High temperature mixed polyimides and composites formed therefrom
US5177180A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1990 |
| Grant date | Jan 5, 1993 |
| Priority date | — |
| Expiry date | Aug 7, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polyimide intercondensation products are prepared from mixed dianhydrides and aromatic diamines. One of the mixed dianhydrides must be 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride (6FDA) and the other dianhydride may be oxydiphthalic anhydride (ODPA) or biphenyl dianhydride (BPDA) or mixtures thereof. Preferred aromatic diamines are p-phenylenediamine (PPD) and/or m-phenylenediamine (MPD). The polyimide products have increased glass transition temperatures (Tg), frequently higher than 400.degree. C. Composites made from the polyimides have high thermal and oxidative stability and may be used in aircraft engine hardware.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.