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Measurement techniques for evaluating encapsulant thermophysical properties during cure

Description: Sandia now has the capability to evaluate stresses during cure of epoxies with finite element codes. Numerous material parameters are needed as input to these codes. I present a relatively quick set of tests which enable evaluation of the required thermophysical properties. Ease and accuracy of the tests improve as the reaction rate of the thermoset slows. Material parameters for common encapsulants at Sandia are presented in tables.
Date: June 1, 1996
Creator: Adolf, D.
Partner: UNT Libraries Government Documents Department

MH Test Filler Force Limitations

Description: The OH modules for the DO end calorimeter are being tested by supporting a load to simulate the MH, IH, and EM modules. This test structure, the MH filler, is inserted into the previously assembled OH modules, and then loaded with hydraulic jacks. The maximum test load applied by the jacks is 78,600 lb, which is via the two downstream jacks at 130% of the nominal load. Bill Cooper's memo of 9/10/90 is include as appendix C. This note presents calculations for the AISC maximum allowable stresses/loads of the various parts of the testing assembly. Furthermore, calculations show that the actual test load is less than the AISC allowable.
Date: October 2, 1990
Creator: Primdahl, K. A.
Partner: UNT Libraries Government Documents Department

High Efficiency Steam Turbines with Ultra Long Buckets

Description: The ''High Efficiency Steam Turbines with Ultra Long Buckets'' program developed and analytically validated the conceptual designs for full-speed 54 inch steel-hybrid and 62 inch titanium-hybrid last stage buckets (LSBs). It identified, tested (both environmentally and operationally), and selected candidate lightweight filler materials suitable for steel and titanium LSBs, with extensibility to upstream bucket stages. To mitigate risk and accelerate the introduction of this technology, the project designed and built a full-scale demonstrator 33.5 inch steel-hybrid LSB, with an advanced 3-dimensional aerodynamic shape that may serve as the basis for the first introduction into service. The project included subscale testing of a stage of 33.5 inch buckets in the GE Energy Low Pressure Development Turbine (LPDT) facility. Preliminary investigation into high temperature materials was studied to broaden applicability of this technology. Finally, the program assessed the benefits of hybrid bucket technology including bucket/system dynamic tuning, damping and mid-span damping devices.
Date: December 15, 2005
Creator: Logan, Thomas
Partner: UNT Libraries Government Documents Department

Total System Performance Assessment: Enhanced Design Alternative IV

Description: The purpose of this calculation is to document total system performance assessment modeling of Enhanced Design Alternative (EDA) Feature IV. Total System Performance Assessment (TSPA) calculations for EDA IV are based on the TSPA-VA Base Case which has been modified with a quartz sand invert, quartz sand backfill, line loading and 21 PWR waste packages that have 2-cm thick titanium grade 7 corrosion resistant material (CRM) drip shields that are placed over a 30 cm thick carbon steel (A5 16) waste package with an integral filler material (CRWMS M&O 1999a & 1999b). This document details the changes and assumptions made to the VA reference Performance Assessment Model (CRWMS M&O 1998a) to incorporate the design changes detailed for EDA IV. The performance measure for this evaluation is the expected value dose-rate history at 20 km from the repository boundary.
Date: June 23, 1999
Creator: Mattie, P.D.
Partner: UNT Libraries Government Documents Department

Combined in-situ dilatometer and contact angle studies of interfacial reaction kinetics in brazing.

