Preparation of carbonaceous pyropolymers

Carbonaceous pyropolymers possessing recurring units containing at least carbon and hydrogen atoms composited on a solid support may be prepared in a solid state process. The process is effected by treating a high surface area solid support such as an inorganic oxide as exemplified by alumina with an organic monomer which is capable of being polymerized by thermal, ionic, or free radical polymerization methods. The monomer is polymerized on the surface of the support under polymerization conditions and thereafter the polymer-coated support is subjected to pyrolysis at temperatures ranging from about 600.degree. to about 1200.degree. C. to form a carbonaceous pyropolymer. If so desired, this composite may then be subjected to the action of a dissolving agent under conditions which will dissolve or leach out the solid support, thus leaving a carbonaceous pyropolymer possessing recurring units containing at least carbon and hydrogen atoms.

BACKGROUND OF THE INVENTION 
Heretofore, carbonaceous pyropolymers which are composited on a solid 
support have been prepared by subjecting a solid support to contact with a 
pyropolymer precursor at an elevated temperature, said pyropolymer 
precursor being in a gaseous state. For example, U.S. Pat. No. 3,651,386 
discloses a method for preparing such a composition in which a porous 
refractory oxide material is positioned as a bed in a vessel which is 
provided with heating means, and the pyrolyzable substance in a carrier 
gas is passed downward through the refractory oxide bed at an elevated 
temperature whereby a carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms is composited on the solid 
refractory oxide. Another method of preparing such a composition is found 
in U.S. Pat. No. 3,997,689 in which refractory oxide materials are 
introduced into the reaction section which may comprise a boring screw 
reactor. In this reactor, the inorganic refractory oxide material is 
contacted with a gassified hydrocarbon while maintaining the support 
material in a semi-fluidized state. 
The methods of preparing the desired composition according to these prior 
patents necessitates the use of relatively expensive equipment which is 
needed for a gas phase pyrolysis. As will hereinafter be shown in greater 
detail, it has now been discovered that a carbonaceous pyropolymer 
possessing recurring units containing at least carbon and hydrogen atoms 
composited on a solid support may be prepared in a solid state process 
utilizing relatively inexpensive equipment such as simple furnaces. By 
utilizing such equipment, it is possible to reduce the overall cost of the 
finished product and thus render the product more readily available for 
various uses of the type hereinafter set forth in greater detail. 
SUMMARY OF THE INVENTION 
This application relates to a process for preparing compositions of matter 
comprising a carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms composited on a solid 
support. More specifically, the invention is concerned with a process for 
preparing a carbonaceous pyropolymer possessing recurring units containing 
at least carbon and hydrogen atoms composited on a solid support utilizing 
a solid state preparation. The compositions of matter which are prepared 
according to the process of this invention will find a wide variety of 
uses in the chemical field. For example, the compositions which will 
possess semi-conducting properties may be used for electrical applications 
such as heterojunction transistors, field-effect transistors, thermo 
elements in thermoelectric generators, refrigerators, temperature-sensing 
devices, as electrodes in electrochemical cells, memory devices, inductive 
elements and in separations applications. 
The particular composition of matter comprising a carbonaceous pyropolymer 
possessing recurring units containing at least carbon and hydrogen atoms 
composited on a solid support which is prepared according to the process 
of this invention will have particular use in applications for the 
separation of liquids. The material which is produced according to the 
present process will possess a pore size and pore volume which is 
different from that which is possessed by the solid support upon which the 
carbonaceous pyropolymer is composited. As will hereinafter be shown in 
greater detail, material resulting from the process of this invention will 
possess pore sizes which are lower or less in diameter than those of the 
original substrate and will have an increased pore volume in the small 
pore sizes. For example, the number of pores in the range of from 0 to 1.6 
nanometers (nm) will be increased and will comprise a substantial part or 
portion of the total pores in the material. This large number of small 
pores will be of interest inasmuch as material may then be used in 
separation applications in place of other supports such as activated 
carbon. This is particularly advantageous inasmuch as activated carbons 
are usually prepared by a relatively complicated process involving a 
plurality of steps or operations, thereby contributing to a higher cost of 
operation. 
It is therefore an object of this invention to provide a process for 
preparing carbonaceous pyropolymers possessing recurring units containing 
at least carbon and hydrogen atoms composited on a solid support. 
