What is polyimide fiber?
Polyimide (P84) is high strength and high modulus polyimide filament product. This product have excellent mechanical properties, while maintaining the inherent flame retardant, high temperature carbonization instead of melt, very low combustion flew gas and almost non-toxic, high and low temperature resistance, radiation resistance, chemical resistance, good dimensional stability, good interface combination and other characteristics. The products are mainly used in aerospace, structural materials, electrical and electronic, special cables and other fields.
Polyimide (PI, P84) properties
Limiting oxygen index more than 38, good radiation resistance, strength 3.8cN/dtex, elongation 32%, modulus 35cN/dtex, density 1.41g/cm, boiling water and 250℃ shrinkage are less than 0.5% and 1% respectively.
High strength and high modulus, UV resistance. Polyimide has high temperature resistance, low temperature resistance, radiation resistance, flame retardancy and non-toxicity, and has excellent mechanical properties, dimensional stability, chemical stability and biocompatibility. No dripping, self-extinguishing when removed from fire and excellent thermal insulation.
- Polyimide fiber has good spinnability.
- Polyimide combines warmth retention, antibacterial, far-infrared and other functions.
- Polyimide has excellent thermal stability, and its decomposition temperature is generally around 500°C.
- Polyimide can withstand extremely low temperatures, such as not brittle in liquid helium at -269°C, and has extremely high heat resistance above 450°C.
- Polyimide varieties are insoluble in organic solvents and stable to dilute acids.
- Polyimide has good dielectric properties, with a dielectric constant of about 3.4. Polyimide is a self-extinguishing polymer with low smoke generation rate.
- Due to the low thermal expansion coefficient, the thermal expansion is small and the dimensional stability is high.
Mechanical properties Comparison of mechanical indexes between polyimide fiber, Vectran and PPTA
| Item |
Unit |
Vectran |
|
PPTA |
Polyimide |
| HT |
UM |
Standard |
UM |
| Density |
g/cm³ |
1.41 |
1.44 |
1.44 |
1.45 |
1.42 |
| Breaking strength |
Gpa |
3.2 |
2.9 |
2.8 |
2.8 |
3.0-3.8 |
| Breaking elongation |
% |
3.8 |
2.7 |
2.9 |
2.3 |
1.5-3.5 |
| Elasticity modulus |
cN/dtex |
530 |
740 |
493 |
774 |
650-1000 |
Aging resistance Comparison of aging resistance between polyimide fiber and other high performance fiber:
Thermal stability Polyimide heat resistance test:
Glass transition temperature 330℃，5%thermal weight loss 550℃
Applications of polyimide (PI, P84)
- High-performance aerostats.
- Optical cable reinforcement and special cables.
- Marine non-metallic pipelines.
- High-performance cable sheaths, functional and structurally integrated composite materials.
