Materials Science and Engineering Commons^™

Dielectric Properties Of A Ferroelectric Copolymer Langmuir–Blodgett Film, Mahantappa S. Jogad, Stephen Ducharme

Stephen Ducharme Publications

We report measurements of the real (epsilon prime) and imaginary (epsilon double-prime) parts of the relative complex permittivity of a Langmuir–Blodgett film of ferroelectric copolymer of vinylidene fluoride (70%) with trifluoroethylene (30%). The measurements were made in the temperature range of 35 to 125° C, and frequency range of 19 Hz to 5 MHz. The results indicate low frequency loss due to conduction and dielectric loss peak near the ferroelectric–paraelectric phase transition.

Stability And Optimization Of Photoconductivity In Thermally Vacuum Evaporated Indium (Iii) Sulfide Thin Films, Gustavo Rehder, Robert Engelken, Randy Stidham, Richard Tanner, Lee Ketchum, Anil Baral

Journal of the Arkansas Academy of Science

Long term stability of photosensitivity versus time in indium (III) sulfide thin films thermally vacuum evaporated onto photocell-patterned printed circuit boards varies sensitively with several factors including contact metal type, contact metal diffusion and electromigration into the semiconductor, doping, and encapsulation method. Because of the significant photoconductivity and relative low toxicity and environmental impact of this compound semiconductor, it is important to better characterize these dependences toward commercial applications. We will report on measurements of photoconductivity vs. time as functions of such factors and evolving methods to stabilize this photoconductivity.

The Effects Of Incorporation Of Polyethylene Glycol On Properties Of Silica-Carbon Black-Filled Rubber Compound, Yoke Cheng Tang

Student Works (2000-2009)

The use of polyethylene glycol (PEG) to modify the surface of precipitated silica by means of physical adsorption was investigated. The effects of adding PEG on processing, cure and physical properties of a silica-carbon black-filled natural rubber truck tread compound were examined. For each series of investigation, two sets of experiments were conducted. Set I was to check the effects of both physical adsorption due to PEG and chemical modification due to a silane coupling agent, Si-69 on the surface of silica. Set 2 was to check the effects of physical adsorption due to PEG alone on the surface of …

Effect Of Antioxidants On Ultra High Molecular Weight Polyethylene (Uhmwpe), Clifford Schrader

Masters Theses

This thesis presents a study on the effects of antioxidants on the oxidative induction time (OIT), thermal behavior, and hardness property of ultra high molecular weight polyethylene (UHMWPE). The antioxidants were dissolved into methanol alcohol before the solution was mixed with UHMWPE powder. The mixture was degassed under vacuum, and then compression-molded into disks 1.25 in. in diameter.

Different antioxidants were evaluated at concentrations up to 0.6 percent. A 0.6 percent concentration was used to screen the effectiveness of various antioxidants. Effect of antioxidant concentration was investigated in the range between 0 and 0.6 percent. OIT was evaluated on UHMWPE …

Effect Of Temperature On Short-Term Creep Rupture Response In Polymer Matrix Pultruded Composites, Robert Harold Munson

Mechanical & Aerospace Engineering Theses & Dissertations

Polymer matrix pultruded composites have increasingly been used in applications where high strength-to-weight ratio and corrosion resistance are needed. Bridge and pier components are a couple of recent applications due the composite's resistance to corrosion from salt water. In applications of this sort, the material will commonly be subjected to sizable static loads while exposed to varying weather conditions. In using pultruded composites for these applications safely, a better understanding of the material's response to ambient conditions is necessary.

