CA1255544A - Carbon fiber strength - Google Patents
Carbon fiber strengthInfo
- Publication number
- CA1255544A CA1255544A CA000540393A CA540393A CA1255544A CA 1255544 A CA1255544 A CA 1255544A CA 000540393 A CA000540393 A CA 000540393A CA 540393 A CA540393 A CA 540393A CA 1255544 A CA1255544 A CA 1255544A
- Authority
- CA
- Canada
- Prior art keywords
- yarn
- fibers
- fiber
- resin
- precursor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 229920000049 Carbon (fiber) Polymers 0.000 title claims abstract description 19
- 239000004917 carbon fiber Substances 0.000 title claims abstract description 19
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 18
- 239000011347 resin Substances 0.000 claims abstract description 30
- 229920005989 resin Polymers 0.000 claims abstract description 30
- 239000002243 precursor Substances 0.000 claims abstract description 23
- XPFVYQJUAUNWIW-UHFFFAOYSA-N furfuryl alcohol Chemical group OCC1=CC=CO1 XPFVYQJUAUNWIW-UHFFFAOYSA-N 0.000 claims description 47
- 238000006116 polymerization reaction Methods 0.000 claims description 15
- 239000003054 catalyst Substances 0.000 claims description 13
- 230000004584 weight gain Effects 0.000 claims description 8
- 235000019786 weight gain Nutrition 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 7
- 238000005470 impregnation Methods 0.000 claims description 3
- 238000011065 in-situ storage Methods 0.000 claims description 2
- 230000000379 polymerizing effect Effects 0.000 claims description 2
- 239000000835 fiber Substances 0.000 description 70
- HYBBIBNJHNGZAN-UHFFFAOYSA-N furfural Chemical compound O=CC1=CC=CO1 HYBBIBNJHNGZAN-UHFFFAOYSA-N 0.000 description 11
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 9
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- WTEOIRVLGSZEPR-UHFFFAOYSA-N boron trifluoride Chemical compound FB(F)F WTEOIRVLGSZEPR-UHFFFAOYSA-N 0.000 description 5
- QUSNBJAOOMFDIB-UHFFFAOYSA-N Ethylamine Chemical compound CCN QUSNBJAOOMFDIB-UHFFFAOYSA-N 0.000 description 4
- 238000003763 carbonization Methods 0.000 description 4
- -1 e.g. Substances 0.000 description 4
- 229910015900 BF3 Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 239000007859 condensation product Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical group O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 102220586009 ATP-dependent Clp protease proteolytic subunit, mitochondrial_I20S_mutation Human genes 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 241000518994 Conta Species 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000012262 resinous product Substances 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000012956 testing procedure Methods 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
- D01F11/10—Chemical after-treatment of artificial filaments or the like during manufacture of carbon
- D01F11/14—Chemical after-treatment of artificial filaments or the like during manufacture of carbon with organic compounds, e.g. macromolecular compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Ceramic Products (AREA)
- Reinforced Plastic Materials (AREA)
- Inorganic Fibers (AREA)
- Chemical Treatment Of Fibers During Manufacturing Processes (AREA)
Abstract
TITLE
Improvement of Carbon Fiber Strength Abstract Carbon fibers from pitch are treated with carbonizable resin precursor and carbonized to give an improvement in carbon fiber strength.
Improvement of Carbon Fiber Strength Abstract Carbon fibers from pitch are treated with carbonizable resin precursor and carbonized to give an improvement in carbon fiber strength.
Description
TITLE
Improvement of Carbon Fiber Strength Background of the Invention The production of carbon fiber from pitch is well known. See, for example, U.S. Patent N~s.
4,005,183 and 4,504,454. It is believed that the maximum tenacity which these fibers are capable of achieving is not attained due in part to defects in the fibers and/or at the fiber surface. The present invention seeks to enhance the fiber tenacity of such fibers.
Summary of the Invention This invention provides a method for increasing the tenacity of pitch-based carbon fiber yarn comprising impregnating a pitch-based carbonized or partially carbonized fiber yarn with a carbonizable resin precursor, polymerizing the precursor in situ to form the resin and subjecting the impregnated yarn to a temperature in excess of 1000C in an inert atmosphere to carbonize the resin.
