| Covalent Percolation and Gold Templating of Carbon NanoTubes Network in Polymer Nanocomposites for Novel Mechanical, Electrical, and Optical Properties. Taiwain - US AFOSR Nanoscience Initiative |
26 MAR 2008 |
71 pages |
| Authors:
Arnold C. Yang; NATIONAL TSING HUA UNIV HSINCHU (TAIWAN) DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
 | The interactions between individual polymer chains with embedded carbon nanotubes (CNTs) in nanocomposites were investigated by using two model polymer systems, polystyrene and poly(phenylene oxide) representing respectively the ductile and brittle polymers, with surface-grafted multiwalled CNTs. |
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| Chemoprevention Against Breast Cancer with Genistein and Resveratrol |
01-Mar-2008 |
47 pages |
| Authors:
Timothy G Whitsett; ALABAMA UNIV IN BIRMINGHAM
|
| Breast cancer remains a destructive disease despite new therapeutics. It is well accepted that environmental factors can play an important role in determining one's future risk of the disease. We believe that two natural polyphenols, genistein (a component of soy) and resveratrol (a component of grapes and red wine), can suppress mammary carcinogenesis. We and others have clearly shown mammary-protective effects against chemically-induced cancer. This project aimed to elucidate mechanisms ... |
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| Tunable Multicolor Electroluminescent Polymer Devices for Full Color Displays |
16 AUG 1999 |
4 pages |
| Authors:
Samson A. Jenekhe; Xuejun Zhang; ROCHESTER UNIV NY DEPT OF CHEMICAL ENGINEERING
|
| Efficient light emitting diodes (LEDs) of various colors and suitable methods of their pixelation are essential to incorporating polymer LEDs into full color display systems. We have developed polymer/polymer heterojunction LEDs that exhibit multicolor emission which is tunable by the bias voltage. These LEDs are based on poly(p-phenylenevinylene) (PPV)/n-type polymer structures. ITO/PPV/polyquinoiine/Al diodes fabricated under ambient air environment had a turn-on voltage of 3.5 V, luminance levels of over 800 ... |
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| Charge Transfer Polymers as Ultrafast Holographic Materials |
1999 |
11 pages |
| Authors:
Alan J. Heeger; CALIFORNIA UNIV SANTA BARBARA INST FORPOLYMERS AND ORGANIC SOLIDS
|
| A summary of the significant scientific accomplishments that resulted from research supported under AFOSR F49620-99-1-0031 is included in this Final Technical Report with emphasis on the following specific areas: (i) Time Resolve Forster Energy Transfer in Polymer Blends (ii) Ultrafast Detection of Charged Photocarriers in Conjugated Polymers (iii) Photophysics of poly(2,3-diphenyl-5- hexyl-phenylene vinylene (iv) Singlet Exciton Binding Energy in Poly(phenylene vinylene) (v) Excitation Spectrum for Ultrafast Photogeneration of Charged Solitons ... |
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| Novel Macromolecular Materials for Electronic and Optical Applications |
OCT 1997 |
32 pages |
| Authors:
Yi Pang; CLARK ATLANTA UNIV GA DEPT OF CHEMISTRY
|
| A series of thiophene containing poly(arylene ethynylene)s have been synthesized and their molecular structures and PL properties have been characterized. A convenient synthetic route has been developed to prepare bis(3- alkylthienyl)ethyne (5) in high yield. Various attempts have been made to use (5) as an essential building block for developing novel poly(arylene ethynylene) materials. Regioregular poly(3-hexyl-2,5- thienylene ethynylene)s (P3HTE) have been synthesized in order to compare the steric interaction in ... |
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| Interface Control of Polymer Based Light Emitting Devices |
20 SEP 97 |
14 pages |
| Authors:
A. J. Epstein; Y. Z. Wang; D. D. Gebler; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
|
| Bilayer and multilayer polymer structures provide opportunities for new photophysics and new types of light emitting devices. Photoluminescent and electroluminescent studies of bilayer heterojunctions formed from a poly(pyridyl vinylene phenylene vinylene) (PPyVPV) derivative and poly(vinyl carbazole) (PVK) show an emission peak which cannot be ascribed to either the PPyVPV derivative of PVK layer. Through studies of absorption and photoluminescence excitation (PLE) spectra we demonstrated that the additional feature results from ... |
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| Low Energy Photophysics of Phenylene-Based Strapped Copolymers |
20 SEP 97 |
10 pages |
| Authors:
A. J. Epstein; N. V. Piskun; I. V. Lebedenko; S. W. Jessen; T. L. Gustafson; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
|