A further object of this invention is to provide a solid state process for 
preparing compositions of matter which are useful in a wide variety of 
applications. 
In one aspect, an embodiment of this invention is found in a solid state 
process for the preparation of a carbonaceous pyropolymer possessing 
recurring units containing at least carbon and hydrogen atoms composited 
on a solid support, which comprises admixing an organic monomer capable of 
being polymerized with a high surface area solid support, polymerizing 
said monomer at polymerization conditions, pyrolyzing the resultant 
polymer-coated solid support at pyrolysis conditions, and recovering the 
resultant high surface area carbonaceous pyropolymer possessing recurring 
units containing at least carbon and hydrogen atoms composited on a solid 
support. 
A specific embodiment of this invention is found in a solid state process 
for the preparation of a carbonaceous pyropolymer possessing recurring 
units containing carbon and hydrogen atoms composited on a solid support 
which comprises admixing divinylbenzene with gamma-alumina in the presence 
of azo-bis-isobutyronitrile, polymerizing said monomer at temperatures 
from about ambient to about 250.degree. C. and a pressure in the range of 
from about atmospheric to about 100 atmospheres, pyrolyzing the resultant 
polymer-coated alumina at a temperature in the range of from about 
600.degree. to about 1200.degree. C. and a pressure in the range of from 
about atmospheric to about 100 atmospheres, and recovering the resultant 
carbonaceous pyropolymer possessing recurring units containing at least 
carbon and hydrogen atoms composited on gamma-alumina. 
Other objects and embodiments will be found in the following further 
detailed description of the present invention. 
DETAILED DESCRIPTION OF THE INVENTION 
As hereinbefore set forth, the present invention is concerned with a 
process for preparing a carbonaceous pyropolymer possessing recurring 
units consisting of at least carbon and hydrogen atoms composited on a 
solid support utilizing a solid state method for the preparation thereof. 
As was previously discussed, this type of composition has been prepared by 
vaporizing a hydrocarbon and thereafter pyrolyzing the vaporous 
hydrocarbon onto the surface of the solid support or substrate. In 
contradistinction to this, the present process employs a different 
technique in which the pyropolymer precursor comprises a monomer which is 
capable of being polymerized by thermal, ionic, or free radical 
polymerization methods. In general, the solid support or substrate is 
contacted with a monomer solution following which the monomer is 
polymerized on the surface of the support. Following the polymerization, 
the resulting composite is then pyrolyzed to decompose the polymer and 
form the desired carbonaceous pyropolymer. The solid support which is 
utilized in the process of this invention preferably comprises an 
inorganic refractory oxide which may be in any form. For example, the 
refractory oxide may be in the form of loose or compacted dry powders, 
cast or calcined sols, heated sols, flats, cylinders, spheres, pellets, 
rods, etc. Again, in the preferred embodiment of the invention the 
inorganic refractory oxide will possess a relatively high surface area in 
the range of from about 1 to about 500 m.sup.2 /g. Some specific examples 
of these inorganic refractory oxides will include alumina, particularly 
gamma-alumina, theta-alumina, silica, or mixtures of inorganic refractory 
oxides such as silica-alumina. It is to be understood that these examples 
of supports or substrates which may be employed are only representative of 
the class of compounds which may be used and that the present invention is 
not necessarily limited thereto. 
Examples of organic monomers which may be employed to produce the polymeric 
coating of the solid support prior to pyrolysis of the composite will 
include such compounds as styrene, divinylbenzene, phenolformaldehyde 
resins, acrylonitrile-styrene resins, allyl resin monomers, epoxy resins, 
melamine-formaldehyde resins, polyester resins, polyimide resins, 
polyurethane resins, polycarbonate resins, etc. Again, as in the case of 
the solid supports, the list of polymerizable monomers is only 
representative of the type of compounds which may be employed as 
pyropolymer precursors and that the present invention is not necessarily 
limited thereto. 
