Carbon-carbon composites of acceptable shrinkage and with negligible voids are prepared in a single casting step from acetylene-terminated Schiff's base monomers by melting a selected monomer, polymerizing it within a mold to form a green casting, and heating the casting to a carbonizing temperature. Blends of monomers may be used. Graphite may be admixed with the melted monomer to form a slurry before molding. Graphite in the form of woven ...
A composite for use on submarines and surface craft for controlling self-generated noise when listening with sonar. The composite includes two layers of PVF2 transducers separated by a layer of phase shifting or absorbing material. The inner transducer senses noise from the ship and subtracts this from the signal from the outer transducer representing noise plus the desired signal. In a second mode the sensed noise is regenerated through the ...