| We present the absorption and emission properties of the phenylene- based copolymers, poly (pyridyl vinylene-phenylene vinylene) (PPyVPV), poly (thienylene p-phenylene) (PTpP) and poly (dithienylene p-phenylene) (PDTpP), which incorporate 'Straps' to bridge the 2 and 5 positions of the phenyl rings. The absorption and luminescence properties of the PPyvPV polymers are morphology dependent. The absorption's maxima are at -3.0 eV, with the films having absorption edges that tail into the IR. ... |
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| Intrinsically Trapped Triplet Excitons in pi-Conjugated Polymers |
20 SEP 97 |
16 pages |
| Authors:
J. Partee; J. Shinar; S. W. Jessen; A. J. Epstein; W. Graupner; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
|
| The X-band spin 1 photoluminescence-detected magnetic resonance of frozen toluene solutions of poly (p-phenylene ethynylene) (PPE) and poly (p- phenylene)-type ladder (LPPP) polymers are presented. The amplitude of the 800- 1100 G wide triplet resonance pattern decreases with decreasing concentration of PPE in toluene and tetrahydrofuran; in frozen saturated solutions of LPPP it is about half of that in neat films. The results suggest the resonance is largely due to ... |
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| Color Variable Bipolar/AC Light-Emitting Devices Based on Conjugated Polymers |
20 SEP 97 |
16 pages |
| Authors:
Y. Z. Wang; D. D. Gebler; D. K. Fu; T. M. Swager; A. J. Epstein; OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS
|
| There is increased interest in developing color variable light emitting devices. We report here the fabrication of color variable bipolar/AC light-emitting devices based on conjugated polymers. The devices consist of blends of pyridine-phenylene and thiophene-phenylene based copolymers sandwiched between the emeraldine base from and the sulfonated form of polyaniline. ITO and Al are used as electrodes. The devices operate under either polarity of driving voltage with different colors of light ... |
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| Organic and Transition Metal Complex Superconductors and Redox Active Conductive Polymers |
07 OCT 96 |
19 pages |
| Authors:
John R. Reynolds; FLORIDA UNIV GAINESVILLE
|
| We have developed and characterized a broad class of synthetic metals and electroactive polymers. Refer to final technical report for AASERT grant F49620-93-1-0322 for an overview of advances made in transition metal complexes as radical anion components in synthetic metals. We have developed a new family of electrochromic polymers utilizing 3,4-ethylenedioxythiophene as an oxidatively polymerizable moiety. These polymers allow Band Gap Engineering such that the full visible spectrum is attained. ... |
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| Living Catalysts for Cyclohexdiene Polymerization |
JUL 96 |
6 pages |
| Authors:
Robert H. Grubbs; CALIFORNIA INST OF TECH PASADENA DIV OF CHEMISTRY AND CHEMICAL ENGINEERING
|
| ROMP polymerization has become an important method for the preparation of polyphenylenevinylenes and polynaphthylenevinylene. The new route allows the band gap and processing properties of the polymers to be varied by the use of side chains and functional groups. These materials are being used to fabricate electroluminescent devices with tunable colors. New techniques have been developed for the synthesis of the starting barrelenes and benzobarrelenes. These synthesis start from the ... |
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| Improved Route to Bridged Planar Poly(p-phenylene) Derivatives for Maximization of Extended pi Conjugation |
07 JUN 95 |
9 pages |
| Authors:
J. S. Lamba; J. M. Tour; SOUTH CAROLINA UNIV COLUMBIA DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| Poly(p-phenylene) (PPP), a highly insoluble polymer that has been studied extensively for its possible electronic and photonic applications, has a 230 twist between the consecutive aryl units due to ortho hydrogen interactions. Attempts to enhance the solubility by substitution of the rings forces the consecutive aryl units even further out of plane resulting in a plummet of the extended conjugation (easily observed by the optical spectra). We recently described a ... |
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| Surface Modification, Organometallic and Polyaryl Coatings, and Flame Spray Technologies for Preventing Corrosion of Metals. |
MAY 1995 |
25 pages |
| Authors:
T. Sugama; BROOKHAVEN NATIONAL LAB UPTON NY
|
| To improve adherent properties of electrogalvanized steel (EGS) to polymeric topcoats, the surfaces of EGS were modified by polyelectrolyte- modified zinc phosphating solution. The electrochemical reaction between phosphating solution and EGS led to the complete coverage with fully grown hopeite crystals after only 5 sec treatment, thereby improving adhesion to topcoating and providing protection of EGS against corrosion. To evaluate the ability of polyphenylene sulfide (PPS) coatings to protect zinc ... |
