10-04-2017, 09:41 PM
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Master Modeler
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Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 6,507
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Plastic propellant motors?
Hello All,
Has any model rocket company ever tried plastic-based (as opposed to synthetic rubber-based) solid propellants? The British produced LAP (Light Alloy [casing], Plastic [propellant]) military rocket motors in large quantities for decades, and many of them were used in Australian sounding rockets at the Woomera Range. The binder-fuel used in the LAP and LAPSTAR motors (“STAR” referred to the shape of the propellant grain void) was polyvinyl chloride (PVC) plastic. Polyurethane plastic (such as the polyurethane casting resins) could also be used as a fuel-binder. Also:
Such plastic propellants might work well in the same parallel-wound, rolled-paper motor casings that are used for black powder model rocket motors, as the liquid propellant—before it cured into a solid—would bind itself to the inner casing walls (clay or phenolic nozzles could be used in such plastic propellant motors). I had noticed that the polyurethane casting resins, when spilled (or deliberately poured) on cardboard or card stock before the mixed liquid resin cures, soaks into the upper layer of the material and bonds to it tenaciously.
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