BALLISTIC SCALE-UP OF NF PROPELLANTS. III. LINER DEVELOPMENT.
ROHM AND HAAS CO HUNTSVILLE AL REDSTONE RESEARCH LABS
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A liner based on asbestos-filled polyester resins was used successfully for lining eighteen 6 X 18-inch motors and one 9.1 X 41-inch motor in the scale-up program with NF propellant. There were two major limitations of these liners 1 the liner had to be in a partially cured state at the time the propellant was cast and 2 the liner-to-metal bond failed in case-bond tests after a limited storage at high temperature. Excellent bonding to propellant was obtained when motors were processed with NL-10 liner using prescribed procedures. NF propellant bonded well to phenolic resin-asbestos liner, in small-scale bond tests. Storage for 20 weeks at 135 F has not affected the bond of the propellant to the liner. The limitations of this liner were 1 surface preparation was critical in the 6 X 18-inch motor, with grit blasting and thorough degreasing required, and 2 propellant curing was inhibited by volatile substances present in insulation which had not been postcured sufficiently. Sprayable bonding lacquers based on copolymers of methyl acrylate andor methyl methacrylate with acrylic acid were developed. These lacquers were used successfully on steel, phenolic resin-asbestos, and butyl rubber substrates, and showed promise of good storage capability. These lacquer systems show the greatest potential usefulness of the three materials discussed. Author
- Laminates and Composite Materials
- Rocket Engines