; Detailed Description of the Invention ;
The carbon fiber yarn to be strengthened in accordance with the present invention is a pitch-based yarn. This yarn may be prepared by the general procedures described in UOS~ Patent No.
4,005,183. Eitber carbonized or partially carbonized yarn may be employed.
A ~olution of a carbonizable resin precursor ~ is applied to the yarn. The object is to impregnate the fibers of the yarn with a material which will polymerize or polymerize further to a resinous product which will remain in place and leave a carbon residue within the fiber upon carbonization. Thus, ~255544 the term "resin precursor" is intended to include unpolymerized or partially polymerized materials.
Polymerization or resinification is often facilitated by application of heat. The resin must be capable of being carbonized, the usual temperature of carbonization being above 1000Co Among suitable carbonizable resin precursors are partially polymerized phenolic condensation products, epoxy resins, furfural, furfuryl alcohol, partially polymerized furfuryl alcohol resin, urea condensation products, acrylic resins, vinyl resins, propylene glycol, etc. A sufficient amount of carbonizable resin precursor must be absorbed by the yarn to provide strengthening. Amounts yielding between about 0.1 and 10% of resin based on the weight of the yarn prior to impregnation have been found satisfactory. Preferably the weight gain is kept below 5~, particularly with partially carbonized fiber because such fibers are less able to absorb the resin precursors.
It is preferred that the resin precursor have a high coking factor, that is, a high percentage of carbon yield when subjected to carbonization.
Volatile impregnants which are entirely driven off in the heatinq step are clearly unsuitable.
The yarn is passed through a bath containin~
the carbonizable resin precursor. If the resin prerur~or is furfuryl alcohol, a partially polymerized furfuryl alcohol or combination thereof, it is desirable to incorporate a latent catalyst along with the precursor. These are commercially available and recommended for the purpose of catalyzing the polymerization of the resin precursor at elevated temperatures. One such catalyst is a complex of boron trifluoride and monoethylamine.
.
~:~S5S44L
Another catalyst is maleic anhydride. Use of a latent catalyst permits application of a low viscosity solution to the fiber with subsequent polymerization at the elevated temperatures. If the precursor were to polymerize significantly prior to application, the treating bath would be so viscous as to allow only a coating to be formed. Under such circumstances, the ~ibers of the yarn would stick to each other and become damaged or adversely affected for use in composites where penetration of matrix medium between the yarn fibers is of utmost importance. Suitable solvents are those which will readily evaporate without leaving any harmful residues. Acetone has been found useful for this purpose.
As mentioned above, the viscosity of the impregnation bath should be sufficiently low as to permit permeation of the resin precursor into the fibers of the yarn, i.e., to fill the voids, cracks and other defects of the fiber. If the bath is too viscous, the yarn itself, rather than the fibers thereof, will entrap such amounts of resin precursor I as to cause the fibers to ~tick tv each other. Such I fibers often break when attempts are made to separate them from each other. It will be understood that the resin content of the impregnating solution increases with age because partial polymerization is taking place. As this occurs, the viscosity of the bath increases and will influence the degree of fiber permeation.
Upon removal of the yarn from the bath, excess surface fluid is gently removed as by padding with an absorbent material to avoid damaging the yarn. Exposure of the yarn to air at room ~ 5~
temperature for extended periods allows solvents from the impregnating solution to evaporate and the resin precursor to partially cure. Alternatively, this may be achieved by slowly heating the yar~ from room temperature to final polymerization temperatures. In any event, the yarn must be heated to completely polymerize the impregnant. Conditions for such polymerization arle well known in the art.
In general, the yarn will !be heated to temperatures in the range of about 100 to 200C for periods of at least five minutes. Following this polymerization, the yarn is subjected to carbonization conditions, namely, treatment in an inert atmosphere, e.g., nitrogen, argon, etc., at temperatures of above 1000C until the resin has carbonized.
