William J. Farrissey, Jr., James S. Rose and Peter S. Carleton, "Preparation of a Polyimide Foam, "Journal of Applied Polymer Science, Volume 14, 1970, p. 1093.
2.
R.A. Dine-Hart and W.W. Wright, "Preparation and Fabrication of Aromatic Polyimides,"Journal of Applied Polymer Science , Volume 11, Number 5, May 1965, p. 609.
3.
C.E. Sroog, A.L. Endrey, S.V. Abramo, C.E. Berr, W.M. Edwards, and K.L. Oliver, "Aromatic Polypyromellitimides From Aromatic Polyamic Acids,"Journal of Polymer Science, Volume 3, Part A, 1965, p. 1373.
4.
A. Wurtz, "Me'Moire Sur Les E'thers Cyaniques et Cyan uniques, et Sur la Constitution des Amides,"Annales DE Chimie ET DE Physique , Volume 42, Number 3, 1954, p. 54.
5.
J.A. Saunders and D.C. Frisch, Polyurethanes; Chemistry and Technology Part 1, Interscience Publishers, New York, 1963, p. 81,
6.
Ibid, 1963, p. 96.
7.
F.B. Dains, "Action of Certain Acid Reagents,"Journal of American Chemical Society, Volume 22, 1900, p. 186.
8.
C.D. Hurd and A.G. Prapas, Preparation of "Acyclic Imides"Journal of Organic Chemistry , Volume 24, 1969, p. 338.
9.
R.A. Meyers, "The Polymerization of Pyromellitic Dianhydride with Diphenylmethane Diisocyanate"Journal of Polymer Science, Volume 7, Number 10, Part A-1, 1969, p. 2757.
10.
Peter S. Carleton , North Branford, William J. Farissey, Jr. and James S. Rose, U.S. Patent3,701,756(October 31, 1973) to Upjohn Company.
11.
C.H. Smith and S.L. DeGisi, "Structural Application Characteristics of a Rigid Urethane Foam System,"Journal of Cellular Plastics, Volume 4, Number 10, October 1968, p. 386.