Description: Multi-component dissimilar material braze joints as shown in Figure 1 consisting of dissimilar base materials, filler materials and wetting agents are of tantamount importance in a wide variely of applications. This work combines dilatometry and contact angle measurements to characterize in-situ the multiple interfacial reaction pathways that occur in such systems. Whereas both of these methods are commonly used tools in metallurgical investigation, their combined use within the context of brazing studies is new and offers considerable additional insight. Applications are discussed to joints made between Beryllium and Monel with TiH{sub 2} as the wetting agent and Cu-28%Ag as the filler material.
Date: January 1, 2001
Creator: Dave, V. R. (Vivek R.); Javernick, D. A. (Daniel A.); Thoma, D. J. (Dan J.); Cola, M. J. (Mark J.); Hollis, K. J. (Kendall J.); Smith, F. M. (Frank M.) et al.
Partner: UNT Libraries Government Documents Department


Description: This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) in response to a request received via a QAP-3-12 Design Input Data Request (Ref. 5.1) from WAST Design (formerly MRSMPC Design). The request is to provide: Specific MPC access requirements for the addition of filler materials at the MGDS (i.e., location and size of access required). The objective of this analysis is to provide a response to the foregoing request. The purpose of this analysis is to provide a documented record of the basis for the response. The response is stated in Section 8 herein. The response is based upon requirements from an MGDS perspective.
Date: September 3, 1996
Creator: Wallin, W.
Partner: UNT Libraries Government Documents Department

Modified epoxy coatings on mild steel: A study of tribology and surface energy.

Description: A commercial epoxy was modified by adding fluorinated poly (aryl ether ketone) and in turn metal micro powders (Ni, Al, Zn, and Ag) and coated on mild steel. Two curing agents were used; triethylenetetramine (curing temperatures: 30 oC and 70 oC) and hexamethylenediamine (curing temperature: 80 oC). Variation in tribological properties (dynamic friction and wear) and surface energies with varying metal powders and curing agents was evaluated. When cured at 30 oC, friction and wear decreased significantly due to phase separation reaction being favored but increased when cured at 70 oC and 80 oC due to cross linking reaction being favored. There was a significant decrease in surface energies with the addition of modifiers.
Date: August 2009
Creator: Dutta, Madhuri
Partner: UNT Libraries

Desorption Kinetics of H2O, H2, CO, and CO2 from Silica Reinforced Polysiloxane

Description: We performed temperature programmed desorption up to 500K on silica-reinforced polysiloxane in both solid and foamed forms (M9787 and M9750 respectively). Our data show that H{sub 2}O was the dominant desorbing species in both forms of silicone (on the order of 100 {micro}g of physisorbed water and 900 {micro}g of chemisorbed water per gram of polymer), which are expected to be very hydrophilic when dehydrated. Detailed studies of the TPD spectra of H{sub 2}O from the silicones and from the fumed silica fillers suggest that H{sub 2}O molecules preferentially adsorbed on the surface of silica particles contained in the silicones with activation energies of desorption of 15 {+-} 3 kcal/mol and 50 {+-} 10 kcal/mol. There was strong evidence of H{sub 2} desorption below 400K from the silicones. The equivalent concentration of H{sub 2} in the silicones was 0.44 {micro}g of H{sub 2} per gram of silicone. Other species desorbing from the silicones were CO, and CO{sub 2} with concentrations on the order of 2.5 {micro}g, and 1.6 {micro}g per gram of silicone and activation energies of desorption of 10 {+-} 2 kcal/mol and 9.5 {+-} 1.5 kcal/mol, respectively.
Date: August 11, 1999
Creator: Dinh, L. & Balooch, M.
Partner: UNT Libraries Government Documents Department

The in-situ generation of silica reinforcement in modified polydimethylsiloxane elastomers

Description: Structure and properties of a series of modified polydimethylsiloxane (PDMS) elastomers reinforced by {ital in situ} generated silic particles were investigated. The PDMS elastomer was modified by systematically varying the molecular weight between reactive groups incorporated into the backbone. Tetraethoxysilane (TEOS) and partial hydrolyzate of TEOS were used to generate silic particles. Chemistry and phase structure of the materials were investigated by {sup 29}Si magic angle spinning nuclear magnetic resonance spectroscopy and swelling experiments.
Date: June 1, 1996
Creator: Prabakar, S; Bates, S.E.; Black, E.P. & Ulibarri, T.A.
Partner: UNT Libraries Government Documents Department