The process may be effected by contacting the solid support of the type 
hereinbefore set forth in greater detail with a solution of the organic 
monomer. In addition, if so desired, the admixture of the solid support 
and inorganic monomer may also contain a polymerization initiator as an 
aid to polymerization, an example of such an initiator being 
azo-bis-isobutyronitrile. The polymerization of the organic monomer is 
effected at polymerization conditions which will include a temperature in 
the range of from about ambient to about 250.degree. C. and a pressure in 
the range of from about atmospheric to about 100 atmospheres. The 
polymerization of the monomer is allowed to proceed for a period of time 
which may range from about 1 to about 100 hours or more, the particular 
polymerization time being dependent upon the organic monomer undergoing 
polymerization as well as the operating parameters of temperature and 
pressure. Following the completion of the polymerization process, the 
polymer-coated substrate is recovered and subjected to pyrolysis, whereby 
the polymer is converted to a carbonaceous pyropolymer possessing 
recurring units containing at least carbon and hydrogen atoms. Pyrolysis 
conditions which are employed to produce the desired composition will 
include temperatures in the range of from about 600.degree. to about 
1200.degree. C. as well as pressures ranging from about atmospheric to 
about 100 atmospheres. In the preferred embodiment of the invention, the 
pyrolysis is effected in the presence of an inert or reducing gas such as 
nitrogen, helium, argon or hydrogen, the pyrolysis being effected for a 
period of time sufficient to convert the polymer to the carbonaceous 
pyropolymer and usually in a range of from about 0.5 to about 4 hours or 
more. 
If so desired, the resulting composition comprising a carbonaceous 
pyropolymer possessing recurring units consisting of at least carbon and 
hydrogen atoms composited on a solid support may be further treated in 
such a manner so that the solid support is dissolved and removed, thereby 
leaving only the carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms. The removal of the solid 
support is effected by leaching, utilizing either an acid or a base as the 
dissolving agent. The dissolution or leaching of the base material may be 
effected over a wide range of temperatures, said range being from about 
ambient (20.degree.-25.degree. C.) up to about 250.degree. C. or more for 
a period of time which may range from about 2 to about 72 hours or more in 
duration. It is to be understood that the operating parameters of the 
leaching or dissolving step will vary over a wide range and will be 
dependent upon a combination of time, temperature, strength of the 
leaching solution, etc. Examples of acids or bases which may be utilized 
to dissolve out the base material, that is, the refractory inorganic oxide 
will include inorganic acids such as phosphoric acid, sulfuric acid, 
nitric acid, hydrochloric acid; organic acids such as methylsulfonic acid, 
ethylsulfonic acid, propylsulfonic acid, toluenesulfonic acid, etc. or 
strong bases such as sodium hydroxide, potassium hydroxide, lithium 
hydroxide, rubidium hydroxide, cesium hydroxide, etc. It is to be 
understood that the aforementioned dissolving agents are only 
representative of the class of compounds which may be used and that any 
chemical which may be capable of removing the refractory inorganic oxide 
while (1) retaining the high surface area of the carbonaceous pyropolymer 
and (2) retaining the particle size or particular shape of the original 
substrate may be employed. 
The process of the present invention may be effected in any suitable manner 
and may comprise a batch or continuous type of operation. For example, 
when a batch type operation is employed, a quantity of the high surface 
area solid support such as gamma-alumina in the shape of spheres, rods, 
pellets, etc. may be placed in an appropriate apparatus. A solution of an 
organic monomer is also placed in the vessel along with, if so desired, a 
polymerization initiator following which the impregnation of the support 
with the monomer is effected in a vacuum. After impregnating the monomer 
on the surface of the substrate for a period of time sufficient to control 
the amount of monomer on the surface of the substrate, the excess solution 
of the material is then removed by filtration. The material is then 
allowed to polymerize on the surface of the support utilizing 
predetermined polymerization conditions, i.e. temperature, pressure, 
reaction period, etc. Following the polymerization of the monomer on the 
support, the polymer-coated support or substrte is placed in an 
appropriate apparatus such as a quartz tube whereby the carbonaceous 
pyropolymer is formed by means of pyrolysis. The pyrolysis is effected by 
heating the vessel in an appropriate apparatus such as a furnace under the 
flow of an inert gas of the type hereinbefore set forth. Upon completion 
of the pyrolysis period, the desired composition comprising a carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms composited on a solid support may be recovered. 
In the event that the removal of the substrate is desired, the carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms composited on a solid support may then be placed in a 
leaching bath whereby it is contacted with a dissolving agent of the type 
hereinbefore set forth under conditions selected to dissolve the support. 