Testing Procedures Tenacity, elongation and modulus (T/E/M~ are measured according to ASTM D-3379-75.
The following examplcs are submitted to illustrate the invention and are not intended as l limiting. In each case, the pitch-based yarn was ! impregnated by passage through a bath containing the resin precursor.
1 The yarn conta;ned 496 filaments each having `~ 25 a diameter of about 10 microns. The carbonized yarn (at 1600C~ had an initial modulus of about 900 to ~000 grem~ per denier ~gpd).
Example 1 Carbon fiber yarn was impregnated with furfuryl alcohol containing 1~ latent catalyst (commercially available complex of boron trifluoride and monoethylamine ~BF3.MEA). The fibers were heated at 4C/min. to 150~C and held at 150C for 32 minutes ~2~;S544 : to polymerize the furfuryl alcohol. After polymerization the fibers were found to have gained 1.45% of their original weight. The fibers were then carbonized at 15B4C. An 11% improve~ent in tensile strength over the control fiber resulted tT/E/rl impregnated fiber: 14.6gpd/1.22%/1055gpd, T/~/M
control fiber: 13.2gpd/1.17~/988 gpd).
Example 2 Carbon fiber yarn was impregnated with the solution used in Example 1. The solution had been aged for 22 days. The furfuryl alcohol was polymerized under the same conditions as in Example 1. After polymerization, the fibers were found to have gained 8.7~ of their original weight. The fibers were then recarbonized at 1584C. A 22%
improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber:
16.1gpd/1.25~/997gpd, T/E/M control fiber:
13.2gpd~1.17~/988gpd).
Example 3 Carbon fiber yarn was impregnated using a 90/10% by wt. mixture of furfuryl alcohol and furfural ~odified furfuryl alcohol resin with 2~ of the latent catalyst of Example 1. The fibers were heated at 4C/min~ to 120~C and held at 120C for 32 minutes to polymerize the furfuryl alcohol/resin.
.fter polymerization, the fibers were found to have gained 3.2~ of their original weight. The fiber~
were then recarbonized at 1600C. A 29% improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 14.2gpd/1.23%/10259pd, T/E/M c~ntrol fiber: ll.Ogpd/.95~/1081gpd).
Example 4 Carbon fiber yarn was impregnated using a 3l;æ~i;~5~4 90/10% by wt. mixture of furfuryl alcohol and furfural modified furfuryl alcohol resin with 2% of-the latent catalyst of Example 1. The fibers were heated at 4C/min to 120 and held at 120C for 32 minutes to polymerize the iEurfural modified resin.
After polymerization, the Eibers were found to have gained 6.1% of their original weight. The fibers - were then recarbonized at 1600C. A 24~ improvement in tensile strength over the control fiber resulted (T/E/M impregnated iber: 15.1gpd/1.18~/1148gpd, T/E/M control fiber: 12.2gpd/1.023%/lOg5gpd).
Example 5 Carbon fiber yarn was impregnated using a 10~ by wt. solution of furfural modified furfuryl alcohol resin dissolved in acetone. The fibers were then heated at 4C/min to 120C and held at 120C for 32 minutes. The resulting weight gain was 7.7~ of j their original weight. The fibers were recarbonized at 1600C. A 12~ improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 15.0gpd/1.41%/945, T/E/M control fiber:
13.4gpd/1.34~/868gpd).
Example 6 - Comparative Example i Carbon fiber yarn was impregnated using acetone containing 5% of the latent catalyst of Example 1. The fibers were then heated to 4C/min to j 120C. and held at 120C for 32 minutes. The i resultins weight gain was less than 1~. The fibers were then recarbonized at 1600C. No increase in strength resulted (T/E/M impregnated fiber:
13.7gpd/1.13%/1131gpd, T/E/M control fiber:
14.~gpd/1.07%/1272gpd). This example shows treatment with a non-resin forming medium did not result in strength improvement.