Aerosol-Assisted Self-Assembly of Mesostructured Spherical Nanoparticles

Description: Nanostructured particles exhibiting well-defined pore sizes and pore connectivities (1-, 2-, or 3-dimensional) are of interest for catalysis, chromatography, controlled release, low dielectric constant fillers, and custom-designed pigments and optical hosts. During the last several years considerable progress has been made on controlling the macroscopic forms of mesoporous silicas prepared by surfactant and block copolymer liquid crystalline templating procedures. Typically interfacial phenomena are used to control the macroscopic form (particles, fibers, or films), while self-assembly of amphiphilic surfactants or polymers is used to control the mesostructure. To date, although a variety of spherical or nearly-spherical particles have been prepared, their extent of order is limited as is the range of attainable mesostructures. They report a rapid, aerosol process that results in solid, completely ordered spherical particles with stable hexagonal, cubic, or vesicular mesostructures. The process relies on evaporation-induced interfacial self-assembly (EISA) confined to a spherical aerosol droplet. The process is simple and generalizable to a variety of materials combinations. Additionally, it can be modified to provide the first aerosol route to the formation of ordered mesostructured films.
Date: March 23, 1999
Creator: Brinker, C.J.; Fan,; H.; Lu, Y.; Rieker, T.; Stump, A. et al.
Partner: UNT Libraries Government Documents Department

Effective thermal conductivity of a thin composite material

Description: The thermal conductivity of a randomly oriented composite material is modeled using a probabilistic approach in order to determine if a size effect exists for the thermal conductivity at small composite thickness. The numerical scheme employs a random number generator to position the filler elements, which have a relatively high thermal conductivity, within a matrix having a relatively low thermal conductivity. Results indicate that, below some threshold thickness, the composite thermal conductivity increases with decreasing thickness, while above the threshold the thermal conductivity is independent of thickness. The threshold thickness increases for increasing filler fraction and increasing k{sub f}/k{sub m}, the ratio between filler and matrix thermal conductivities.
Date: December 1996
Creator: Phelan, P. E. & Niemann, R. C.
Partner: UNT Libraries Government Documents Department

Fabrication and evaluation of uniform and gradient density epoxies

Description: Filled epoxy materials which vary in density in a designed manner have been fabricated and their mechanical properties evaluated. Density variations were produced by incorporating different volume fractions of either glass microballoons (GMB) or alumina. Several different sample types were evaluated including uniform density (0.8 g/cm{sup 3} < {rho} < 2.0 g/cm{sup 3}) samples and gradient density samples (GMB only, 0.8 g/cm{sup 3} < {rho} < 1.2 g/cm{sup 3}). The uniform density specimens were evaluated for the effects of filler type and concentration on modulus and toughness. Results indicated that addition of alumina filler significantly increased the resulting modulus while addition of GMB had little measurable effect. These differences could be understood in terms of the differing moduli of the additives relative to that of the epoxy matrix. In the former case the alumina particulates had a modulus much greater than that of the epoxy while in the latter case, the modulus of the GMB additive was only slightly greater than that of the matrix. Addition of either filler significantly degraded the toughness of the composite specimens and precluded the use of gradients to enhance toughness performance. Discontinuous {open_quotes}block{close_quotes} gradients used for testing were fabricated by simple sequential pours of formulations with different GMB loadings and were evaluated for modulus, strength and ductility. Continuous gradients were fabricated in process studies by programmed shifts in the peristaltic pumping/mixing ratio of epoxies filled with either alumina or GMB. None of the continuous gradient materials were mechanically tested. These results suggest that applications utilizing gradient materials containing alumina and similar high modulus fillers to provide designed stiffness rather than improved toughness are the most appropriate targets for future investigation.
Date: November 1, 1997
Creator: Domeier, L.A.; Skala, D.M. & Goods, S.H.
Partner: UNT Libraries Government Documents Department