The dissolution of the solid support is effected under conditions which 
will preferably include an elevated temperature for a period of time 
sufficient to dissolve substantially all of the solid support. 
It is also contemplated within the scope of this invention that the 
composition of matter may be prepared in a solid state manner utilizing a 
continuous method of operation. When such a type of operation is employed, 
the components of the finished composition comprising a solid support or 
substrate and the organic monomer are continuously charged to a reaction 
vessel which is maintained at the proper operating conditions of 
temperature and pressure. After passage through the vessel for a period of 
time sufficient to effect the polymerization of the monomer and produce a 
polymer-coated support, the reaction mixture is continuously withdrawn 
from the vessel and the excess solution is separated from the 
polymer-coated support. The latter is then continuously charged to a 
pyrolysis zone wherein pyrolysis of the polymer to form the desired 
carbonaceous pyropolymer is effected in the presence of an inert gas at 
pyrolysis conditions similar to those hereinbefore set forth. After 
passage through the pyrolysis zone for a time sufficient to effect the 
desired pyrolysis, the composition is continuously withdrawn therefrom and 
recovered. Alternatively, if further treatment of the carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms composited on a solid support is desired, the composition 
is continuously charged to a leaching or dissolution vessel wherein it is 
contacted with a dissolving agent capable of dissolving the substrate. 
Again, after passage through this vessel for a period of time sufficient 
to effect the dissolution of the substrate, the product comprising the 
carbonaceous pyropolymer possessing recurring units containing at least 
carbon and hydrogen atoms is continuously withdrawn, separated from the 
leaching or dissolving agent, and recovered. 
The desired compositions of matter comprising either a carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms composited on a solid support or a carbonaceous pyropolymer 
possessing recurring units containing at least carbon and hydrogen atoms 
which has been obtained by dissolving out the substrate will possess 
physical properties which will make them desirable for a wide variety of 
uses. As was hereinbefore set forth, the carbonaceous pyropolymers will 
possess pore sizes which are smaller in diameter than the pore sizes of 
the original substrate as well as possessing an increased pore volume in 
the small pore sizes. In addition to their use as a semiconducting 
material, the carbonaceous pyropolymers may also be utilized in 
separations applications. This use is due to the fact that the 
carbonaceous pyropolymers will possess a substantial portion of the 
surface area of the material in micropores of less than about 1.6 
nanometers in diameter. This characteristic will impart a molecular sieve 
character to the materials and thus permit the use thereof as components 
in the separation of various liquids.

The following examples are given for purposes of illustrating the process 
of this invention as well as the characteristics of the products obtained 
from the process. However, it is to be understood that these examples are 
given merely for purposes of illustration and that the present process is 
not necessarily limited thereto. 
EXAMPLE I 
In this example, 20.31 grams of 1/8" gamma-alumina spheres were placed in a 
Teflon bottle along with a solution containing 38 ml of p-diethylbenzene, 
8.85 grams of divinylbenzene and 0.0495 grams of a polymerization 
initiator comprising azo-bis-isobutyronitrile. The bottle was sealed, 
placed in a mineral oil bath and heated at a temperature of 50.degree. C. 
for a period of 72 hours to polymerize the divinylbenzene on the alumina 
substrate. At the end of the polymerization period, heating was 
discontinued and the excess solution was separated from the polymer-coated 
alumina by means of filtration. The recovered composite was then placed in 
a quartz glass tube and the tube was placed into a vertical furnace. The 
tube was gradually heated to a temperature of 800.degree. C. at a rate of 
50.degree. C. per 15 minutes, the pyrolysis being effected in the presence 
of a stream of nitrogen which was charged to the tube at a rate of 250 ml 
per minute. Upon reaching 800.degree. C., the composite was pyrolyzed for 
a period of 1 hour at this temperature and thereafter was allowed to 
return to room temperature. The composite comprising a carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms composited on alumina was recovered an analyzed. The 
results of this analysis are set forth in Table I below: 
TABLE I 
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Overall Weight Increase (%) 
17.8 
C (wt-%) 17.21 
H (wt-%) 0.67 
BET Surface Area (m.sup.2 /g) 
98 
Pore Volume (mL/g) 0.27 
Average Pore Diameter (nm) 
11.0 
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EXAMPLE II 
In this example, 19.19 grams of 1/8" gamma-alumina spheres along with a 
solution of 46.76 grams of divinylbenzene and 0.0459 grams of a 
polymerization initiator comprising azo-bis-isobutyronitrile were placed 
in a Teflon bottle which was thereafter sealed. The bottle was placed in a 
mineral oil bath and heated to a temperature in the range of from about 
60.degree. to about 65.degree. C. for a period of 48 hours. At the end of 
the 48 hour period, heating was discontinued, the excess hydrocarbon 
mixture was separated from the composite and the polymer-coated spheres 
were dried slightly on a hot plate in a flowing nitrogen atmosphere. The 
sample was weighed and 26.44 grams of polymeric material was found on the 
spheres. Following this, the composite was loaded into a quartz tube which 
was placed in a verticle tube furnace. As in Example I, the material was 
slowly heated to a temperature of 800.degree. C. at a rate of 50.degree. 