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| Thermoelectric Properties of Conducting Polymers |
JUL 94 |
41 pages |
| Authors:
Barbara Howell; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD SURVIVABILITY STRUCTU RES AND MATERIALS DIRECTORATE
|
| Development of an inexpensive thermoelectric material which has a better cooling capacity than any currently available would have many practical advantages. On board ships or submarines it would allow a quiet, decentralized cooling architecture, it would reduce usage of chlorofluorocarbons, and would provide less expensive and lighter weight cooling systems. To this end a number of organic materials have been obtained and tested for thermoelectric properties. These include conductive vinyl ... |
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| Interfaces of High-Protection Performance Polyaryls-Coated Zinc Phosphated Steels, Tri-Service Committee on Corrosion Proceedings |
JUN 94 |
13 pages |
| Authors:
Toshifumi Sugama; BROOKHAVEN NATIONAL LAB UPTON NY DEPT OF APPLIED SCIENCE
|
| To evaluate the ability of polyaryl thermoplastic coatings such as Polyphenylenesulfide (PPS) and polyphenyletheretheretherketone (PEEK), to protect zinc phosphate (Zn.Ph)-treated steels from corrosion in a wet, harsh environment (1.0 wt% H2SO4, 3.0 wt% NaCl and 96.0 wt% water at temperature from 25 to 200 deg C), we exposed them in autoclave to measure their performance in heating-cooling cyclic fatigue tests (1 cycle = 12 hr at 200 deg C + ... |
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| Organic Nonlinear Optical (NLO) Polymers. 4. Thermally Stable NLO polymers |
22 MAY 94 |
4 pages |
| Authors:
Michael E. Wright; Edward G. Toplikar; UTAH STATE UNIV LOGAN DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| NLO polymers (NLOPs) based on the poly(p-phenylene) (PPP) backbone were prepared in the study. Starting from readily synthesized NLO-phore/ monomers, homopolymerization afforded low molecular weight PPPs with the NLO- phore attached to the polymer backbone through a sulfone linkage. The thermal and linear optical behavior of the new materials is discussed in the paper. NonLinear Optical, Polymers, Conjugated Polymers, Polyphenylenes |
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| Synthesis of Soluble Halogenated Polyphenylenes. Mechanism for the Coupling Halogenated Lithiobenzenes |
22 NOV 93 |
28 pages |
| Authors:
Eric B. Stephens; Kenneth E. Kinsey; Joanna F. Davis; James M. Tour; SOUTH CAROLINA UNIV COLUMBIA DEPT OF CHEMISTRY AND BIOCHEMISTRY
|
| A method for the synthesis of soluble polyphenylenes that involves the polymerization of 1-halo-4-lithiobenzenes, 1-halo-3-lithiobenzenes, and 1,3- and 1,4-dilithiobenzenes in ethereal solvents is described. The lithiobenzenes are prepared from the corresponding dihalogenated benzenes using tert- butyllithium. By varying the monomers and conditions used, a variety of soluble halogenated polyphenylenes can be obtained with weight average molecular weights (Mw) as high as 6,000 with polydispersities (Mw/Mn) equal to approx. 2.8. The ... |
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| Center for Advanced Electrical and Structural Polymers |
15 OCT 93 |
78 pages |
| Authors:
Frank E. Karasz; MASSACHUSETTS UNIV AMHERST DEPT OF POLYMER SCIENCE AND ENGINEERING
|
| Research in the U.R.I. has been organized into five thrust areas each comprising collateral and coordinated investigations in three departments at UMass and at Wright State University, Foster Miller Inc. and MIT. Electrical properties of pi-conjugated polymers are the focus of one thrust and are defined in terms of their structure-property relationships as well as long term applications. A prototypical polymer has been poly-p-phenylene vinylene. A second thrust has concentrated ... |
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| Ultrastructure Processing of Macromolecular Materials |
25 JUN 93 |
25 pages |
| Authors:
Frank E. Karasz; MASSACHUSETTS UNIV AMHERST DEPT OF POLYMER SCIENCE AND ENGINEERING
|
| The effect of microstructure on miscibility of polymer blends has been investigated in a number of model systems by thermal, mechanical and novel spectroscopic techniques. An understanding of the fundamental basis of the metastable miscibility found in large number of high temperature systems, i.e. these typically involving polyimides or related materials with high Tg's has also been gained. In a complementary investigation we have performed computer simulation studies of the ... |
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| Physical Properties of Injection Molded Liquid Crystal Polymers and High Temperature Engineering Polymers |
