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Effectiveness of Flame Retardants in TufFoam

Abelow, Alexis E.; Nissen, April E.; Massey, Lee T.; Whinnery, LeRoy L.

An investigation of polyurethane foam filled with known flame retardant fillers including hydroxides, melamine, phosphate-containing compounds, and melamine phosphates was carried out to produce a low-cost material with high flame retardant efficiency. The impact of flame retardant fillers on the physical properties such a s composite foam density, glass transition temperature, storage modulus, and thermal expansion of composite foams was investigated with the goal of synthesizing a robust rigid foam with excellent flame retardant properties.

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Imaging indicator for ESD safety testing

Whinnery, LeRoy L.; Nissen, April E.

This report describes the development of a new detection method for electrostatic discharge (ESD) testing of explosives, using a single-lens reflex (SLR) digital camera and a 200-mm macro lens. This method has demonstrated several distinct advantages to other current ESD detection methods, including the creation of a permanent record, an enlarged image for real-time viewing as well as extended periods of review, and ability to combine with most other Go/No-Go sensors. This report includes details of the method, including camera settings and position, and results with wellcharacterized explosives PETN and RDX, and two ESD-sensitive aluminum powders.

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Thermomechanical characterization of thermoset urethane shape-memory polymer foams

Journal of Applied Polymer Science

Domeier, Linda A.; Nissen, April; Goods, Steven H.; Whinnery, LeRoy L.; McElhanon, James

The shape-memory polymer performance of urethane foams compressed under a variety of conditions was characterized. The foams were water-blown thermosets with a closed-cell structure and ranged in density from about 0.25 to 0.75 g/cm3. Compressive deformations were carried out over a range of strain levels, temperatures, and lateral constraints. Recovery stresses measured between fixed platens were as high as 4 MPa. Recovery strains, measured against loads up to 0.13 MPa, demonstrated the effects of various parameters. The results suggest that compression near the foam glass-transition temperature provided optimal performance. Foams with densities of about 0.5 g/cc and compressed 50% provided a useful balance (time, strain, and load) in the recovery performance. © 2009 Wiley Periodicals, Inc.

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TufFoam™: A TDI-free water-blown polyurethane foam

International SAMPE Technical Conference

Whinnery, LeRoy L.; Goods, Steven H.; Keifer, Patrick N.

TufFoam™ is a TDI-free, water-blown, closed-cell, rigid polyurethane foam (PU) initially formulated as an electronics encapsulant to mitigate the effects of harsh mechanical environments. Because it contains no TDI, the handling hazards and chemical sensitization associated with exposure during processing of common, commercial PU foams are obviated. The mechanical properties of TufFoam™ have been found to be comparable or superior to conventional TDI-based foams. Beyond its original intent, it has since found use in a variety of additional applications, including as a structural material and as a thermal and electrical insulating material. TufFoam™ constituents are commercially available in commodity quantities and batch processing schedules have been developed for its preparation at densities ranging from 0.03 to 0.70 g/cc (2 to 40 pcf). TufFoam™ has a uniform, fine cell structure over the entire range of density explored. Its Tg is somewhat dependant on the cure temperature, but is approximately 127°C when cured at 65°C. The coefficient of thermal expansion (CTE) is 7x10 -5 °C -1. TufFoam™ is electrically insulating with a volume resistivity of 3x10 17 ohm-cm at a density of 0.1 g/cc.

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Protection of alodine coatings from thermal aging by removable polymer coatings

Bradshaw, Robert W.; Wagstaff, Brett W.; Whinnery, LeRoy L.

Removable polymer coatings were evaluated as a means to suppress dehydration of Alodine chromate conversion coatings during thermal aging and thereby retain the corrosion protection afforded by Alodine. Two types of polymer coatings were applied to Alodine-treated panels of aluminum alloys 7075-T73 and 6061-T6 that were subsequently aged for 15 to 50 hours at temperatures between 135 F to 200 F. The corrosion resistance of the thermally aged panels was evaluated, after stripping the polymer coatings, by exposure to a standard salt-fog corrosion test and the extent of pitting of the polymer-coated and untreated panels compared. Removable polymer coatings mitigated the loss of corrosion resistance due to thermal aging experienced by the untreated alloys. An epoxide coating was more effective than a fluorosilicone coating as a dehydration barrier.

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33 Results
33 Results