Viton™ GF-200S* fluoroelastomer is a 70% fluorine,  peroxide-cured fluoroelastomer similar to Viton™ GF-600S, but with a significantly lower gum polymer  viscosity of ~25 (ML at 121 °C [250 °F]). Viton™ GF-200S utilizes the latest technology from Chemours,  advanced polymer architecture (APA), which includes  a novel peroxide cure site along with an optimized  molecular weight distribution. 

Features 

• Excellent fluid resistance to aromatic hydrocarbons  and alcohols, including methanol, oils, steam, and acids 

• Is ideal for blending with Viton™ GF-600S to reach  intermediate viscosity ranges for injection molding 

• Improved mold release/mold fouling properties

• Improved mold flow and less shear sensitivity than  65 Mooney Viton™ GF-600S 

• Excellent physical properties with high elongation, both  original and aged 

• Heat, fluids, and low temperature properties  comparable to Viton™ GF and GF-600S 

• Improved water resistance/lower volume swell in water 

• Excellent compression set resistance with either low  or no post-cure

Processing 

A load factor of >72% for internal mixing of Viton™ GF-200S is suggested. The suggested process aids  for Viton™ GF-200S are 0.75 phr of Struktol® HT-290,  either alone or in combination with 0.5 phr of PAT-777,  or combinations of 0.5 phr Armeen® 18D with carnauba  wax or Struktol® WS-280. The use of TMAIC (trimethallyl  isocyanurate) is NOT suggested, as it causes poor mold  release and high compression set. Viton™ Curative No. 7  (VC-7) is the suggested coagent for all Viton™ GF-200S  compounds and is usually used at a 2.5 phr level or lower,  unless high modulus is needed. High levels of VC-7 can  bleed out and cause molding flaws.