Download or read book Block Copolymer Adhesion Promoters Via Ring opening Metathesis Polymerization written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coupling agents based on functionalized block copolymers for bonding thermoset polymers to solid materials. These are polymers which possess at least two types of functional groups, one which is able to attach to and react with solid surfaces, and another which can react with a thermoset resin, which are incorporated as pendant groups in monomers distributed in blocks (typically two) along the backbone of the chain. The block copolymers in this invention are synthesized by living ring-opening metathesis polymerization.

Download or read book Functionalized Block Copolymers as Adhesion Promoters written by and published by . This book was released on 1995 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this work is to develop novel functionalized block copolymers to promote adhesion at inorganic substrate/polymer interfaces. We envision several potential advantages of functionalized block copolymers over small molecule coupling agents. Greater control over the structure of the interphase region should result through careful design of the backbone of the copolymer. The number of chains per area, the degree of entanglement between the copolymer and the polymer matrix, the number of sites per chain able to attach to the substrate, and the hydrophobicity of the interphase region can all be strongly affected by the choice of block lengths and the monomer sequence. In addition, entanglement between the copolymer and the polymer matrix, if achieved, should contribute significantly to adhesive strength. Our program involves four key elements: the synthesis of suitable functionalized block copolymers, characterization of the conformation of the copolymers at the interface by neutron reflectivity and atomic force microscopy, characterization of the degree of bonding by spectroscopy, and measurement of the mechanical properties of the interface. In this paper we discuss block copolymers designed as adhesion promoters for the copper/epoxy interface. We have synthesized a diblock with one block containing imidazole groups to bond to copper and a second block containing secondary amines to react with the epoxy matrix. We have also prepared a triblock copolymer containing a hydrophobic middle block. Below we describe the synthesis of the block copolymers by living, ring-opening metathesis polymerization (ROMP) and the first characterization data obtained by neutron reflectivity.

Download or read book Amine containing Block Copolymers written by and published by . This book was released on 1996 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Arylamine-containing diblock copolymers were prepared via ring- opening metathesis polymerization (ROMP) to afford well-defined phase- separated materials. Alteration of the functionaity in a block, as well as the size of the blocks, allowed for the synthesis of self- assembled monolayers on a copper surface. The arylamine-containing block exhibited a strong binding affinity for the copper surface as seen by neutron reflectivity experiments. In addition, neutron reflectivity data verifies the self-assembly of block copolymer monolayers normal to the copper surface. Block copolymers prepared in this manner allow for the preparation of a wide range of adhesives and corrosion resistant materials. The use of ring-opening metathesis polymerization is important because it permits the synthesis of a variety of functionalized block copolymers.

Download or read book Synthesis and Applications of Ring Opening Metathesis Polymerization Based Functional Block Copolymers written by Sanchita Biswas and published by . This book was released on 2010 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ring opening metathesis polymerization (ROMP) is established as one of the efficient controlled living polymerization methods which have various applications in polymer science and technology fields. The research presented in this dissertation addresses several applications of multifunctional well-defined norbornene-based block copolymers synthesized by ROMP using ruthenium-based Grubbs catalysts. These novel block copolymers were applied to stabilize maghemite nanoparticles, creating the superparamagnetic polymeric nanocomposites. The J-aggregation properties of the porphyrin dyes were improved via self-assembly with a customized norbornene polymer. Novel multimodal copolymer probes were synthesized for two-photon fluorescence integrin-targeted bioimaging. In Chapter 1 a brief overview of ROMP along with ruthenium metal catalysts and selected applications of the polymers related to this research is presented. Superparamagnetic maghemite nanoparticles are important in biotechnology fields, such as enhanced magnetic resonance imaging (MRI), magnetically controlled drug delivery, and biomimetics. However, cluster formation and eventual loss of nano-dimensions is a major obstacle for these materials. Chapter 2 presents a solution to this problem through nanoparticles stabiulized in a polymer matrix. The synthesis and chracterization of novel diblock copolymers, consisting of epoxy pendant anchoring groups to chelate maghemite nanoparticles and steric stabilizing groups, as well as generation of nanocomposites and their characterization, including surface morphologies and magnetic properties, is discussed in Chapter 2. In Chapter 3, further improvement of the nanocomposites by ligand modification and the synthesis of pyrazole-templated diblock copolymers and their impact to stabilize the maghemite nanocomposite are presented. Additionally, the organic soluble magnetic nanocomposites with high magnetizations were encapsulated in an amphiphilic copolymer and dispersed in water to assess their water stability by TEM. To gain a preliminary measure of biocopatibility of the micelle-encapsulated polymeric magnetic nanocomposites, cell-viability was determined. In Chapter 4, aggregation behaviors of two porphyrin-based dyes were investigated. A new amphiphilic homopolymer containing secondary amine moieties was synthesized and characterized. In low pH, the polymer became water soluble and initiated the stable J-aggregation of the porphyrin. Spectroscopic data supported the aggregation behavior. Two photon fluorescence microscopy (2PFM) has become a powerful technique in bioimaging for non-invasive imaging and potential diagnosis and treatment of a number of diseases via excitation in the near-infrared (NIR) region. The fluorescence emission upon two-photon absorption (2PA) is quadratically dependent with the intensity of excitation light (compared to the linear dependence in the case of one-photon absoprtion), offering several advantages for biological applications over the conventional one-photon absorption (1PA) due to the high 3D spatial resolution that is confined near the focal point along with less photodamage and interference from the biological tissues at longer wavelength (~700-900 nm). Hence, efficient 2PA absorbing fluorophores conjugated with specific targeting moieties provides an even better bioimaging probe to diagnose desired cellular processes or areas of interest The [alpha subscript v beta subscript 3] integrin adhesive protein plays a significant role in regulating angiogenesis and is over-expressed in uncontrolled neovascularization during tumor growth, invasion, and metastasis. Cyclic-RGD peptides are well-known antagonists of [alpha subscript v beta subscript 3] integrin which suppress the angiogenesis process, thus preventing tumor growth. In Chapter 5 the synthesis, photophysical studies and bioimaging is reported for a versatile norbornene-based block copolymer multifunctional scaffold containing biocompatible (PEG), two-photon fluorescent (fluorenyl), and targeting (cyclic RGD peptide) moieties. This water-soluble polymeric multi scaffold probe with negligible cytotoxicity exhibited much stronger fluorescence and high localization in U87MG cells (that overexpress integrin) compared to control MCF7 cells. The norbornene-based polymers and copolymers have quite remarkable versatility for the creation of advanced functional magnetic, photonic, and biophotonic materials.