In this thesis, rectangular specimens of a polyester matrix glass reinforced pultruded composite sheet are subjected to both static tensile loading …

The Effects Of Machining On Structure And Tribological Properties Of Ultra High Molecular Weight Polyethylene For Artificial Joint Prostheses, Jinshan Song

Masters Theses

Understanding the effect of machining on the structure and property of subsurface layer of ultra high molecular weight polyethylene (UHMWPE) can significantly facilitate the increase in longevity of artificial joints. This study was performed to investigate the machining effects on the polymeric structure and tribological properties. Machining parameters include cutting speed, tool feed rate and depth of cut. Temperature rise was studied during machining to assess the extent of thermal degradation due to machining. Polymeric structure of the semicrystalline polymer was characterized using differential scanning calorimetry (DSC) in terms of melting enthalpy, crystallinity and melting temperature. Surface texture and hardness …

Mechanical And Tribological Properties Of Composites Of Recycled High Density Polyethylene And Recycled Rubber, Jason G. Boulanger

Masters Theses

This thesis presents a study on the mechanical and tribological properties of composite materials of recycled high density polyethylene (HDPE) and recycled rubber tire particles. The materials were compounded by extrusion and formed into test specimens by injection molding.

The first experiment studied the effect of recycled rubber percentage on mechanical properties of composites of recycled HDPE and recycled rubber. The mechanical properties included tensile strength, percent elongation, hardness, and impact resistance. Recycled rubber concentrations of 0, 5, 10, 15, 20, 25, and 30 percent were tested. The second experiment investigated the tribological properties of recycled HDPE and recycled rubber …

An Experimental Study Of An Advanced Polymeric Material For Use In Total Knee Replacements Including Gait Analysis Of Mobile Knee Bearings, Lisa Ann Scott

Mechanical & Aerospace Engineering Theses & Dissertations

The primary objectives of this research were to clinically examine the New Jersey Low Contact Stress (LCS)™ Rotating Platform and Meniscal knee bearing systems and to investigate the tribological properties of a new polymer for potential application in total joint replacement. Thus, clinical studies were performed on subjects having the LCSTM Rotating Platform knee bearing and subjects having the LCS™ meniscal knee bearing. The results indicated that there was a statistically significant difference in the braking force for both implant groups when compared to a control group. There was also a statistically significant difference noted for the LCS™ Rotating Platform …

Study On Rheological Behavior Of The Composites Of Recycled Hdpe With Recycled Tire Rubber Particles, Yanze Li

Masters Theses

This study was mainly concerned with rheological properties of composites of recycled high density polyethylene (HDPE) with recycled tire rubber particles at shear rates from 1.167 to 116.7 s^-1. The viscosity was investigated in terms of effects of shear rate, shear stress, temperature, concentration of recycled tire rubber particles and heating duration. The temperature was in the range from 160 to 250 °C and the rubber particle concentration was between 0 and 25%. The heat duration for the composites was up to 240 minutes before testing.

The viscosities of composites were decreased with increase in shear rate and …

Effect Of Agricultural Fiber Reinforcement On The Mechanical Properties Of A Recycled Polyethylene Plastic Composite Material, Michael E. Courbat

Dissertations and Theses @ UNI

This study determined the effect of certain agricultural fiber reinforcements on the tensile and impact mechanical properties of a recycled polyethylene plastic composite material. The purpose of the study was to provide information on certain mechanical properties of a recycled polyethylene plastic material as part of a coordinated materials application process.

A prototype product run of the plastic composite material was done and test specimens were selected from this material. Notch impact, tensile, and flexure tests were conducted on test specimens. Test procedures complied with accepted standards from The American Society For Testing and Materials (ASTM). Tests were conducted on …

Sorption Of Chlorinated Organic Compounds By Sedimentary Rocks, Paul M. Mcginley, S. Kesaraju, Ronald D. Gruzesky

KWRRI Research Reports

The sorption of dichlorobenzene and trichlorobenzene on carbonate and shale rocks collected in Kentucky demonstrate that rock organic matter content is a good indicator of sorptive reactivity in rock systems. Although this is similar to soil systems, significant differences between sorption in rock and soil systems exist. Sorption isotherms on these rocks are nonlinear and sorption can be an order of magnitude higher than predicted using correlations from soils and their organic matter content. This sorption reaction could lead to significant concentration tailing during contaminant cleanup. Experimental elution of trichloroethylene from rock filled columns verified that cleanup times might be …

An Investigation Of Recycled High Density Polyethylene Reinforced By Short Glass Fibers, Tony Lynn Alwardt

Masters Theses

The mechanical properties of recycled high density polyethylene (HDPE) reinforced by short glass fibers were investigated. The composites formed by an injection molding process were examined in terms of tensile strength, percent elongation, and hardness. Recycled HDPE was compared to virgin HDPE regarding the effects of fiber concentrations, types, sizes, and treatments. The addition of three coupling agents at different concentrations was investigated.