MAR 93 |
177 pages |
| Authors:
Nick R . Schott; Robert E. Nunn; Miftahur Rahman; Sudesh Appaji; MASSACHUSETTS UNIV LOWELL DEPT OF PLASTICS ENGINEERING
|
| This experimental study investigated the System Molding of Four Liquid Crystal Polymers, Vectra A 950, Vectra B 950, HX 4000, and Xydar SRT 500 and two High Temperature Engineering polymers, Polyetherimide (Ultem) and Polyphenylene Sulfide (Fortron) and evaluation of mechanical properties, tensile, flexural, and compression of molded samples. |
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| Ultrastructure Processing of Macromolecular Materials |
11 FEB 93 |
23 pages |
| Authors:
Frank E. Karasz; MASSACHUSETTS UNIV AMHERST DEPT OF POLYMER SCIENCE AND ENGINEERING
|
| The research has concurrently involved several areas of investigation in the physical chemistry of macromolecules. A major theme has been the study of the properties of polymer blends. Experimentally we have investigated the effects of microstructure on miscibility in a number of model systems by thermal, mechanical and varied novel spectroscopic techniques, and have also gained a wide understanding of the fundamental basis of the metastable miscibility found in an ... |
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| Enhanced Superconductors |
MAY 92 |
120 pages |
| Authors:
R. B. Olsen; CHRONOS RESEARCH LABS INC SAN DIEGO CA
|
| One of the major challenges facing high temperature superconductors is the making of non-brittle materials. Based on the successful discovery of high temperature perovskite superconductors, a new class of superconducting materials is hypothesized. The proposed class will be mechanically tough and may have high critical temperatures. The proposed material will be inexpensive to manufacture and easily formed into wires and bands. The project's research goal was to detect a superconducting ... |
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| Polymerization of 1-Bromo-4-lithiobenzene in THF. A Route to Soluble Polyphenylenes |
25 APR 92 |
11 pages |
| Authors:
James M. Tour; Eric B. Stephens; Joanna F. Davis; SOUTH CAROLINA UNIV COLUMBIA DEPT OF CHEMISTRY
|
| A synthesis of polyphenylene is described that involves the room temperature polymerization of 1-bromo-4-lithiobenzene in THF. The polymerization was complete within 2 h to afford 65% yield of an ether insoluble fraction of brominated polyphenylene that was soluble in THF, CH2C12 and CHC13. Analysis of the initially formed polymers showed that there was a high bromide content with approximately one bromide for every three aryl rings. Debromination of the material ... |
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| Thermoset Precursor to Monolithic Carbon Glass Prepared by the Pd/Cu- Catalyzed Alkynylation of Polyphenylenes |
25 APR 92 |
8 pages |
| Authors:
Eric B. Stephens; James M. Tour; SOUTH CAROLINA UNIV COLUMBIA DEPT OF CHEMISTRY
|
| The functionalization of (bromophenyl)oligophenylene with several alkynes is described. The bromide groups on the oligomer were replaced with terminal alkynes using a Pd/Cu catalysts system. Substitution of nearly all the original bromide locations was achieved. The functionalized oligomers, freely soluble in THF, exhibited high char yields on thermolysis to 900 deg C under a nitrogen atmosphere. Several of the functionalized oligomers flowed on heating. The oligomer that was functionalized with ... |
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| Environmental Resistance of Amorphous Bonded Thermoplastic Joints, |
APR 1992 |
|
| Authors:
C. Voto; M. Iannone; MIDDLE EAST TECHNICAL UNIV ANKARA (TURKEY)
|
 | Amorphous bonding appears to be a promising method of joining thermoplastic matrix advanced composites. The temperature to bond, lower than for fusion bonding, and the limited dimension of the melted zone, allow significant cost reduction and guarantee good mechanical characteristics. On the other hand a potential problem exists, due to lower resistance to aeronautical solvents and service fluids, because of the amorphous nature of the bonding layers. The basic resistance ... |
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| Molecular Engineering of Liquid Crystalline Polymers |
27 MAR 92 |
218 pages |
| Authors:
Virgil Percec; Dimitris Tomazos; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE
|
| This chapter reviews the molecular engineering of main chain and side chain liquid crystalline polymers. Several factors influencing the phase transitions of liquid crystalline polymers are critically discussed. These include thermodynamics of phase transitions, isomorphism of liquid crystals, rigidity of rod-like mesogens and chemical heterogeneity of main chain liquid crystalline copolymers. The use of polyetherification and copolyetherification and of living cationic polymerization and copolymerization in the manipulation of phase transitions ... |