Download or read book Synthesis and Self assembly of Conjugated and Biomimetic Polymers and Block Copolymers Via Ring opening Metathesis Polymerization written by Hassan Said Bazzi and published by . This book was released on 2003 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Synthesis of Modular Block Copolymers written by Mary Nell Higley and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel methodology has been developed for the formation of block copolymers that combines ring-opening metathesis polymerization (ROMP) with functional chain-transfer agents (CTAs), functional chain-terminators (CTs) and self-assembly. Telechelic homopolymers of cyclooctene derivatives that are end-functionalized with hydrogen-bonding or metal-coordination sites are formed via the combination of ROMP with a corresponding functional CTA. These telechelic homopolymers are fashioned with a high control over molecular weight and without the need for post-polymerization procedures. The homopolymers undergo fast and efficient self-assembly with their complement homopolymer or small molecule analogues to form block copolymer architectures. The block copolymers have similar association constants to small molecule analogues described in the literature, regardless of size or the nature of the complementary unit or the polymer side-chain. The ROMP of side-chain functionalized norbornene polymers is coupled with functional CTs to produce block copolymer with main- and side-chain self-assembly sites. Combinations of these norbornene polymers with their complement polymer via self-assembly produce non-covalent AB type block copolymers fast and efficiently. ABA type block copolymers are realized by combining the difunctional homopolymer formed via the CTA pathway with the CT synthesized mono-functional polymer. These polymers show similar association constants regardless of the sequence of polymer formation.

Download or read book Polymer polymer Adhesion Promotion by Block copolymer Addition written by Ralf Brian Mason and published by . This book was released on 2002 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Conjugated Block Copolymers Composed of Dithienyl Cyclopentadithiophene Via Ring Opening Metathesis Polymerization written by Yun-Yung Lu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Official Gazette of the United States Patent and Trademark Office written by United States. Patent and Trademark Office and published by . This book was released on 1997 with total page 1552 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Official Gazette of the United States Patent and Trademark Office written by and published by . This book was released on 1997 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Organic Photoredox mediated Ring opening Metathesis Polymerization Through Expanded Functionalities of Initiators and Monomers written by Pengtao Lu and published by . This book was released on 2019 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ring-opening metathesis polymerization (ROMP), which is derived from transition-metal-based olefin metathesis, has evolved into one of the most prevalent technologies for making functional polymeric materials. Due to the nature of this polymerization method, the metal alkylidene remains covalently bound to the polymer chain end until the introduction of various quenchers to terminate the polymerization. However, the removal of resultant metal by-products requires multiple purification steps. Recently, our group pioneered establishment of organic photoredox-mediated ROMP (o-ROMP), which is driven by the motivation of developing a metal-free alternative to traditional ROMP. This thesis aims to contribute to the study of o-ROMP by describing our investigations in the field, with a particular emphasis on expanding scopes of functional initiators and monomers. Chapter 1 is an introduction to o-ROMP, which start with explanation of community interests on developing organic photoredox-mediated controlled polymerization (OPCP). The general mechanisms of these novel polymerizations, including the properties of various organic photoredox catalysts, will be reviewed first. The flowing discussion will focus on different kinds of established OPCPs, which emphasizes on unique scopes for each specific methods. We will end up the introduction part with our previous efforts on developing o-ROMP. Chapter 2 begins with our initial attempts on testing the feasibility of grafting o-ROMP from small-molecular multitopic initiators. The successful combination of this multidirectional growth mode with the design of macroinitiators facilitate preparation of polyether-based triblock copolymer and polystyrene-based graft copolymer, which are both acid cleavable. Chapter 3 describes our recent efforts on expanding the scope of macroinitiator towards polyesters and polycarbonates, which are derived from organocatalyzed ring-opening polymerization (o-ROP). Grafting from bifunctional initiators in one pot, stepwise o-ROP and o-ROMP succeed in making biocompatible block copolymers via a completely metal-free pathway. Finally, Chapter 4 discusses our ongoing efforts in the expansion of monomer scopes, aiming to make functional polymers solely through o-ROMP strategy. The successful adoption of those deprotection-free functional monomers not only make it possible to enable post-polymerization modification, but also provide opportunity to control chain architectures of resulted polymer.

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 1996 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Maro Polymer Notes written by and published by . This book was released on 1997 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure property Relationships in Novel Polymers and Block Copolymers from Ring opening Metathesis Polymerization written by John Paul Bishop and published by . This book was released on 2011 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ring opening metathesis polymerization derived block copolymers bearing chelating ligands synthesis metal immobilization and use in hydroformylation under micellar conditions written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Sequence controlled Copolymers Via Ring opening Metathesis Polymerization of Norbornene Derivatives written by Dennis Barther and published by . This book was released on 2022* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.