HIGH TEMPERATURE POLYIMIDE MATRIX … 11/11...1 HIGH TEMPERATURE POLYIMIDE MATRIX COMPOSITES...
Transcript of HIGH TEMPERATURE POLYIMIDE MATRIX … 11/11...1 HIGH TEMPERATURE POLYIMIDE MATRIX COMPOSITES...
1
HIGH TEMPERATURE POLYIMIDE MATRIX COMPOSITES
Tsuyoshi Ozaki, Composites Research and DevelopmentKoji Moriuchi and Shinichi Sakane, IST Corporation
Satoshi Uehara and Takashi Yokoyama, Super Resin Inc.
2
Fiber reinforced plastic matrix composites
Very attractive materials
* Light-weight structures
* Especially for aerospace applications
Some of the aerospace parts such as engine componentsrequire high heat resistance of more than 200 ℃.
3
Polyimide resin as high temperature matrix
Epoxy
Bismaleimide5250-4, 5270-1 Less than 230 ℃
SKYBONDⓇⓇ 700, 703, 705
PMR-15 More than 300 ℃
Very attractive matrix for high temperature composites
High heat resistance
Polyimide
Less than 200 ℃
4
Major disadvantage of polyimide matrix resin
* The difficulty in polyimide curing process
* Imidization and curing happened simultaneously.⇒ High voids of more than 3 %⇒ Derade the mechanical and thermal performance
SolventSolvent
ImpregnationImpregnation LaminationLaminationHeatHeat
DryingDrying CuringCuring
HeatHeat
WaterWaterSolventSolvent
ImpregnationImpregnation LaminationLaminationHeatHeat
DryingDrying CuringCuring
HeatHeat
WaterWater(Imidization)
5
IST’s SKYBONDⓇⓇ 8000 and SKYBONDⓇⓇ 800
IST has developed new polyimide resins to solve the problem.2 solutions are proposed.
(1) SKYBONDⓇⓇ 8000 for RTM (Resin Transfer Molding)
Citraconic endcapped imide oligomer
(2) SKYBONDⓇⓇ 800 for two stage autoclave process
Citraconic endcapped amic acid oligomer
N NR’ RR
OO
n
O O
N N
O OO O
N NR’ RR
OO
n
O O
N N
OO OOO O
N NR’ RR
O
O
O
OOH
OOHO
n
O O
OHN N
HON NR’ RR
O
O
O
OOH
OOHO
n
O O
OHN N
HO
SKYBONDⓇⓇ 8000 for RTM
6
7
Resin Transfer Molding (SKYBONDⓇⓇ 8000)
SKYBONDⓇⓇ 8000 (Citraconic endcapped imide oligomer )
(1) Solvent free (imidized powder)
(3) Can be cured at >300 C
without volatiles
(2) Low melt viscosity (of less than 1.0 Pa・s)
N NR’ RR
OO
n
O O
N N
O OO O
m
N NR’ RR
OO
n
O O
N N
OO OOO O
m
N NR’ RR
OO
n
O O
N N
O OO O
N NR’ RR
OO
n
O O
N N
OO OOO O
0 100 200 300 400
1E+1
1E+2
1E+3
1E+41E+5
1E+6
Temperature (℃)
Visc
osity
(P)
0 100 200 300 400
1E+1
1E+2
1E+3
1E+41E+5
1E+6
Temperature (℃)0 100 200 300 400
1E+1
1E+2
1E+3
1E+41E+5
1E+6
0 100 200 300 400
1E+1
1E+2
1E+3
1E+41E+5
1E+6
0 100 200 300 400
1E+1
1E+2
1E+3
1E+41E+5
1E+6
Temperature (℃)
Visc
osity
(P)
Temperature Scan with 10℃/minFig.1
1.0 Pa・s
8
SKYBONDⓇⓇ 8000 molding & cure condition
Carbon Fabric 1) G30(0/90)n
Volume Fraction 48-50 %Injection Temp. 240 ℃Cure Temp. 335 ℃
200
250
300
350
0 100 200 300 400
335 ℃ x 4 h cure
Ramp Step 1 C/min
Injection & Hold Step
Time (min)
Tem
p. (℃
)
Table 1. Molding condition
Fig.1 Cure cycle
1) Desized at 400 C for 1hr
1.40 (0.29)48.5 (0.45)50.1 (0.38)40.7 (0.39)1.50 (0.00)Ave. (Std. Dev.)1.648.849.741.01.503
1.648.050.440.31.502
1.148.850.240.81.51Sample1
Voids (%)Resin Volume (%)Vf (%)Resin (wt%)Density (g/cc)
1.40 (0.29)48.5 (0.45)50.1 (0.38)40.7 (0.39)1.50 (0.00)Ave. (Std. Dev.)1.648.849.741.01.503
1.648.050.440.31.502
1.148.850.240.81.51Sample1