~25ss~4 Example 7 Carbon fiber yarn was impregnated using propylene glycol containing 5% of the latent catalyst of Example 1. The fibers were then heated at 4C/min to 200C and held at 200C for 32 minutes. A resin was formed from propylene glycol under these conditions. The resulting weight gain was less than 1%. The fibers were then recarbonized at 1600C. A
10% improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 13.2gpd/
1.05%/1133gpd, T/E/M control fiber:
12.Ogpd/.947%/1141gpd).
Example 8 Partially carbonized yarn (heated to 1000C~
was impregnated with furfuryl alcohol containing 2%
of the latent catalyst of Example 1 which had been aged 72 hours. The fibers were heated at 4C/min to 120C and held at 120C for 32 minutes to polymerize the furfuryl alcohol. The resulting weight gain was less than 1%. The fibers were then oarbonized at 1599C. A 24.5~ improvement in tensile strength over the control fiber resulted. (T/E/M impregnated fiber: 14.5gpd/1.18~/1083gpd, T/E/~ control fiber:
l 11.6gpd/97%/1080gpd~.
! 25 Example 9 Carbon fiber was impresnated with furfural containing 2% of the catalyst of Example 1. The fibers were heated at 4C/min to 120CC and held at I20C for 32 minutes to polymerize the furfural.
~ 30 After polymerization, the fibers were found to have gained 0.1% of their original weiqht (weight gain from dipping was 3~ he fibers were then recarbonized at 1600C. A 14% improvement in tensile ~trength over the control fiber resulted (T/~/M
- ~255544 impregnated fiber: 13.8gpd/1.06%/1194gpd, T/E/M
control fiber: 12.2gpd/1.023%/1095gpd).
Exampl~ 10 Carbon fiber was impregnated using a 95/5%
by wt. mixture of furfuryl alcohol and furfural modified furfuryl alcohol resin with 5~ maleic anhydride added as a latent catalyst. The fibers were heated at 4C/min to 120C and held at 120C for 32 minutes to polymerize the furfuryl alcohol/resin.
After polymerization, the fibers were found to have gained 6.1~ of their ori~inal weight ~weight gain aftçr dipping was 160%). The fibers were then recarbonized at 1594C. A 20% improvement in tensile strength over the control fiber resulted ~T/E/M
impregnated fiber: 14.6gpd/1.17%/1155gpd, T/E/M
control fiber: 12.2gpd/1.02%/1087gpd).
Improvement of Carbon Fiber Strength Background of the Invention The production of carbon fiber from pitch is well known. See, for example, U.S. Patent N~s.
4,005,183 and 4,504,454. It is believed that the maximum tenacity which these fibers are capable of achieving is not attained due in part to defects in the fibers and/or at the fiber surface. The present invention seeks to enhance the fiber tenacity of such fibers.
Summary of the Invention This invention provides a method for increasing the tenacity of pitch-based carbon fiber yarn comprising impregnating a pitch-based carbonized or partially carbonized fiber yarn with a carbonizable resin precursor, polymerizing the precursor in situ to form the resin and subjecting the impregnated yarn to a temperature in excess of 1000C in an inert atmosphere to carbonize the resin.
; Detailed Description of the Invention ;
The carbon fiber yarn to be strengthened in accordance with the present invention is a pitch-based yarn. This yarn may be prepared by the general procedures described in UOS~ Patent No.
4,005,183. Eitber carbonized or partially carbonized yarn may be employed.
A ~olution of a carbonizable resin precursor ~ is applied to the yarn. The object is to impregnate the fibers of the yarn with a material which will polymerize or polymerize further to a resinous product which will remain in place and leave a carbon residue within the fiber upon carbonization. Thus, ~255544 the term "resin precursor" is intended to include unpolymerized or partially polymerized materials.
Polymerization or resinification is often facilitated by application of heat. The resin must be capable of being carbonized, the usual temperature of carbonization being above 1000Co Among suitable carbonizable resin precursors are partially polymerized phenolic condensation products, epoxy resins, furfural, furfuryl alcohol, partially polymerized furfuryl alcohol resin, urea condensation products, acrylic resins, vinyl resins, propylene glycol, etc. A sufficient amount of carbonizable resin precursor must be absorbed by the yarn to provide strengthening. Amounts yielding between about 0.1 and 10% of resin based on the weight of the yarn prior to impregnation have been found satisfactory. Preferably the weight gain is kept below 5~, particularly with partially carbonized fiber because such fibers are less able to absorb the resin precursors.