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| Electronic and Ionic Transport in Processable Conducting Polymers |
28 MAY 91 |
12 pages |
| Authors:
Martin Pomerantz; John R. Reynolds; Krishnan Rajeshwar; Dennis S. Marynick; TEXAS UNIV AT ARLINGTON CENTER FOR ADVANCED POLYMER RESEARCH
|
| Research carried out on this grant includes studies of water soluble polyelectrolyte/polypyrrole composites, conducting polymer/dopant ion interactions, symmetrically and asymmetrically substituted poly(di-2- heterocycle-2,5-disubstitutedphenylenes), poly(5-decylisothianaphthene), polyrrole containing luminescent ions, the use of cyclic voltammetry coupled with UV-vis and Raman spectroscopy, the preparation of polypyrrole films containing nm-sized Platinum particles, the neutral-polaron-bipolaron sequence of oxidation states of polypyrrole in the presence of Oxygen, melt spun fibers of blends of poly(3-dicylthiophene) with polyethylene ... |
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| NMR Studies of Polymeric Solid Electrolytes |
16 MAR 90 |
4 pages |
| Authors:
S. G. Greenbaum; HUNTER COLL NEW YORK
|
| A wide variety of polymer electrolytes containing mobile sodium (+) ions have been studied by sodium 23 NMR. Motional averaging of the NMR linewidth above T(g) and subsequent lifetime broadening about 60K above T(g) was found to be common to all polymer hosts studied, including cross-linked PEO, PPO, MEEP and siloxane-PEO copolymers. Other highlights include the synthesis and study of single ion (cation) conductors, the development of high-pressure NMR capability, ... |
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| Durable Heat Diaphragm from Ordered Polymer Films |
90 |
43 pages |
| Authors:
Anthony P. Lioi; NU-TECH INDUSTRIES INC DAYTON OH
|
| The purpose of this Phase I SBIR study was to investigate the feasibility of using the ordered polymer-p-phenylene benzobisthiazole (PBZT) in high flex life applications. Applications of particular interest include biomedical applications such as the artificial heart or prosthetic heart valves. An accelerated flex life test rig based on a vibration principle was developed that was capable of subjecting film samples to over 3 million flexural cycles per 24 hr ... |
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| Electronic and Ionic Transport in Polymers |
03 OCT 89 |
7 pages |
| Authors:
Martin Pomerantz; John R. Reynolds; Krishnan Rajeshwar; Dennis S. Marynick; TEXAS UNIV AT ARLINGTON DEPT OF CHEMISTRY
|
| By employing Sodium Hydroxide dedoping high/low conductivity interfaces have been prepared. Optoelectrochemical properties of several thiophene-phenylene-thiophene polymers have been studied. Blends of poly(3- decylthiophene) with polyethylene or poly(ethylene terephthalate) have been prepared. The ion binding properties of copolymers of pyrrole and 3-(1-pyrrolyl) propanesulfonate have been studied for the first time using Ru(NH3)6(3+) and Ru(bpy)3(2+) (bpy=2,2'-bipyridyl) as the ion probes. Molecular orbital calculations have been used to estimate the equilibrium ground ... |
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| Properties of Electrochemically Generated Poly(p-Phenylene) |
15 JUL 88 |
39 pages |
| Authors:
Kevin Ashley; Diane B. Parry; Joel M. Harris; Stanley Pons; Douglas N. Bennion; UTAH UNIV SALT LAKE CITY DEPT OF CHEMISTRY
|
| Poly(p-phenylene) (PPP) electrodes formed by anodic oxidation of biphenyl in acetonitrile solutions were examined. As a cell, we observe generally high discharge current densities and rapid discharge rates. PPP electrochemistry and cell performance were found to depend significantly on the nature of the supporting electrolyte present during electrosynthesis and doping. These electrodes were also found to catalyze O2 reduction. Raman and scanning electron microscopic results are presented. Keywords: Conducting polymers, ... |
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| Pyrolysis-Gas Chromatography/Mass Spectrometry of Thermoplastic Polymers |
APR 88 |
|
| Authors:
J. A. Hiltz; M. C. Bissonnette; DEFENCE RESEARCH ESTABLISHMENT ATLANTIC DARTMOUTH (NOVA SCOTIA)
|
| Thermal degradation mechanisms of ten thermoplastic polymers have been investigated using pyrolysis-gas chromatography with mass spectrometric and flame ionization detection. The results indicate that an unknown plastic can be identified on the basis of its degradation products and that interpretation of the degradation product analysis can be used to predict thermal degradation mechanisms and chemical structures of polymers. Identification of thermal degradation products gives in into the hazards involved with ... |
