Keeping Cool in Extreme HeatA new foam knows how to keep its cooleven under extreme high temperatures.NASA's Langley Research Center neededa lightweight foam that could retain itsstructural integrity under temperaturesranging from -423 to +482 °F, for itssecond-generation Reusable LaunchVehicles (RLV).Langley's RLV airframe design requirednew insulation material for the fuel tanks,which are exposed to extreme temperaturechanges over a matter of seconds.Through a partnership with Unitika Ltd.,NASA's Langley Research Center createda foam based on high temperature resistantpolyimide chemistry. The patented foam,named TEEK, is non-exclusively licensedto SORDAL, Inc., of Holland, Michigan.The new low-density foam can be processedinto forms or used to fill structures suchas honeycomb. Also unique is its abilityto foam in place during installation andrepair operations. Most foam must be cutto fit a certain area, and then insertedand molded. This process takes time, andusually a great deal of the product iswasted in the attempt to fit the foam.The new foam is directly applied to theinstallation or repair site, eliminatingthe excess foam that is typically cut awayand discarded.TEEK offers superior insulation and supportqualities, but its greatest advantage isits heat and flame resistance abilities.The TEEK polyimide foam met all of NASA'sneeds and also managed to drasticallyreduce the weight of the RLV.~ Full Article @NASA STI SpinoffRead more…
Polyimide-Foam/Aerogel Compositesfor Thermal InsulationComposites of specific types of polymerfoams and aerogel particles or blanketshave been proposed to obtain thermalinsulation performance superior to thoseof the neat polyimide foams.These composites have potential to alsoprovide enhanced properties for vibrationdampening or acoustic attenuation.The specific type of polymer foam isdenoted "TEEK-H," signifying a series,denoted "H," within a family of polyimidefoams that were developed at NASA'sLangley Research Center and arecollectively denoted "TEEK" (an acronymof the inventors' names).The specific types of aerogels includeNanogel® aerogel particles from CabotCorporation in Billerica, MA. and ofSpaceloft® aerogel blanket from AspenAerogels in Northborough, MA.The composites are inherently flame-retardantand exceptionally thermally stable.Because of thermal cycling, aging, andweathering most polymer foams do not performwell at cryogenic temperatures and willundergo further cracking over time.The TEEK polyimides are among the fewexceptions to this pattern, and the proposedcomposites are intended to have all thedesirable properties of TEEK-H foams, plusimproved thermal performance along withenhanced vibration or acoustic-attenuationperformance.A composite panel as proposed would befabricated by adding an appropriate amountof TEEK friable balloons into a mold toform a bottom layer. A piece of flexibleaerogel blanket material, cut to the desiredsize and shape, would then be placed onthe bottom TEEK layer and sandwichedbetween another top layer of polyimide friableballoons so that the aerogel blanket wouldbecome completely encased in an outer layerof TEEK friable balloons. Optionally, theprocess could be further repeated to producemultiple aerogel-blanket layers interspersedwith and encased by TEEK friable balloons.The sandwiching of aerogel bulk-fill particleswould follow the same methodology or couldbe mixed directly with friable balloons upto 40% weight loading of the aerogel particlesto friable balloons. After sandwiching ormixing of the polymide and aerogel components,the mold, without a top cover, would beplaced in a convection furnace and heated ata temperature of 250 °C for one hour.Then the top cover would be placed on the moldand the temperature increased to about 320 °Cfor between 1 and 3 hours for full imidizationof the polyimide component.The resulting composite should have all thedesirable properties of TEEK, and its effectivethermal conductivity should be less than thatof an approximately equally dense panel madeof TEEK foam only. The heat transfer reductionis directly proportional to % loading of theaerogel component. The excellent structuralintegrity of the foam material is maintainedin the composite formulations.~ Full Article @Nasa Tech BriefsRead more…
RP46 PERFORMANCEWith a continuous operating temperature rangefrom -150ºF to +675ºF and the ability towithstand super-hot spikes up to +1,500ºF,RP46 is ideal for many aerospace applicationsrequiring BOTH weight reduction AND highperformance.RP46 exhibits high mechanical strength andstructural durability at elevated temperatures.It also features significantly less moistureabsorption and is therefore less susceptibleto moisture induced damage.RP46 demonstrates excellent thermal oxidativestability and resistance to microcracking.AvailabilityDesigned as a superior alternative to existingpolyimides, RP46 is available as a liquid forprepreg of carbon, glass or quartz fabric; oras a powder for compression molding hightemperature bearings, slip rings or races.RP46 Polyimide Homepage"Kilogram for kilogram, RP46 is stronger thanaluminum, steel or even titanium."~ from :Thermoset Resinsby K. L. Forsdykeand T. F. StarrPreview@GoogleBooksRead more…
Clevios(TM) PH1000 MaterialBreaks Conductivity RecordIt is recognized that the transparent conductorPEDOT:PSS polymer is a key component for theemerging technology of printed electronics.This technology will lead to novel devices suchas printed displays, printed photovoltaic cellsand printed electronic circuits in the near future.In short, PEDOT:PSS provides not only conductivitybut also flexibility combined with a high level oftransparency.Increasing conductivity is the key to opening upthe envelope for printed devices to become a reality.Dr Aloys Eiling, Managing Director of HC StarckClevios commented, "With emerging new technologiesthat require conductivity combined with transparencyand flexibility, Clevios(TM) PH1000 provides yet moretechnical opportunities than ever in OLED lighting andsolar cell applications as well as touch screen andrelated printed electronics uses."As the alternative to the state of the art transparentconductive coatings, mostly based on indium tin oxide(ITO), Clevios(TM) PH1000, an aqueous dispersion ofPEDOT:PSS, provides an easy-to-use solution to moveaway from expensive sputtering methods to wet printingprocesses.Providing crack resistant smooth thin films is a keyadvantage in many applications.~ Full Story @Examiner.comRead more…
This is where I am going to provide information on materials(and technologies) that might prove useful to drone-builders,and especially those drone-builders that are aiming at reallyhigh altitudes.
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