It is preferred that the resin precursor have a high coking factor, that is, a high percentage of carbon yield when subjected to carbonization.
Volatile impregnants which are entirely driven off in the heatinq step are clearly unsuitable.
The yarn is passed through a bath containin~
the carbonizable resin precursor. If the resin prerur~or is furfuryl alcohol, a partially polymerized furfuryl alcohol or combination thereof, it is desirable to incorporate a latent catalyst along with the precursor. These are commercially available and recommended for the purpose of catalyzing the polymerization of the resin precursor at elevated temperatures. One such catalyst is a complex of boron trifluoride and monoethylamine.
.
~:~S5S44L
Another catalyst is maleic anhydride. Use of a latent catalyst permits application of a low viscosity solution to the fiber with subsequent polymerization at the elevated temperatures. If the precursor were to polymerize significantly prior to application, the treating bath would be so viscous as to allow only a coating to be formed. Under such circumstances, the ~ibers of the yarn would stick to each other and become damaged or adversely affected for use in composites where penetration of matrix medium between the yarn fibers is of utmost importance. Suitable solvents are those which will readily evaporate without leaving any harmful residues. Acetone has been found useful for this purpose.
As mentioned above, the viscosity of the impregnation bath should be sufficiently low as to permit permeation of the resin precursor into the fibers of the yarn, i.e., to fill the voids, cracks and other defects of the fiber. If the bath is too viscous, the yarn itself, rather than the fibers thereof, will entrap such amounts of resin precursor I as to cause the fibers to ~tick tv each other. Such I fibers often break when attempts are made to separate them from each other. It will be understood that the resin content of the impregnating solution increases with age because partial polymerization is taking place. As this occurs, the viscosity of the bath increases and will influence the degree of fiber permeation.
Upon removal of the yarn from the bath, excess surface fluid is gently removed as by padding with an absorbent material to avoid damaging the yarn. Exposure of the yarn to air at room ~ 5~
temperature for extended periods allows solvents from the impregnating solution to evaporate and the resin precursor to partially cure. Alternatively, this may be achieved by slowly heating the yar~ from room temperature to final polymerization temperatures. In any event, the yarn must be heated to completely polymerize the impregnant. Conditions for such polymerization arle well known in the art.
In general, the yarn will !be heated to temperatures in the range of about 100 to 200C for periods of at least five minutes. Following this polymerization, the yarn is subjected to carbonization conditions, namely, treatment in an inert atmosphere, e.g., nitrogen, argon, etc., at temperatures of above 1000C until the resin has carbonized.
Testing Procedures Tenacity, elongation and modulus (T/E/M~ are measured according to ASTM D-3379-75.
The following examplcs are submitted to illustrate the invention and are not intended as l limiting. In each case, the pitch-based yarn was ! impregnated by passage through a bath containing the resin precursor.
1 The yarn conta;ned 496 filaments each having `~ 25 a diameter of about 10 microns. The carbonized yarn (at 1600C~ had an initial modulus of about 900 to ~000 grem~ per denier ~gpd).
Example 1 Carbon fiber yarn was impregnated with furfuryl alcohol containing 1~ latent catalyst (commercially available complex of boron trifluoride and monoethylamine ~BF3.MEA). The fibers were heated at 4C/min. to 150~C and held at 150C for 32 minutes ~2~;S544 : to polymerize the furfuryl alcohol. After polymerization the fibers were found to have gained 1.45% of their original weight. The fibers were then carbonized at 15B4C. An 11% improve~ent in tensile strength over the control fiber resulted tT/E/rl impregnated fiber: 14.6gpd/1.22%/1055gpd, T/~/M
control fiber: 13.2gpd/1.17~/988 gpd).