The virgin HDPE composites slightly outperformed their recycled HDPE counterparts; having higher tensile strength and hardness, but were less ductile. Increase in fiber concentration generally increased the tensile strength and hardness, but the concentration of fibers was …

Fiber Enhanced Viscoelastic Damping Polymers And Their Application To Passive Vibration Control, Houchun Xia

Mechanical & Aerospace Engineering Theses & Dissertations

A new composite damping material is investigated, which consists of a viscoelastic matrix and high elastic modulus fiber inclusions. This fiber enhanced viscoelastic damping polymer is intended to be applied to light-weight flexible structures as surface treatment for passive vibration control. A desirable packing geometry for the composite material is proposed, which is expected to produce maximum shear strain in the viscoelastic damping matrix. Subsequently, a micromechanical model is established in which the effect of fiber segment length and relative motion between neighboring fibers are taken into account. Based on this model, closed form expressions for the effective storage and …

Structural Materials From Recycled High Density Polyethylene And Herbaceous Fibers, And Method For Production, Barton L. Bergquist, Mohammed F. Fahmy

Patents (University of Northern Iowa)

A composite useful for structural components comprised of recycled high density polyethylene and herbaceous fibrous materials and a method to produce composites based on recycled high density polyethylene and chopped herbaceous fibers. An alternative structural composite is disclosed which is comprised of recycled low density polyethylene and chopped herbaceous fibrous material.

Use Of High-Energy Radiation For Degradation Of Environmental Pollutants, Robert D. Guthrie, Manjiri Patwardhan

KWRRI Research Reports

The purpose of this project was to explore the advantages and/or limitations of high-energy radiation treatment as a method for degrading organic pollutants, particularly aryl halides, in an aqueous medium. We have done analyses of ⁶⁰Co-irradiated samples and kinetic studies using pulsed electron beams. For aryl halides containing no more than two fused rings, the main products detected are those of simple halogen replacement by hydrogen, although the amount of aryl halide destroyed was always greater than the total amount of products detected. To accomplish halogen replacement by H, the reaction solvent may not be pure water but must …

Determinations Of Molecular Weight And Molecular Weight Distribution Of High Polymers By The Rheological Properties, Joan Y. Z. Huang

Mechanical & Aerospace Engineering Theses & Dissertations

Several methods are reviewed by which the molecular weight (MW) and molecular weight distribution (MWD) of polymeric material were determined from the rheological properties. A poly (arylene ether) polymer with six different molecular weights was used in this investigation. Experimentally measured MW and MWD were conducted by GPC/LALLS (Gel Permeation Chromatography/Low Angle Laser Light Scattering), and the rheological properties of the melts were measured by a Rheometric System Four rheometer. It was found that qualitative information of the MW and MWD of these polymers could be derived from the viscoelastic properties, with the methods proposed by Zeichner and Pate1, and …

A Dynamic Study Of The Effect Of Cationic Starch Molecular Weight And Charge On Filler And Fines Flocculation, Deflocculation, And Reflocculation, Bob Shian-Hou Ching

Masters Theses

A modified laboratory instrument was used to dynamically monitor the flocculation of fines and filler under various shear conditions on the "seconds" basis. A three-way factorial design and ANOVA were used to evaluate the significance of cationio starch molecular weight and charge in affecting fines and filler flocculation, deflocculation, and reflocculation. The reduction of molecular weight under high shear was suggested by the results. Both main effects and interaction effects of charge and molecular weight were important in determining flocculation. Charge was the only significant factor for the reflocculation process. Molecular weight was more important than charge in imparting shear …

Isolation And Characterization Of The Dimers Formed In The Free-Radical And Anionic Initiated Polymerization Of Alpha-Methylstryene, Kevin S. Bosman

Masters Theses

No abstract provided.