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| Proceedings of the American Society for Composites: Biotechnology Aided Synthesis of Aerospace Composite Resins Held in Dayton, Ohio 25-26 August 1987 |
26 AUG 87 |
|
| Authors:
AMERICAN SOCIETY FOR COMPOSITES DAYTON OH
|
| This report stems form a two-day workshop on Biotechnology Aided Synthesis of Aerospace Composite Resins held August 25th and 26th, 1987 at the Stouffer Dayton Plaza Hotel. This workshop was sponsored by the American Society for Composites with support from the Air Force Office of Scientific Research (AFOSR) and the Air Force Wright Aeronautical Laboratories/Materials Laboratory. This workshop was attended by personnel from government and industry representing both aerospace materials ... |
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| Wittig Synthesis of Conductive Segmented Block Polymer Compositions |
01 AUG 87 |
|
| Authors:
Paul J. Hans; Bernard Gordon III; PENNSYLVANIA STATE UNIV UNIVERSITY PARK PA POLYMER SCIENCE SECTION
|
| Conducting polymers such as polyacetylene and polyparaphenylene have been shown to have electrical conductivities which vary from the insulator to semiconductor and metallic regimes upon doping with electron acceptor or donor molecules. Unfortunately, many of these materials are plagued by undesirable properties such as oxidative instability (in the case of polyacetylene) and intractability or infusibility. Researchers have attempted improvements of the physical properties and environmental stability of polyacetylene by blending ... |
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| Ordered Polymer Nonlinear Optical Materials |
APR 87 |
|
| Authors:
Paul J. Marinaccio; Mark A. Druy; FOSTER-MILLER INC WALTHAM MA
|
| Polyphenylene benzobisthiazole (PBT) has been shown to have a significant third order nonlinear optical effect. Shear orientation, extrusion and quench conditions, post chemical treatments, and post thermal treatments under a variety of conditions all influence the film's nonlinear optical properties. These variables can alter the nonlinear effects since they affect the degree of molecular alignment, the orientation through the film cross section, the degree of crystallinity and the optical quality. ... |
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| Morphology of a Phase Separated and a Molecular Composite 30% PBT/70% ABPBI Block Copolymer |
JAN 87 |
49 pages |
| Authors:
W. W. Adams; Stephen J. Krause; Tim B. Haddock; Gary E. Price; ARIZONA STATE UNIV TEMPE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| The morphology of a triblock copolymer of rigid-rod poly(p-phenylene benzobisthiazole (PBT) and semi-flexible coil poly (2,3(6)benzimidazole) (ABPBI) was examined by wide angle x-ray scattering and scanning and transmission electron microscopy. When samples were vacuum cast from a solution where the amount of 30% PBT/70% ABPBI copolymer was greater than a critical concentration of 5.8%, large-scale phase separation occurred and a film formed containing 0.1- micron particles and platelets in a ... |
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| Nematogenic Block Copolymers of Rigid and Flexible Aromatic Units. I. Synthesis and Characterization |
06 NOV 86 |
|
| Authors:
William R. Krigbaum; Jack Preston; A. Ciferri; Z. Shufan; DUKE UNIV DURHAM NC DEPT OF CHEMISTRY
|
| The phosphorylation reaction of Yamazaki and Higashi was used to prepare wholly aromatic block copolymers containing the rigid units poly(p- benzamide) (PBA) or poly(p-phenylene terephtalamide) (PPD-T) and the flexible units poly(m-phenylene isophthalamide) (MPD-I) or the polyterephthalamide of p- aminobenzhydrazide (PPD-T). Three synthetic procedures were investigated: A) monomers of the flexible block were added to the rigid prepolymer, B) monomers of the flexible block were added to the carboxy terminated rigid ... |
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| Functional Polymers and Sequential Copolymers by Phase Transfer Catalysis. Synthesis of Thermotropic Side-Chain Liquid Crystalline Polymers Containing a Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Main Chain |
01 OCT 86 |
|
| Authors:
Coleen Pugh; V. Percec; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF MACROMOLECULAR SCIENCE
|
| Poly(2,6-dimethyl-1,4-phenylene oxide (PPO) containing pendant mesogenic units separated from the polymer main-chain through spacers of three to ten methylene units were synthesized and characterized. The synthetic pathway used for the chemical modification of PPO involved the radical bromination of its methyl groups followed by phase transfer catalyzed esterification of the resulting bromobenzyl groups with potassium omega-(4-oxybiphenyl)alkanoates and potassium omega-(4-methoxy-4'-oxybiphenyl)-alkanoates. Only the resulting polymers containing ten methylene units as spacer and ... |