A new and superior ultrafine cementitious grout

Description: Sealing fractures in nuclear waste repositories concerns all programs investigating deep burial as a means of disposal. Because the most likely mechanism for contaminant migration is by dissolution and movement through groundwater, sealing programs are seeking low-viscosity sealants that are chemically, mineralogically, and physically compatible with the host rock. This paper presents the results of collaborative work directed by Sandia National Laboratories (SNL) and supported by Whiteshell Laboratories, operated by Atomic Energy of Canada, Ltd. The work was undertaken in support of the Waste Isolation Pilot Plant (WIPP), an underground nuclear waste repository located in a salt formation east of Carlsbad, NM. This effort addresses the technology associated with long-term isolation of nuclear waste in a natural salt medium. The work presented is part of the WIPP plugging and sealing program, specifically the development and optimization of an ultrafine cementitious grout that can be injected to lower excessive, strain-induced hydraulic conductivity in the fractured rock termed the Disturbed Rock Zone (DRZ) surrounding underground excavations. Innovative equipment and procedures employed in the laboratory produced a usable cement-based grout; 90% of the particles were smaller than 8 microns and the average particle size was 4 microns. The process involved simultaneous wet pulverization and mixing. The grout was used for a successful in situ test underground at the WIPP. Injection of grout sealed microfractures as small as 6 microns (and in one rare instance, 3 microns) and lowered the gas transmissivity of the DRZ by up to three orders of magnitude. Following the WIPP test, additional work produced an improved version of the grout containing particles 90% smaller than 5 microns and averaging 2 microns. This grout will be produced in dry form, ready for the mixer.
Date: April 1, 1997
Creator: Ahrens, E.H.
Partner: UNT Libraries Government Documents Department

Fillers and potting compounds. Quarterly report, October--December, 1971

Description: The work this period concentrated on packaging RTV silicone fluids in a commercial purchased package-bag. The samples will be stored for a period of six months at ambient temperature. Because of the rigid film of the Bipax Bag, it is doubtful that this method of packaging silicones will develop into an acceptable process. To enhance this process, a more pliable bag should be incorporated into the packaging system.
Date: December 31, 1972
Creator: Montague, J.L.
Partner: UNT Libraries Government Documents Department

Work of Adhesion Measurements of Silicone Networks Using Contract Mechanics

Description: Work of adhesion (Wa) measurements are being studied for several types of polymer/metal combinations in order to obtain a better understanding of the adhesive failure mechanisms for systems containing encapsulated and bonded components. A primary concern is whether studies of model systems can be extended to systems of technological interest. One study performed in our laboratory involved the determination of Wa between silicone (PDMS) and Al surfaces in order to establish potential adhesive failure mechanisms. Our initial work with PDMS was based on Dow Corning 170 Sylgard. PDMS hemispheres were synthesized following the procedure outlined by Chaudhury and Whitesides where the filler was stripped from the commercial silicone by centrifuging. Wa between PDMS surfaces was determined using the JKR method. Our results for the Wa of PDMS were in agreement with those reported by Chaudhury and Whitesides. However, further JKR studies using these PDMS hemispheres on flat Al surfaces were fraught with difficulty. We could not discriminate hydrogen-bonding effects between Al{sub 2}O{sub 3} and hydroxyl groups in the PDMS and other possible bonding mechanisms. It was suggested that commercial systems contain inhibitors and additives that interfere with understanding the PMDS/Al interface. Therefore, the current study uses pure PDMS networks synthesized in our lab. Also, two contact mechanics methods were deployed to measure the Wa--JKR method using two hemispheres and a LEFM method using a cylinder containing a circumferential crack. This paper contains a description of the synthesis of the PDMS used for these studies and the determination of Wa between PDMS surfaces using the JKR method, contact angle measurements, and a LEFM method that consists of a cylinder containing a circumferential crack.
Date: April 21, 1999
Creator: Benkoski, J.; Emerson, J.A.; Miller, G.V. & Pearson, R.A.
Partner: UNT Libraries Government Documents Department

