Abstract Porous carbon structures such as honeycomb and reticulated carbon foam contain cavities or interstices which are filled with cellular carbon foam to provide thermal insulating products having relatively high strength-to-weight ratios and structural integrity at high temperatures. A tenacious bond between the carbon foam and the porous carbon structure is attained by impregnating the porous structure with partially polymerized furfuryl alcohol, curing the latter, and then filling the cavities with a carbon foam formulation which includes a binder of partially polymerized furfuryl alcohol. After the foam producing reaction and the curing of the binder the filled structures are heated to a temperature sufficient to carbonize the furfuryl alcohol. The partially polymerized furfuryl alcohol employed as the impregnant and the binder provides the bond between the porous structure and the carbon foam filler.
The method of fabricating a carbon composite as claimed in claim 1, including the additional steps of successively impregnating the framework and curing the resin after each impregnation prior to filling the interstices with the foam producing admixture.
Claim 2
Dependent Claim
21 words
The method of fabricating a carbon composite as claimed in claim 1, wherein the thermosetting resin is partially polymerized furfuryl alcohol.
Claim 3
Dependent Claim
27 words
The method of fabricating a carbon composite as claimed in claim 3, wherein the carbonaceous framework and the foam in the framework interstices comprise rigid polyurethane foam.
Claim 4
Dependent Claim
28 words
The method of fabricating a carbon composite as claimed in claim 4, wherein the foam producing admixture comprises a two-component urethane system interactable to produce a cellular foam.
Claim 5
Dependent Claim
30 words
The method of fabricating a carbon composite as claimed in claim 1, wherein the configuration of the carbonaceous framework is selected from the group consisting of honeycomb and reticulated foam.
Claim 6
Dependent Claim
27 words
The method of fabricating a carbon composite as claimed in claim 1, wherein the framework is in a carbonized state prior to impregnating with said thermosetting resin.
Claim 7
Dependent Claim
29 words
The method of fabricating a carbon composite as claimed in claim 6, wherein the foam producing admixture consists essentially of said resin and hollow microspheres formed of said resin.
Claim 8
Dependent Claim
49 words
The method of fabricating a carbon composite as claimed in claim 6, wherein the framework is formed of at least two layers of reticulated foam having a different number of interstices per unit area, and wherein the layers are bonded together by the resin impregnant upon the curing thereof.