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| Physical Techniques for the Study of Sorption, Diffusion, Electrical Properties, and Interfacial Effects in Ordered Polymers: Charge Transport and Conduction Mechanisms in Polymer Fibers |
26 JUL 86 |
|
| Authors:
R. E. Barker Jr.; J. A. Hawk; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE
|
| Electrical conduction in several types of polymer fibers has been investigated under a variety of environmental conditions. The configuration and circumstances of these experiments are quite different from the ordinary types of measurements reported in the literature dealing with the conductivity of thin films. Methods for separating the surface component of the total conductivity from the volume component are developed and experiments are performed on both doped and undoped samples. ... |
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| Characterization of Hybridized Conductive Composites |
25 JUL 86 |
47 pages |
| Authors:
J. J. Reilly; S. J. Thoman; W. W. Lin; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLOGY DIRECTORATE
|
| Injection moldable thermoplastics filled with various hybrid conductive reinforcements have been investigated for their physical/mechanical properties. The thermoplastics studied include polyphenylene sulfide (PPS), polyether etherketone (PEEK) and liquid crystal polymers (LCP's). The reinforcements included various combinations and concentrations of graphite (Gr) fibers, stainless steel (SS) fibers, nickel flakes(NiFlk) and nickel plated graphite (NiGr) fibers. Tensile, flexural, and drop weight impact tests were performed. Fracture morphology of tensile specimens was investigated ... |
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| Study of Transport Properties and Structure of Extended-Chain Polymers: Diffusion and Solubility of Gases |
SEP 85 |
|
| Authors:
R. Edward Barker Jr.; W. S. Huang; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE
|
| The study of the transport properties in extended chain polymers has added to the understanding of relations between their macroscopic and microscopic properties. There was a need to determine the extent to which a new class of high strength extended chain polymers absorb various vapors and how the vapor moves within the materials, which have a highly anisotropic fibrous morphology. The main polymer studied as a representative of the class ... |
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| Study of Transport Properties and Structure of Extended-Chain Polymers |
SEP 85 |
|
| Authors:
R. Edward Barker Jr.; Kenneth R. Lawless; Daniel Y. Chen; VIRGINIA UNIV CHARLOTTESVILLE DEPT OF MATERIALS SCIENCE
|
| The broad objective of the work was to relate charge, heat, and mass transport in the Air Force's extended chain polymers (especially poly-para- phenylene benzobisthiazole PBT) to other electrical, thermal, mechanical nad microstructural properties of the polymers and also to compare these very unusual, highly anisotropic Air Force materials with other materials when it is scientifically relevant or when potential applications may be involved. Special techniques were developed for making ... |
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| Fabrication of Biaxially Oriented Films via Poly(P-phenylene Teraphthalamide)/H2SO4 Liquid Crystalline Dopes |
31 MAY 1984 |
|
| Authors:
J. F. Fellers; J. L. White; TENNESSEE UNIV KNOXVILLE
|
| The fundamental innovation arising from this research is that the state of spatial biaxial order in lyotropic Poly(p-phenylene terephthalamide) (PPTA/H2SO4 liquid crystal solutions is strongly controlled by an externally imposed stress field. Also the orientation only relaxes slowly after the stresses are released. This enables processes to b devised that develop biaxial stress on a flowing liquid crystal to cause high levels of molecular orientation. Since the character of the ... |
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| Development of Lower Cost Trigger Spacer for M577 Fuze |
APR 1984 |
|
| Authors:
J. C. Yoo; T. W. Perkins; HAMILTON TECHNOLOGY INC LANCASTER PA
|
| The objective of this task was to reduce the cost of the trigger spacer assembly by changing material and simplifying fabrication processes. A new material, polyphenylene sulfide, 40% glass reinforced, replaced the current die cast aluminum. The trigger spacer assembly was made using the injection molding process with the spacer pins inserted during the molding process. The secondary and assembly operations required on the aluminum spacer were eliminated. |
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| Characterization of Newly Developed Conductive Composites |
MAR 1984 |
|
| Authors:
L. J. Buckley; I. Shaffer; R. Trabocco; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLOGY DIRECTORATE