Thermal stability of LX-09 chemical reactivity testing. Final report

Description: Several CRT tests were performed with LX-09 using sample containers obtained from LLL. These containers were used to help eliminate differences that were inherent in the design of the various sample containers used by the different laboratories. Initial experiments showed poor agreement in test data between LLL and Pantex containers until Pantex containers were fitted with different valves. Later experiments show no significant differences in test data between the two types of containers after the modification. Fillers of stainless steel (used in LLL containers) and of glass (used in Pantex containers) were interchanged with-out significant differences in results. Results of tests with PBX 9404 and with LX-04-1 are included.
Date: September 1, 1971
Creator: Teter, A.C.
Partner: UNT Libraries Government Documents Department

Crystallization Behavior of M97 Series Silicone Cushions

Description: M97 series siloxanes are poly(dimethyl-diphenyl) siloxanes that are reinforced through a mixture of precipitated and fumed silica fillers which are blended in through the addition of a short chain polydimethylsiloxane processing aid. M97 silicones exhibit crystallization at -80.25 C by thermal (modulated differential scanning calorimetry) and mechanical (dynamic mechanical analysis) techniques. Isothermal dynamic mechanical analysis experiments illustrated that crystallization occurred over a 1.8 hour period in silica-filled systems and 2.8 hours in unfilled systems. The onset of crystallization typically occurred after a 30 minute incubation/nucleation period. {gamma}-radiation caused the crystallization rate to decrease proportionally with dosage, but did not decrease the amount of crystallization that ultimately occurred. Irradiation in vacuum resulted in slower overall crystallization rates compared to air irradiation due to increased crosslinking of the polymer matrix under vacuum. Modulated differential scanning calorimetry contrasted the crystallization and melting behavior of pure PDMS versus the M97 base polymer and helped determine which component of the composite was the origin of the crystallization phenomena.
Date: September 7, 2000
Creator: Chien, A.; DeTeresa, S.; Cohenour, R.; Schnieder, J.; LeMay, J. & Balazs, B.
Partner: UNT Libraries Government Documents Department

Formulation of Molding Materials From Recycled Printed Wiring Boards

Description: The objective of this project was to formulate the pulverized electronic waste (PEW) stream derived from grinding obsolete electronic assemblies and combine this material with thermoplastic or thermosetting polymers into useful, high-value commercial products materials. PEW consists primarily of various thermoset plastic materials and glass fibers from the printed wiring boards, along with ceramic pieces from chip carriers and other electronic components. Typically, the thermosetting materials have the same desirable properties as in the original electronic assembly, including relatively high temperature resistance, excellent chemical resistance, and flame retardancy. These properties combine to make PEW an inherently good inert filler material for plastic composites.
Date: April 20, 1998
Creator: Lula, J.W. & Bohnert, G.W.
Partner: UNT Libraries Government Documents Department


Description: The results of laboratory investigations and supporting technical assessments conducted under DOE Subcontract No. DE-FG26-03NT41795 are reported for the period September 1, 2003 to August 31, 2004. This contract is with the University of Kentucky Research Foundation, which supports work with the University of Kentucky Center for Applied Energy Research and The Pennsylvania State University Energy Institute. The worked described was part of a project entitled ''Advanced Gasification By-Product Utilization''. This work involves the development of technologies for the separation and characterization of coal gasification slags from operating gasification units, activation of these materials to increase mercury and nitrogen oxide capture efficiency, assessment of these materials as sorbents for mercury and nitrogen oxides, and characterization of these materials for use as polymer fillers.
Date: April 1, 2005
Creator: Andrews, Rodney; Rubel, Aurora; Groppo, Jack; Geertsema, Ari; Maroto-Valer, M. Mercedes; Lu, Zhe et al.
Partner: UNT Libraries Government Documents Department

