NASA Scientific and Technical Aerospace Reports

20040111196 Institute of Industrial Technology TNO, Eindhoven, Netherlands
Properties and Performance of Surface Tolerant Coatings, Phase 2, Repaintability
Tiemens, H. J.; December 15, 2003; 35 pp.; In Dutch
Contract(s)/Grant(s): A02/KM/129; TNO Proj. 007.62147
Report No.(s): TD-2003-0232-Phase 2; Rept-42/03.009451/sec-Phase-2; Copyright; Avail: Other Sources
The repaintability of paint systems based on surface tolerant epoxies has been tested. Painted test panels have been
subjected to a modified water immersion test and a salt fog test. Repaintability of systems with a polyurethane (PU) top coat
is good. Adhesion of the tested one pack product is somewhat lower than the adhesion of the two-pack products. Repainting
a system with an alkyd top coat with PU produces poor adhesion which, surprisingly, is somewhat better than for the original
alkyd. Of the two surface tolerant epoxies, epoxy-B scores better on some points than epoxy-A, but the differences are limited.
The tested one-pack PU is more sensitive to blistering in the water immersion test, but eliminates the normal sensitivity to
cathodic disbonding of the tested epoxy primers. Sanding the surfaces before repainting made no difference for the
performance after repainting. A complete anticorrosion paint system could be applied over (artificially) aged epoxy primer,
resulting in good adhesion, also without sanding.
Author
Paints; Primers (Coatings); Corrosion Resistance; Environmental Tests; Water Immersion
20040111224 NASA Glenn Research Center, Cleveland, OH, USA
Inter and Intra Molecular Phase Separation Environment Effects on PI-PEO Block Copolymers for Batteries and Fuel
Cells
Xue, Chen-Chen; Meador, Mary Ann B.; Eby, R. K.; Cheng, Stephen Z. D.; Ge, Jason J.; Cubon, Valerie A.; [2002]; 2 pp.;
In English; 11th International Meeting on Lithium Batteries, 23-28 Jun. 2002
Contract(s)/Grant(s): 22-708-31-13; Copyright; Avail: CASI; A01, Hardcopy
Rod-coil molecules have been introduced as a novel type of block copolymers with unique microstructure due to their
ability to self-assemble to various ordered morphologies on a nanometer length scale. These molecules, comprised two homo
polymers joined together at one end, microphase separate into ordered, periodic arrays of spheres, cylinders in the bulk state
and or solution. To get ordered structure in a reasonable scale, additional force field are applied, such as mechanical shearing,
electric field and magnetic field. Recently, progress has made it a possible to develop a new class of polyimides
(PI)-Polyethylene oxide (PEO) that are soluble in polar organic solvents. The solvent-soluble PI-PEO has a wide variety of
applications in microelectronics, since these PI-PEO films exhibit a high degree of thermal and chemical stability. In this
paper, we report the self-assembled ordered structure of PI-PEO molecules formed from concentrate solution.
Derived from text
Block Copolymers; Fuel Cells; Rods; Electric Batteries; Phase Separation (Materials); Polyethylenes; Oxides; Coils
20040111277 Building and Construction Research TNO, Delft, Netherlands
Theoretical and Experimental Investigation into the Static and Dynamic Properties of Foam Rubber Pads and Rubber
Tiles
Korse, T. H.; April 15, 2004; 30 pp.; In English
Contract(s)/Grant(s): A03/KM/113; TNO Proj. 006.38142
Report No.(s): TD-2004-0109; Rept-2004-CMC-R034; Copyright; Avail: Other Sources
The shock loading of a naval vessel, due to an underwater explosion, may be reduced considerably by covering the outer
side of the hull of the vessel with a layer of compressible gas filled material. For this purpose, a foam rubber pad or a rubber
tile may be applied. The load-deflection curve of the used material gives information about its compressibility. The
investigation shows that the static load-deflection characteristic of the foam rubber pad corresponds with the load-deflection
characteristic according to the theoretical gas model of the foam rubber pad. The static load-deflection characteristic of the
rubber tile is mainly determined by the mechanical properties of the rubber ribs of the tile. The rubber tile shows a
considerably higher stiffness than the foam material. The dynamic load-deflection characteristic of the foam rubber pad and
the rubber tile are about equal to the corresponding static load-deflection characteristic. During dynamic loading, both
materials show damping.
Author
Damping; Foams; Hulls (Structures); Rubber; Dynamic Loads; Load Distribution (Forces)
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