USA As Represented by Secretary of the Navy

Bruce T Hartmann

Gilbert F Lee

John Lee

Harold C Wendt

John J Richardson, Jr

Jeffry J Fedderly

Karel Dusek

Jan Somvarsky

A series of polymeric compositions, methods of making the compositions and uses of the compositions are described. An exemplary composition is made by copolymerization of a trifunctional amine or hydroxy compound, a monofunctional amine or hydroxy compound and a polyisocyanate compound.

Polymer having network structure

A shock resistant dielectric material comprising TiO.sub.2 particles disped in a matrix material which is (1) the polyurea reaction product of a poly(tetramethylene ether)glycol-di-p-aminobenzoate prepolymer and an aromatic diisocyanate or (2) a blend of the polyurea reaction product and a cyanate ester homopolymer of bis(4-cyanatophenyl)-1,1-ethane.

Ceramic polymer composite dielectric material

A plurality of elongated test specimens undergo vibrations induced by ran noise within an acoustical frequency range establishing standing waves therein having resonant frequencies at which the collection of measurement data through accelerometers mounted at the ends of the specimens provides for calculation of physical material properties. The processing of the data during collection, analysis and calculation is automated by programmed computer control.

Material characterizing system

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Silver Spring, MD, United States of America

Bruce T Hartmann