Example 2 Carbon fiber yarn was impregnated with the solution used in Example 1. The solution had been aged for 22 days. The furfuryl alcohol was polymerized under the same conditions as in Example 1. After polymerization, the fibers were found to have gained 8.7~ of their original weight. The fibers were then recarbonized at 1584C. A 22%
improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber:
16.1gpd/1.25~/997gpd, T/E/M control fiber:
13.2gpd~1.17~/988gpd).
Example 3 Carbon fiber yarn was impregnated using a 90/10% by wt. mixture of furfuryl alcohol and furfural ~odified furfuryl alcohol resin with 2~ of the latent catalyst of Example 1. The fibers were heated at 4C/min~ to 120~C and held at 120C for 32 minutes to polymerize the furfuryl alcohol/resin.
.fter polymerization, the fibers were found to have gained 3.2~ of their original weight. The fiber~
were then recarbonized at 1600C. A 29% improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 14.2gpd/1.23%/10259pd, T/E/M c~ntrol fiber: ll.Ogpd/.95~/1081gpd).
Example 4 Carbon fiber yarn was impregnated using a 3l;æ~i;~5~4 90/10% by wt. mixture of furfuryl alcohol and furfural modified furfuryl alcohol resin with 2% of-the latent catalyst of Example 1. The fibers were heated at 4C/min to 120 and held at 120C for 32 minutes to polymerize the iEurfural modified resin.
After polymerization, the Eibers were found to have gained 6.1% of their original weight. The fibers - were then recarbonized at 1600C. A 24~ improvement in tensile strength over the control fiber resulted (T/E/M impregnated iber: 15.1gpd/1.18~/1148gpd, T/E/M control fiber: 12.2gpd/1.023%/lOg5gpd).
Example 5 Carbon fiber yarn was impregnated using a 10~ by wt. solution of furfural modified furfuryl alcohol resin dissolved in acetone. The fibers were then heated at 4C/min to 120C and held at 120C for 32 minutes. The resulting weight gain was 7.7~ of j their original weight. The fibers were recarbonized at 1600C. A 12~ improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 15.0gpd/1.41%/945, T/E/M control fiber:
13.4gpd/1.34~/868gpd).
Example 6 - Comparative Example i Carbon fiber yarn was impregnated using acetone containing 5% of the latent catalyst of Example 1. The fibers were then heated to 4C/min to j 120C. and held at 120C for 32 minutes. The i resultins weight gain was less than 1~. The fibers were then recarbonized at 1600C. No increase in strength resulted (T/E/M impregnated fiber:
13.7gpd/1.13%/1131gpd, T/E/M control fiber:
14.~gpd/1.07%/1272gpd). This example shows treatment with a non-resin forming medium did not result in strength improvement.
~25ss~4 Example 7 Carbon fiber yarn was impregnated using propylene glycol containing 5% of the latent catalyst of Example 1. The fibers were then heated at 4C/min to 200C and held at 200C for 32 minutes. A resin was formed from propylene glycol under these conditions. The resulting weight gain was less than 1%. The fibers were then recarbonized at 1600C. A
10% improvement in tensile strength over the control fiber resulted (T/E/M impregnated fiber: 13.2gpd/
1.05%/1133gpd, T/E/M control fiber:
12.Ogpd/.947%/1141gpd).
Example 8 Partially carbonized yarn (heated to 1000C~
was impregnated with furfuryl alcohol containing 2%
of the latent catalyst of Example 1 which had been aged 72 hours. The fibers were heated at 4C/min to 120C and held at 120C for 32 minutes to polymerize the furfuryl alcohol. The resulting weight gain was less than 1%. The fibers were then oarbonized at 1599C. A 24.5~ improvement in tensile strength over the control fiber resulted. (T/E/M impregnated fiber: 14.5gpd/1.18~/1083gpd, T/E/~ control fiber:
l 11.6gpd/97%/1080gpd~.
! 25 Example 9 Carbon fiber was impresnated with furfural containing 2% of the catalyst of Example 1. The fibers were heated at 4C/min to 120CC and held at I20C for 32 minutes to polymerize the furfural.
