Polyimide chemistry

P84® - Unique fibre material manufactured by Evonik

Offering two types of speciality fibres, the core competency of Evonik is within polyimide fibres and polyimide design, with its products gaining widespread market acceptance.

The base material for P84® fibers is composed of aromatic backbone units only. Despite the non melting aromatic, halogen free structure it is classified as non flammable with an LOI of 38 percent.

Due to its outstanding chemical and physical properties P84® fibers are used for a variety of applications ranging from filter media for high temperature filtration, protective clothing, sealing materials for space craft to various high temperature applications such as heat insulation.

Evonik provides the polyimide P84® in various grades of fibers and pulp, solution and powder. If the requested grade is not listed below please contact us.

Staple Fiber

Titers
dtex
0.6
1.0
1.7
2.2
3.3
5.5
8.0
Cut Length
mm
60
60
53/60
53/60/80
60/80
60/80
60/80
Color
natural or spundyed
Packaging
Bales 200 kg

Filament Yarn

Titers
1060 dtex
Composition
480 single threads, 80 tpm Z
Color
natural
Packaging
12 cones at app. 3.5 kg/box

P84® Staple Fiber (2,2dtex) Typical Textile Data

Property
Test Method
Typical Value
Tenacity
 
38 cN/tex
Elongation at break
 
30%
Shrinkage at 240 °C, 10 minutes
 
<3%
Limiting Oxygen Index (LOI)
 
38%
Glass Transition Temperature (Tg)
DSC
315 °C
Density
 
1.41 g/cm

General Properties

P84® polyimide derived from aromatic dianhydrides and aromatic diisocyanates exhibits outstanding thermal stability. The polymer is non melting, has a glass transition temperature of 315 °C. The fibers start to carbonize at temperatures beyond 370 °C. Due to the aromatic structure the polymer and fibers are inherent non flammable. A limiting oxygen index of 38 percent can be measured. P84® can be used to temperatures up to 260 °C depending on the environment. 

Chemical Resistance

P84® polyimide is stable against most common organic solvents like alcohols, ethers, halogenated hydrocarbons or ethers. Strong polar, aprotic solvents like dimethyl formamide (DMF), dimethyl acetamide (DMAC) , N-methyl pyrrolidon (NMP) or concentrated sulphuric acid dissolve P84®.

P84® is sensitive to strong oxidizers like nitrogen dioxide at elevated temperatures. Strong concentrated aqueous acids such as sulfuric acid or concentrated aqueous Lewis Acids like zinc chloride affect P84®.

Fiber Properties

Features of the P84® polyimide fibers are the irregularly lobed cross-section being responsible for the high bulk of the fibers. The typical mechanical fiber data describe that P84® is rather a textile fiber with good knot and loop strength properties. Because of the low modulus and the high elongation P84® polyimide fibers are not destined for typical “reinforcing” applications as p-aramid or carbon fibers.