FabDigit

Cyanate Ester vs PBI and 2 more: properties

Cyanate EsterPBIBMIDAP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.1 GPa0.45 Msi
5.9 GPa0.86 Msi
4 GPa0.58 Msi
10.5 GPa1.5 Msi

Shear Modulus

1.2 GPa0.17 Msi
1.5 GPa0.21 Msi

Bulk Modulus

4 GPa0.52 Msi

Poisson's Ratio

0.35
0.34
0.35
0.32

Tensile Strength (Ultimate)

80 MPa11.6 ksi
160 MPa23.2 ksi
72 MPa10.4 ksi
55 MPa8 ksi

Elongation at Break

2.6%
3%
2%
0.6%

Compressive Strength

175 MPa25.4 ksi
400 MPa58 ksi
200 MPa29 ksi
200 MPa29 ksi

Compressive Modulus

3.3 GPa0.48 Msi
5.8 GPa0.84 Msi
4.1 GPa0.59 Msi

Flexural Strength

140 MPa20.3 ksi
220 MPa31.9 ksi
120 MPa17.4 ksi
105 MPa15.2 ksi

Flexural Modulus

3.2 GPa0.46 Msi
6.5 GPa0.94 Msi
4 GPa0.58 Msi
11 GPa1.6 Msi

Shear Strength

55 MPa8 ksi
100 MPa14.5 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

0.6 MPa·√m0.55 ksi·√in
0.6 MPa·√m0.55 ksi·√in

Izod Impact, Notched

20 J/m0.37 ft·lbf/in
32 J/m0.6 ft·lbf/in
18 J/m0.34 ft·lbf/in
40 J/m0.75 ft·lbf/in

Hardness, Shore D

89 Shore D

Hardness, Rockwell M

110 HRM
125 HRM
115 HRM
110 HRM

Physical

Density and transition temperatures.

Density

1.21 g/cm³0.04 lb/in³
1.3 g/cm³0.05 lb/in³
1.3 g/cm³0.05 lb/in³
1.8 g/cm³0.07 lb/in³

Glass Transition (Tg)

270°C518 °F
427°C801 °F
290°C554 °F
160°C320 °F

Water Absorption (24 h)

0.5%
0.4%
0.35%
0.2%

Water Absorption (Saturation)

2.3%
5%
4%
0.6%

Refractive Index

1.57

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.24 W/m·K0.14 BTU/hr·ft·°F
0.41 W/m·K0.24 BTU/hr·ft·°F
0.21 W/m·K0.12 BTU/hr·ft·°F
0.5 W/m·K0.29 BTU/hr·ft·°F

Specific Heat Capacity

1,150 J/kg·K0.27 BTU/lb·°F
1,000 J/kg·K0.24 BTU/lb·°F
1,150 J/kg·K0.27 BTU/lb·°F
1,050 J/kg·K0.25 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

63 µm/m·K35 µin/in·°F
23 µm/m·K12.8 µin/in·°F
40 µm/m·K22.2 µin/in·°F
25 µm/m·K13.9 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
310°C590 °F
230°C446 °F
180°C356 °F

Min Service Temperature

-200°C-328 °F
-196°C-321 °F
-70°C-94 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

265°C509 °F
300°C572 °F
285°C545 °F

Heat Deflection Temp. @ 1.8 MPa

250°C482 °F
435°C815 °F
280°C536 °F
265°C509 °F

Limiting Oxygen Index

33%
58%
38%
32%

Max Service Temperature (short-term)

300°C572 °F
500°C932 °F
300°C572 °F
230°C446 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in

Dielectric Strength

22 kV/mm559 V/mil
22 kV/mm559 V/mil
20 kV/mm508 V/mil
16 kV/mm406 V/mil

Dielectric Constant (1 MHz)

2.9
3.2
3.4
4.3

Dissipation Factor (1 MHz)

0.004
0.004
0.008
0.011

Volume Resistivity

1×10¹⁶ Ω·cm
1×10¹⁴ Ω·cm
1×10¹⁵ Ω·cm
1×10¹⁵ Ω·cm

Surface Resistivity

1×10¹⁵ Ω
1×10¹⁴ Ω
1×10¹⁴ Ω

Comparative Tracking Index (CTI)

200 V
200 V
200 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

82 / 100
92 / 100
85 / 100
80 / 100

UV / Weathering Resistance

30 / 100
70 / 100
35 / 100
55 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
50 / 100
50 / 100
40 / 100

Weldability

0 / 100
5 / 100
0 / 100
0 / 100

Formability (cold)

5 / 100
5 / 100
5 / 100
0 / 100

Polishability

65 / 100
55 / 100
60 / 100
45 / 100

Mold Shrinkage

0.6%
0.4%
0.4%

Processing Melt Temperature (typ.)

90°C194 °F
130°C266 °F

Mold Temperature (typ.)

180°C356 °F
190°C374 °F
160°C320 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

185 MJ/kg79,536 BTU/lb
190 MJ/kg81,685 BTU/lb
105 MJ/kg45,142 BTU/lb

Embodied Carbon (primary production)

9.5 kg CO₂/kg
9.5 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

66 kN·m/kg
123 kN·m/kg
55 kN·m/kg
31 kN·m/kg

Specific Stiffness (E / density)

2.6 MN·m/kg
4.5 MN·m/kg
3.1 MN·m/kg
5.8 MN·m/kg

Thermal Diffusivity

0.2 mm²/s
0.3 mm²/s
0.1 mm²/s
0.3 mm²/s

Same in both: Thermal Shock Resistance Index 0

Strength versus weight

Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scalePBI

Manufacturing and finishing

CapabilityCyanate EsterPBIBMIDAP
CNC machiningYes
Sheet metalYes
Injection moldingYes
Default conditionUnfilled
Relative cost$$$$ High$$$$$ Specialty$$$$ High$$$$ High
Min. machined wall0.5 mm
Best machined surfaceRa 0.8 µm
Chrome Plating (Plastic)Yes
EMI Shielding CoatingYes
PaintingYes
Soft Touch CoatingYes
Spray PaintingYes
UV CoatingYes

Ready to make it?

Upload a CAD file and FabDigit prices the part in Cyanate Ester and PBI side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.