C. per 15 minutes, the heating being effected in a nitrogen flow of about 
250 ml per minute. Upon reaching 800.degree. C., the sample was pyrolyzed 
at this temperature for a period of 1 hour following which heating was 
discontinued and the carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms composited on alumina was 
recovered. The carbonaceous pyropolymer deposition appeared to be uniform 
over the surface of the alumina and analysis of the composite produced the 
results set forth in Table II below: 
TABLE II 
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Overall Weight Increase (%) 
23.2 
C (wt-%) 23.99 
H (wt-%) 0.70 
BET Surface Area (m.sup.2 /g) 
272 
Pore Volume (mL/g) 0.19 
Average Pore Diameter (nm) 
2.5 
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EXAMPLE III 
As an illustration of the physical properties which are possessed by 
carbonaceous pyropolymers possessing recurring units containing at least 
carbon and hydrogen atoms, 1/8" gamma-alumina spheres were contacted with 
a solution of divinylbenzene and a polymerization initiator comprising 
azo-bis-isobutyronitrile. After allowing the polymerization of the 
divinylbenzene to proceed for a period of about two days by heating the 
mixture at 60.degree. C., the polymer-coated alumina was recovered. 
Pyrolysis was effected by subjecting the material to a temperature of 
800.degree. C. for a period of 1 hour in a nitrogen atmosphere. The 
physical properties of the resultant carbonaceous pyropolymer possessing 
recurring units containing at least carbon and hydrogen atoms composited 
on alumina were measured and the material was then treated with an 85% 
phosphoric acid solution at a temperature of 160.degree. C. for a period 
of about 20 hours to dissolve out the gamma-alumina support. At the end of 
this period, the carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms was recovered, washed, 
heated in the water for a period of two hours at 80.degree. C., again 
washed with deionized water and dried. Again, the physical characteristics 
or properties of the carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms were measured. The results 
of these measurements are set forth in Table III below: 
TABLE III 
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Original Pyrolysis 
Leached 
Gamma-Alumina 
Product 
Product 
__________________________________________________________________________ 
BET Surface Area (m.sup.2 /g) 
166 272 1320 
Pore Vol. (ml/g) (pores &lt;30.0 nm 
0.44 0.17 1.68 
diameter) 
Average Pore Dia. (nm) (pores &lt; 
10.7 2.5 5.1 
30.0 nm diameter) 
Calculated Surface Area (m.sup.2 /g) 
145 55 465 
(pores 1.6 to 30.0 nm 
diameter) 
Peak Crush Strength (kg) 
11.6 7.6 &lt;0.5 
Average Crush Strength (kg) 
7.5 4.0 &lt;0.5 
__________________________________________________________________________ 
In addition, it was also found that the pyrolysis product contained 23.99 
wt. % of carbon and 0.70 wt. % of hydrogen. 
EXAMPLE IV 
To illustrate the difference in properties between composites which have 
been prepared according to prior art methods and the method of the present 
invention, a carbonaceous pyropolymer possessing recurring units 
containing at least carbon and hydrogen atoms composited on a solid 
support was prepared by treating alumina with benzene at a temperature of 
800.degree. C. The resulting composite comprised a 1.0 to 2.0 nm dense 
film of pyropolymer deposited on 5.0 nm alumina crystallites. A second 
composite was prepared by impregnating alumina with divinylbenzene at a 
temperature of 60.degree. C. to form a polymeric film on the alumina. This 
composite was then heated at a temperature of 800.degree. C. to pyrolyze 
the polymer and form a composite comprising an ultra-micropore pyropolymer 
deposited in the alumina pore structure. A comparison of the properties of 
the two composites is set forth in Table IV below in which the 
conventional pyropolymer is designated "A" and the pyropolymer of the 
present invention is designated "B". 