Removing Fluoride From Drinking Water By Organic Polymers, Eleni Davou Achilleos

Civil & Environmental Engineering Theses & Dissertations

Fluoride is a substance that can provide beneficial or detrimental effects depending on the total amount ingested. Naturally occurring high fluoride concentrations exist in many drinking water supplies. The fluoride removal methods developed in the past have been found to be either impractical and/or not cost effective.

The purpose of this study was to determine whether organic polymers can effectively remove fluoride. The water used in this study contained naturally occurring fluoride concentrations between 4.5 to 5.5 mg/1 and it was collected from the City of Franklin, Virginia, water supply system. Laboratory jar test procedures, which simulated a conventional water …

Synthesis And Evaluation Od Ashless Polymeric Lube Oil Addtives Containing Phosphorus, Sulphur And Nitrogen, Salwa Salah Nasr

Archived Theses and Dissertations

No abstract provided.

Wood Finishing For Tree Samples Of Five Honduran Species, Amilcar A. Cruz

Graduate Research Papers

This research report will study the application of four wood finishing techniques to samples of each of five species of Honduran hardwood.

These four wood finishing methods are: The varnish-method, the lacquer method, the antiquing method and the oil-rub method. The researcher will attempt to determine which is the best method for each of the five species.

Analysis Of Moisture Absorption And Diffusion In Fiber Reinforced Polymeric Resin-Matrix Composite Materials, Stephen Stern Tompkins

Mechanical & Aerospace Engineering Theses & Dissertations

The diffusion of moisture through fiber reinforced polymeric-matrix composite materials has been studied analytically. The diffusion in the orthotropic, nonhomogeneous material was modeled, in detail, with a two-dimensional transient diffusion analysis. An effective diffusivity for the composite was determined in terms of the fiber volume fraction and the resin diffusivity. This effective diffusivity is in better agreement with recent data than those previously determined using less complex models.

The influence of both material and environmental parameters on the moisture content of the composite was determined analytically. Predicted moisture contents were compared over a wide range of values for emittance, solar …

Classroom Analysis Of Various Plastics, Paul D. Harrington

Graduate Research Papers

In the junior high plastics course this writer. teaches, the students display more interest in the manipulative activities of the laboratory than in the sit-down classroom activities. The results of this tend to be a once-over-lightly treatment of the technical aspects of plastics and more hands on craft type activities in the laboratory. To bring more balance to the program, an activity needs to be devised which will have more industrial relevance. Such an activity should allow the students a certain amount of freedom and still provide them with technical information and acquaint them with the properties of various plastics. …

Inhibitors And Retarders For The Free Radical Polymerization Of Alpha-Methylstyrene, Alexander Accetta

Masters Theses

No abstract provided.

Electrostatic Fluidized Bed Plastic Powder Coating Process, Richard H. Florer

Graduate Research Papers

The overall objective is the fabrication of a functional electrostatic fluidized bed dry plastic powder coating apparatus which can be utilized in an Industrial Arts laboratory.

Chemistry Of The Oxidant, Ferrate, Its Interaction With Specific Organics Found In Waste Water, Donald H. Williams, J. T. Riley

KWRRI Research Reports

It became obvious during this investigation that while much work has been done with ferrate (VI) chemistry, discrepancies existed in the literature and very little attention had been given possible engineering uses. This work attempted to fulfill these two needs in an exploratory manner.

The preparative techniques were reviewed and mechanical improvements made in one which allowed improved yields. Essentially what was done was to enlarge and improve the filtering technique of the product and use cooler temperatures throughout the preparation. This greatly shortened the time required. Then it was learned that the addition of ethyl alcohol to the final …

Plastic Mounting Technique For Herbaria, Albert Robinson Jr.

Journal of the Arkansas Academy of Science

No abstract provided.