Maleimido substituted aromatic cyclotriphosphazenes

US4550177A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Devendra Kumar · Rochester Hills, US
• George M. Fohlen · Millbrae, US
• John A. Parker · Los Altos, US

Key dates

• Filing date: Apr 11, 1984
• Grant date: Oct 29, 1985
• Expiry date: Apr 11, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/315
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.