Aging Studies of VCE Dismantlement Returns

Description: VCE is an ethylene/vinyl acetate/vinyl alcohol terpolymer binder for filled elastomers which is designed to accept high filler loadings. Filled elastomer parts consist of the binder (VCE), a curing agent (Hylene MP, diphenol-4-4{prime}-methylenebis(phenylcarbamate)), a processing aid (LS, lithium stearate), and filler particles (typically 70% fraction by weight). The curing of the filled elastomer parts occurs from the heat-activated reaction between the hydroxyl groups of VCE with the Hylene MP curing agent, resulting in a cross-linked network. The final vinyl acetate content is typically between 34.9 and 37.9%, while the vinyl alcohol content is typically between 1.27 and 1.78%. Surveillance data for this material is both scarce and scattered, complicating the assessment of any aging trends in systems. In addition, most of the initial surveillance efforts focused on mechanical properties such as hardness and tensile strength, and chemical information is therefore lacking. Material characterization and aging studies had been performed on previous formulations of the VCE material but the Ethylene Vinyl Acetate (EVA) starting copolymer is no longer commercially available. New formulations with replacement EVA materials are currently being established and will require characterization as well as updated aging models.
Date: October 17, 2011
Creator: Letant, S; Alviso, C; Pearson, M; Albo, R; Small, W; Wilson, T et al.
Partner: UNT Libraries Government Documents Department

Fibrous Fillers to Manufacture Ultra High Ash/Performance Paper

Description: The paper industry is one of the largest users of energy and emitters of CO2 in the US manufacturing industry. In addition to that, it is facing tremendous financial pressure due to lower cost imports. The fine paper industry has shrunk from 15 million tons per year production to 10 million tons per year in the last 5 years. This has resulted in mill closures and job loses. The AF&amp;PA and the DOE formed a program called Agenda 2020 to help in funding to develop breakthrough technologies to provide help in meeting these challenges. The objectives of this project were to optimize and scale-up Fibrous Fillers technology, ready for commercial deployment and to develop ultra high ash/high performance paper using Fibrous Fillers. The goal was to reduce energy consumption, carbon footprint, and cost of manufacturing paper and related industries. GRI International (GRI) has been able to demonstrate the techno - economic feasibility and economic advantages of using its various products in both handsheets as well as in commercial paper mills. GRI has also been able to develop sophisticated models that demonstrate the effect of combinations of GRI's fillers at multiple filler levels. GRI has also been able to develop, optimize, and successfully scale-up new products for use in commercial paper mills.
Date: April 30, 2009
Creator: Mathur, Dr. VIjay K.
Partner: UNT Libraries Government Documents Department


Description: Nanoscale montomorillonite (MMT) clay fillers became dispersed in a polyphenylenesulfied (PPS) matrix through the processes of octadecylamine (ODA) intercalation {yields} molten PPS co-intercalation {yields} exfoliation. Cooling this molten exfoliated material led to the formation of a PPS/MMT nanocomposite. The MMT nanofiller conferred three advanced properties on the semi-crystalline PPS: First, it raised its melting point by nearly 40 C to 290 C; second, it increased its crystallization energy, implying that an excellent adherence of the nanofillers surfaces to PPS in terms of a good interfacial bond; and, third, it abated the degree of its hydrothermal oxidation due to sulfide {yields} sulfite linkage transformations. When this advanced PPS nanocomposite was used as a corrosion-preventing coating for carbon steel in a simulated geothermal environment at 300 C, a coating of {approx}150 {micro}m thickness adequately protected the steel against hot brine-caused corrosion. In contrast, an MMT-free PPS coating of similar thickness was not nearly as effective in mitigating corrosion as was the nanocompsite; in fact, the uptake of corrosive ionic electrolyte by the unmodified coating increased with an extending exposure time.
Date: June 1, 2006
Creator: SUGAMA, T. & GAWLIK, K.
Partner: UNT Libraries Government Documents Department