Phenylethynyl containing reactive additives

US6350817B1 · kind B1 · utility

Assignee

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

Inventors

• John W. Connell · Newport News, US
• Joseph G. Smith, Jr. · Smithfield, US
• Paul M. Hergenrother · Yorktown, US

Key dates

• Filing date: Apr 13, 1999
• Grant date: Feb 26, 2002
• Expiry date: Apr 13, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G73/10
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Phenylethynyl containing reactive additives were prepared from aromatic diamines containing phenylethynyl groups and various ratios of phthalic anhydride and 4-phenylethynylphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pyrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.