Voids (%)Resin Volume (%)Vf (%)Resin (wt%)Density (g/cc)
Fig.4 Microscopy of Cross Section
Fig.3 Ultrasonic C-scan-Poor
Good
Small amount of voidscompared with conventional polyimide composites
ASTM D3171
Table 2. Summary of the Acid Digestion
Void content of SKYBONDⓇⓇ 8000 RTM FRP
9
Calculated void content by digestion method
10
Flexural Strength of SKYBONDⓇⓇ 8000 FRP
0
20
40
60
80
100
120
StressModulus
Ret
entio
n R
ate
(%)
23℃ 180℃ 200℃ 220℃ 230℃ 240℃ 250℃
Stress 856.4 MPaModulus 48.1 MPa
n = 5 error bar = σ
Test Temp. (℃)
0
20
40
60
80
100
120
StressModulus
Ret
entio
n R
ate
(%)
23℃ 180℃ 200℃ 220℃ 230℃ 240℃ 250℃
Stress 856.4 MPaModulus 48.1 GPa
n = 5 error bar = σ
Fig.5 Flexural strength of SKYBONDⓇⓇ 8000Test Temp. (℃)
> 60 %
Only a small reduction
Good retention
SKYBONDⓇⓇ 800 for two stage autoclave process
11
12
Two stage cure autoclave process
ConventionalImidization stage and curing stage would overlap.
Imidization stage Curing stage1st 1st -- StageStage 2nd 2nd -- StageStage
Cure laminatesCure laminatesRemove volatiles Remove volatiles (solvent/water)(solvent/water)
Two stage cure for autoclave process
13
SKYBONDⓇⓇ 800 for two stage autoclave process
SkybondⓇⓇ 800 (Citraconic endcapped amic acid oligomer)
N NR’ RR
O
O
O
OOH
OOHO
n
O O
OHN N
HON NR’ RR
O
O
O
OOH
OOHO
n
O O
OHN N
HO
150 ℃ to 220 ℃
1st :Imidization stage
Imidization was completely
separated from curing stage
Laminates can be cured
without influence of water
N NR’ RR
OO
n
O O
N N
O OO O
N NR’ RR
OO
n
O O
N N
OO OOO O
N NR’ RR
OO
n
O O
N N
O OO O
m
N NR’ RR
OO
n
O O
N N
OO OOO O
m
> 300 ℃
2nd : Curing stage
Very unique resin for molding of composite laminates
having such a ‘two-stage’ cure cycle.
with NMP solvent
DSC (Differential scanning calorimetric analysis) of SKYBONDⓇⓇ 800
14
Fig.6 DSC thermograms of SKYBONDⓇⓇ 800 powder after it is dried
Metho d: imidizationdt 1 .0 0 s 30 .0 -40 0 .0°C 3 .00 °C/minSynchro nizatio n enabled
Sa mple: SK8 00 PAA powder.., 9 .0 4 00 mg
Co ntent 12 .0 8e+0 3 % no rma lized -12 0 .76 J g^-1Onset 13 4 .17 °CPea k 16 2 .63 °CLeft L imit 11 0 .34 °CRig ht L imit 23 2 .81 °C
m W
0
5
10
m in
°C50 100 150 200 250 300 350
0 20 40 60 80 100
^ e x o
S T A R e S W 9 . 2 0L a b : M E T T L E R
ImidizationCrosslink
Endothermic
220 ℃335 ℃165 ℃
Temperature
Hea
t flo
w
Exothermic
Imidization ratio of SKYBONDⓇⓇ 800
15
Table 3 Imidization ratio of SKYBONDⓇ 800
Conditions 1)Ratio 2)
1376 cm-1
/1500 cm-1
Imidizationratio(%)
150 ℃ -1 hr 0.740 0
150 ℃ -1 hr, 220 ℃ -30 min 1.000 71
150 ℃ -1 hr, 220℃ -1 hr 1.036 81
150 ℃ -1 hr, 220℃ -2 hrs 1.080 93
150 ℃ -1 hr, 220 ℃ -1 hr and 335 ℃ -4hr 1.106 100
1) Atmospheric pressure
2) 1376 cm-1: C-N streching of imide group
2) 1500 cm-1: C-N streching of para-benzene group
Tg of SKYBONDⓇⓇ 800 neat resin
16Fig.7 DMA of SKYBONDⓇⓇ 800 neat resin
2 stage cured film
296 ℃
Tensile properties of SKYBONDⓇⓇ 800 neat resin
17
Table 4 Tensile properties of SKYBONDⓇ 800 neat resin
Properties 23 ℃ 250 ℃ Measurement
Tensile strength 96 MPa 52 MPa ASTM D638
Tensile modulus 2.6 GPa 1.5 GPa ASTM D638
Elongation 5.6% 4.8% ASTM D638
Help to make the composite tougher than other brittle resin matrix like BMI.
