amine (AIBN/DBN), 1,1-ditertbutyl-1-(benzoylperoxy)-amine (BPO/DBN) and 2,2,6,6,-tetramethyl-4-oxo-1-(1-methyl-1-cyanoethoxy)-piperidine (AIBN/4-OXO-TEMPO). Using H2SO4 additive and an improved unimolecular initiation in nitroxide mediated polymerization, living and controlled polymerization of methyl methacrylate (MMA), tri-ethylene glycol dimethacrylate (TEGDMA) and ethoxylated bisphenol A dimethacrylate (EBPADMA) were accomplished, for the first time ever for most of the initiators. Linear polymers (PMMA) were produced in high yield (93 %) under mildly thermal conditions (T = 70 oC) and with excellent attributes: (PDI = 1.04-1.26), Mn (87000), Tg (122-128 oC), Td (290-410 oC). Highly crosslinked polymers, poly(TEGDMA) and poly(EBPADMA), were produced in high yield (100 %) with Td (350-400 oC). The initiators were stable for a year and half at 0 oC. Two routes were investigated for the preparation of N-acyloxytrialkylammonium salts. The more efficient of these routes was used to make several novel analogs of the salts. The salts were evaluated for the free radical polymerization of MMA, TEGDMA and EBPADMA under mildly thermal (T = 60 oC) conditions with and without H2SO4 additive. Polymerization rate, yield and polymer attributes all improved upon application of H2SO4 additive. PMMA was produced with excellent attributes (PDI = 1.01-1.06), Mn (96,000-122000), Td (330-385) and Tg (127-134). Highly crosslinked poly(TEGDMA) and poly(EBPADMA) were produced with Td ranges of 300-374 oC and 375-411 oC respectively.

Author : Arun Kumar Nandi
Publisher : Royal Society of Chemistry
Page : 457 pages
File Size : 16,57 MB
Release : 2021-06-18
Category : Science
ISBN : 1788019687

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There is an immense variety of research on polymer functionalized graphene (PFG). Functionalization of graphene is necessary for improvement of the compatibility with polymers. Applications of these graphene polymer hybrids include in chemical and biological sensing, photovoltaic devices, supercapacitors and batteries, dielectric materials and drug/gene delivery vehicles. This book will shed light on the synthesis, properties and applications of these new materials, covering two methods (covalent and noncovalent) for producing polymer functionalized graphene. Chapters cover physical, optical, mechanical and electronic properties, applications of polymer functionalized graphene in energy harvesting and storage, and uses in biomedicine and bioengineering. Written by an expert in the field, Polymer Functionalized Graphene will be of interest to graduate students and researchers in polymer chemistry and nanoscience.