Structural materials and components

A process of making a structural component which includes the steps of assembling in a juxtaposed relationship a core material and a formulation that is convertible into a blocking material, said core material and said formulation each containing a polyimide precursor prepared by dissolving one or more primary diamines and 3,3',4,4'-benzophenonetetracarboxylic acid or an anhydride of that acid in essentially stoichiometric amounts in a lower alkyl alcohol, said formulation also including at least one filler, and the assembly being heated until said precursors are converted to polyimides and said blocking material is integrated with said core material.