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AssigneeThe United States of America as represented by the United States National Aeronautics and Space Administration
InventorsJohn W. Connell, Joseph G. Smith, Jr., Paul M. Hergenrother
Estimating the term…
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.
A process for reducing melt flow and increasing ease of processability of a host phenyethynyl containing polymer, which comprises:
A process for reducing melt flow and increasing ease of processability of a host phenyethynyl containing polymer, which comprises:
A process for reducing melt flow and increasing ease of processability of a host phenyethynyl containing polymer, which comprises:
A process for reducing melt flow and increasing ease of processability of a host phenyethynyl containing polymer, which comprises:
Dependencies are inferred from the claim text.