TABLE IV 
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AL.sub.2 O.sub.3 
A B 
______________________________________ 
Carbon (wt. %) 
-- 25.32 23.99 
Surface Area (m.sup.2 /g) 
166 (BET) 113 (BET) 272 (Langmuir) 
(eqn.) 
Pore Volume (ml/g) 
0.44 0.24 0.17 
(pores &lt;30.0 nm dia- 
meter) 
Pores 1.6-30.0 nm 
N.sub.2 Adsorption 
Pore Volume (ml/g) 
0.43 0.23 0.10 
Surface Area (m.sup.2 /g) 
148 92 55 
Average Pore 11.6 10.0 7.3 
Diameter (nm) 
Pores 0-1.6 nm 
N.sub.2 Adsorption 
Pore Volume (ml/g) 
0.01 0.01 0.07 
Surface Area (m.sup.2 /g) 
18 21 217 
Average Pore 2.2 1.9 1.3 
Diameter (nm) 
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EXAMPLE V 
As a further illustration of the variants found between the conventional 
composite and the composite of the present invention, the two carbonaceous 
pyropolymers possessing recurring units containing at least carbon and 
hydrogen atoms composited on a high surface area support were subjected to 
a leaching step wherein the composite was contacted with H.sub.3 PO.sub.4 
at a temperature of 160.degree. C. whereby the alumina substrate was 
dissolved and recovered. After drying, the two composites were analyzed 
and the results set forth in Table V below in which the carbonaceous 
pyropolymer possessing recurring units containing at least carbon and 
hydrogen atoms which had been prepared according to the conventional 
method was designated "A" and the carbonaceous pyropolymer possessing 
recurring units containing at least carbon and hydrogen atoms prepared 
according to the process of the present invention was designated "B". 
TABLE V 
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Al.sub.2 O.sub.3 
A B 
______________________________________ 
Surface Area (m.sup.2 /g) 
166 1142 (BET) 1740 
(eqn.) (BET) (Langmuir) 
Pore Volume (ml/g) 
0.44 2.52 1.65 
Pores &lt;30.0 nm dia- 
meter) 
Pores 1.6-30.0 nm 
N.sub.2 Adsorption 
Pore Volume (ml/g) 
0.43 2.51 1.26 
Surface Area (m.sup.2 /g) 
148 1142 586 
Average Pore Diameter 
11.6 8.3 8.6 
Pores 0-1.6 nm 
N.sub.2 Adsorption 
Pore Volume (ml/g) 
0.01 0.01 0.39 
Surface Area (m.sup.2 /g) 
18 0 1154 
Average Pore Diameter 
2.2 Not Applicable 
1.3 
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It is therefore readily apparent from a comparison of the two materials in 
Table IV and V herein that the composites prepared according to the 
process of the present invention possess a distinctly different structure 
with regard to pore size and pore volumes, that is, pores of smaller 
diameter and increased pore volume of said smaller pores, than did those 
composites which had been prepared according to the conventional methods 
of operation. 
EXAMPLE VI 
In a similar manner, other inorganic oxides such as silica or 
silica-alumina may also be treated with other organic monomers such as 
styrene or a phenol-formaldehyde resin by free radical or ionic 
polymerization mechanisms to form polymers on the surface of the inorganic 
oxide. The polymer-coated inorganic oxides may then be subjected to a 
pyrolysis step in the solid state at a temperature which may range from 
about 600.degree. to about 1200.degree. C. for a period of time ranging 
from 1 to 4 hours to form a carbonaceous pyropolymer possessing recurring 
units containing at least carbon and hydrogen atoms composited on the 
inorganic oxide support. These carbonaceous pyropolymers may then, if so 
desired, be further subjected to the action of a dissolving agent whereby 
the inorganic oxide support may be dissolved and removed from the 
resulting carbonaceous pyropolymer possessing recurring units containing 
at least carbon and hydrogen atoms.