About 5% elongation
SKYBONDⓇⓇ 800 FRP with two stage cure process
18
0
100
200
300
400
500
600
0 2 4 6 8 10 12
Time (hrs)
Tem
pera
ture
(℃
)
-12
-8
-4
0
4
8
12
Pre
ssur
e (k
gf/c
m2 )
Pressure : 10 kgf/cm2
2nd : 335 ℃4hrs
1st : 220 ℃1hr
Two stage cure cycle (full autoclave)
19
Full vacuum
Fig.8 Cure cycle
SKYBONDⓇⓇ 800 FRP and void content
20
Fig.9 SKYBONDⓇⓇ 800 GFRP and CFRP
Fig.10 Cross section of GFRP
Fig.11 Cross section of CFRP
Void content
(Digestion method)
< 0.5 %
GFRP KS1581,(0°45°‐45°90°)/s
Carbon fabric was desized at 400 ℃ for 1 hrCFRP G30, (0°60°‐60°)/s
Very low void content compared with conventional polyimide FRP
Void content
(Combustion method)
< 0.5 %
Tg of SKYBONDⓇⓇ 800 FRP
21
T e m p C e l4 0 0 .03 0 0 .02 0 0 .01 0 0 .00 .0
E' P
a
1 .0 E + 0 7
1 .0 E + 1 11 .0 E + 1 1
tanD
1 .0 0 0 0
0 .9 0 0 0
0 .8 0 0 0
0 .7 0 0 0
0 .6 0 0 0
0 .5 0 0 0
0 .4 0 0 0
0 .3 0 0 0
0 .2 0 0 0
0 .1 0 0 0
0 .0 0 0 0
E" P
a
1 .0 E + 0 6
1 .0 E + 1 21 .0 E + 1 2
2 9 1 .6C e l1 .2 E + 1 0P a
3 1 3 .8C e l0 .2 3 1 8
3 0 5 .4 C e l1 .2 E + 0 9P a
Fig.12 DMA of SKYBONDⓇⓇ 800 FRP Carbon fabric was desized at 400 ℃ for 1 hr
292 ℃
Short beam shear strength of SKYBONDⓇⓇ 800 FRP
22
Table 5 SBS strength of SKYBONDⓇ FRP
23 ℃ 200 ℃ Measurement
SBS strength 50 MPa 40 MPa ASTM D2344
Carbon fabric was desized.
Good bonding between resin and fiber
Free standing cure with SKYBONDⓇⓇ 800
23
Free standing cure
SKYBONDⓇⓇ 800 advantageImdization stage and curing stage of are completely separated.
* Free standing cureThe out-of-mold cure
* AdvantagesLess expensive toolsEpoxy-like autoclave cureDoes not require high temperature autoclave
24
Full autoclave Free standing cure1st stage in an autoclave in an autoclave2nd stage in an autoclave in an oven
Free standing cure of SKYBONDⓇⓇ 800800
25
Table 6 Free standing cure condition and Tg of SKYBONDⓇ 800 FRP
1st stage(Autoclave)
2nd stage(Free standing)
Tg
220 ℃ -6 hrs 300 ℃ -8 hrs 280 ℃
Carbon fabric was desized.
Fig.13 Cross section of free standing cured FRP
Carbon fabric G30, (0°60°‐60°)/s
Void content
(Digestion method)
< 0.5 %
SBS of free standing cured SKYBOND ⓇⓇ FRP 800
26
Free standing Full autoclave Measurement
SBS strength 40 MPa 50 MPa ASTM D2344
at 23 ℃
Table 7 Comparison of SBS strength of FRP between free standing cured and full autocalve molded
Good in spite of low pressurecompared with full autoclave process.
Summary
(1) Polyimide composite laminates with very low void content have been successfully fabricated both in the RTM process and the autoclave process.
(2) SKYBONDⓇⓇ 8000 composite laminates cured in RTM process have very good retention of mechanical and thermal properties at elevated temperature.
(3) SKYBONDⓇⓇ 800 resin for autoclave also exhibits excellent thermal stability. In addition, this resin provides the unique feature of “two stage” cure, which leads to vapour free cure in the second stage of the molding.
(4) Due to two stage process, SKYBONDⓇⓇ 800 enables fabricating polyimide composite laminates with “free standing cure”.
27
Acknowledgement
This work was partially supported by grant from JST (Japan Science and Technology Agency).
28