~ 30 After polymerization, the fibers were found to have gained 0.1% of their original weiqht (weight gain from dipping was 3~ he fibers were then recarbonized at 1600C. A 14% improvement in tensile ~trength over the control fiber resulted (T/~/M
- ~255544 impregnated fiber: 13.8gpd/1.06%/1194gpd, T/E/M
control fiber: 12.2gpd/1.023%/1095gpd).
Exampl~ 10 Carbon fiber was impregnated using a 95/5%
by wt. mixture of furfuryl alcohol and furfural modified furfuryl alcohol resin with 5~ maleic anhydride added as a latent catalyst. The fibers were heated at 4C/min to 120C and held at 120C for 32 minutes to polymerize the furfuryl alcohol/resin.
After polymerization, the fibers were found to have gained 6.1~ of their ori~inal weight ~weight gain aftçr dipping was 160%). The fibers were then recarbonized at 1594C. A 20% improvement in tensile strength over the control fiber resulted ~T/E/M
impregnated fiber: 14.6gpd/1.17%/1155gpd, T/E/M
control fiber: 12.2gpd/1.02%/1087gpd).
Claims (5)
1. A method for improving the tenacity of pitch-based carbon fiber comprising impregnating pitch-based carbon fiber yarn or partially carbonized yarn with a carbonizable resin precursor, polymerizing the precursor in situ to form the resin and subjecting the impregnated yarn to a temperature in excess of 1000°C in an inert atmosphere to carbonize the resin.
2. The method of claim 1 wherein the precursor is furfuryl alcohol.
3. The method of claim 1 wherein the precursor is partially polymerized furfuryl alcohol.
4. The method of claim 1 wherein a sufficient amount of precursor has been absorbed by the yarn to provide a weight gain after polymerization of between 0.1% and 10% based on the weight of the yarn prior to impregnation.
5. The method of claim 1 wherein a latent catalyst is employed to catalyze polymerization of the precursor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87821786A | 1986-06-25 | 1986-06-25 | |
| US878,217 | 1986-06-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255544A true CA1255544A (en) | 1989-06-13 |
Family
ID=25371603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000540393A Expired CA1255544A (en) | 1986-06-25 | 1987-06-23 | Carbon fiber strength |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0251596A1 (en) |
| JP (1) | JPS636115A (en) |
| AU (1) | AU7458587A (en) |
| CA (1) | CA1255544A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02221159A (en) * | 1989-02-23 | 1990-09-04 | Mitsubishi Pencil Co Ltd | Production of carbon fiber reinforced carbon composite material |
| JPH0416556A (en) * | 1990-05-11 | 1992-01-21 | Nippon Oil Co Ltd | Manufacturing method of carbon/carbon composite material |
| JPH0416555A (en) * | 1990-05-11 | 1992-01-21 | Nippon Oil Co Ltd | Production of carbon-carbon composite material |
| GB9202486D0 (en) * | 1992-02-06 | 1992-03-25 | Dunlop Ltd | Carbon-carbon composite material |
| JP5483701B2 (en) | 2010-02-08 | 2014-05-07 | 日曹金属化学株式会社 | Zinc based alloy |
| US9550701B2 (en) | 2013-07-25 | 2017-01-24 | Honeywell International Inc. | Carbon-carbon composites including isotropic carbon encapsulating layer and methods of forming the same |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3908061A (en) * | 1972-03-10 | 1975-09-23 | Dow Chemical Co | Composite materials comprising resin matrix and carbon fibers |
| US4115528A (en) * | 1977-08-15 | 1978-09-19 | United Technologies Corporation | Method for fabricating a carbon electrode substrate |
-
1987
- 1987-06-19 EP EP87305466A patent/EP0251596A1/en not_active Withdrawn
- 1987-06-22 AU AU74585/87A patent/AU7458587A/en not_active Abandoned
- 1987-06-23 JP JP15458387A patent/JPS636115A/en active Pending
- 1987-06-23 CA CA000540393A patent/CA1255544A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0251596A1 (en) | 1988-01-07 |
| JPS636115A (en) | 1988-01-12 |
| AU7458587A (en) | 1988-01-07 |
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