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| Conductive composites consisting of various thermoplastics filled with conductive chopped fibers have been studied. The thermoplastics chosen were polyphenylene sulfide (PPS), polyetherimide (PEI), polyamide (Nylon), polycarbonate (PC), and liquid crystalline polyester (LCP). The chopped fibers included graphite (Gr), stainless (SS), aluminum flake (Al Fl), and nickel coated graphite (NiGr). Drop weight impact and tensile properties were determined. Photomicroscopy and scanning electron microscopy were performed on several composites. |
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| Characterization of Newly Developed Conductive Composites |
MAR 84 |
34 pages |
| Authors:
L. J. Buckley; I. Shaffer; R. Trabocco; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLO GY DIRECTORATE
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| Conductive composites consisting of various thermoplastics filled with conductive chopped fibers have been studied. The thermoplastics chosen were polyphenylene sulfide (PPS), polyetherimide (PEI), polyphenylene oxide (PPO), polyamide (Nylon), polycarbonate (PC), and liquid crystalline polyester (LCP). The chopped fibers included graphite (Gr), stainless steel (SS), aluminum flake (Al Fl), and nickel coated graphite (NiGr). Drop weight impact and tensile properties were determined. The effect of fiber loading and type on specific ... |
|
| Characterization of Newly Developed Conductive Composites |
MAR 84 |
34 pages |
| Authors:
L. J. Buckley; I. Shaffer; R. Trabocco; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLO GY DIRECTORATE
|
| Conductive composites consisting of various thermoplastics filled with conductive chopped fibers have been studied. The thermoplastics chosen were polyphenylene sulfide (PPS), polyetherimide (PEI), polyphenylene oxide (PPO), polyamide (Nylon), polycarbonate (PC), and liquid crystalline polyester (LCP). The chopped fibers included graphite (Gr), stainless steel (SS), aluminum flake (Al Fl), and nickel coated graphite (NiGr). Drop weight impact and tensile properties were determined. The effect of fiber loading and type on specific ... |
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| European Scientific Notes. Volume 38. Number 1 |
JAN 1984 |
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| Authors:
L. E. Shaffer; OFFICE OF NAVAL RESEARCH LONDON (ENGLAND)
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| Topics include: Gender-mixed Crews on Dutch Combat Ships; Max-Planck- Institute for Psycholinguistics; Cancer Therapy with Magnetism; 9th European Underwater Biomedical Society Convention; International Center for Genetic Engineering and Biotechnology; Biotechnological Route to Polyphenylene; 2nd Romania-US Seminar on Polymer Chemistry; Statistical Climatology; A Code for Generating Dynamic Models of Robots; Fifth Generation Computing Systems; New Data Logger; Erosion by Liquid and Solid Impact, ELSI VI; Physical Chemistry of the Solid State ... |
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| Ultrastructure Processing of Macromolecular Materials |
SEP 1983 |
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| Authors:
F. E. Karasz; MASSACHUSETTS UNIV AMHERST DEPT OF POLYMER SCIENCE AND ENGINEERING
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| This research has as one of its principal aims the development of electroactive polymers with ultrastructural domains. This research program also incorporates investigations in polymer blends, epoxy plasticization, characterization of rigid rod polymers and other areas. The ultrastructure portion consists of a coordinated research effort with profs. R. Lenz and H. Winter into the synthesis of electrically conducting block copolymers, the structuring of such materials by novel techniques, and the ... |
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| Molecular Level Composite of PBT/ABPBI: Phase Relationships, Processing and Properties |
OCT 1982 |
57 pages |
| Authors:
T. Helminiak; W. -f. Hwang; D. Wiff; C. Benner; G. Price; AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH
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| The concentrated solution phase relationships and bulk polymer morphology of a solvent/rigid rod/flexible coil system were investigated. The solvent was a mixture of two strong acids. The rigid rod polymer was poly-para- phenylene-benzbisthiazole (PBT). The flexible coil polymer was poly-2,5(6) benzimidazole (ABPBI). The concentrated solution and bulk polymer morphologies were investigated by means of polarized optical microscopy, small angle light scattering, scanning electron microscopy, and a wide angle x-ray diffraction ... |
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Reports by Keyword(s)
POLYPHENYLENES
