Crosslinking Chemistry for Fluorocarbon Ether Bibenzoxazole Polymers
Abstract
Curable and hydrolytically stable FEB copolymers were synthesized by the acetic acid-promoted copolycondensation of tetrafluoroethylene oxide: hexafluoropropylene oxide-derive dithioimidate esters with fluorocarbon ether bis(o-aminophenol) monomers and a fluorocarbon bis(o-aminophenol) monomer containing an aliphatic hydrocarbon cure site. The structure of the cure site monomer was molecularly tailored to possess sufficient solubility and reactivity during the polycondensation reactions to permit incorporation of the appropriately structured cure sites into the FEB copolymer backbone. Thermogravimetric analysis and isothermal aging studies indicated high thermooxidative stability almost comparable to analogous FEB polymers void of the hydrocarbon cure sites. Isothermal aging in air at 260C (500F) and 288C (550F) for 200 hours led to weight losses of 7 and 17 percent, respectively. Preliminary formulation and curing studies demonstrated the reactivity of the cure sites to radical-induced cure reactions. Based on the low temperature viscoelastic properties, the high thermooxidative and hydrolytic stability, as well as the ready curability of the FEB copolymers, a broader use temperature range capability than currently available in state-of-the-art elastomer materials is envisioned.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA079798
Entities
People
- R. C. Evers
- T. Abraham
Organizations
- Air Force Research Laboratory