Viton ™ VTR-9209 is a precompound containing an improved 69% fluorine ”B-type” fluoroelastomer. This precompound incorporates a bisphenol cure system that can be optionally compounded with peroxide and coagent for “dual curing.” Viton ™ VTR-9209 offers a unique combination of processing and cured characteristics
including:

• High quality, smooth extrudate surface and appearance at thickness less than 1.0 mm (0.040 in)
• Excellent ”green” strength that helps maintain extrudate shape, as well as enabling draw down to very thin veneer thicknesses
• Excellent fuel permeation resistance
• Good tensile strength
• Good adhesion to other elastomers in multilayer hoses

Viton ™ VTR-9209 is especially attractive for use in the manufacture of low permeation fuel and filler neck hose for automotive and small engine applications. It also works well for any hose requiring a thin FKM layer. This product is superior in extrusion processability, compared to many other types of Viton ™ , including Viton ™ B-202 and B-600 blends.

When used at a 1–1.5 phr level, Carnauba wax and VPA 2 process aids each create a smooth finish and result in good metal release. Combinations of these process aids with Struktol ® WS280 can provide other desirable characteristics to some compounds. Viton ™ VTR-9209 is not suggested for use in applications above 250 °C
(482 °F).

The heat resistance of VTR-9209 can be maximized by the use of a dual cure system of VC-7 and peroxide in conjunction with the incorporated bisphenol cure. See compound three in Table 1 for a dual cure example.