Quick Answer
CO, ECO and GECO are different epichlorohydrin polymer structures. CO emphasizes barrier performance; ECO balances barrier/flexibility; GECO adds cure/dynamic-performance flexibility.
CO vs ECO vs GECO
| Selection factor | CO | ECO | GECO |
|---|---|---|---|
| Polymer structure | Epichlorohydrin homopolymer | Epichlorohydrin + ethylene oxide copolymer | Epichlorohydrin + ethylene oxide + cure-site comonomer |
| Primary selection tendency | Barrier / low permeability | Balanced fuel resistance + flexibility | Dynamic/cure-system flexibility |
| Typical component direction | Barrier layers, fuel-vapor components | Fuel hose, seals, general automotive | Dynamic seals, hose and components requiring cure/dynamic tuning |
How to choose
Choose the polymer structure first, then the supplier grade. CO is a homopolymer; ECO is an ethylene-oxide copolymer; GECO commonly includes an allyl glycidyl ether cure-site monomer. The exact chemistry and trade-offs must be confirmed from the supplier TDS.
Frequently asked questions
No. It is different, not universally better. The extra monomer changes cure and dynamic behavior.
PECO is another modified epichlorohydrin family used by some suppliers for flexibility/low-temperature balance; confirm the exact supplier chemistry.