Aromatic heterocyclic polymer alloys and products produced therefrom
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsThaddeus E. Helminiak, Charles L. Benner, Fred E. Arnold, George E. Husman
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Abstract
Rod-like aromatic heterocyclic polymers are used as reinforcement in coil-like heterocyclic polymer matrices to provide composites at the molecular level that are analogous to chopped fiber composites.
Claims12
A polymeric alloy comprising a mixture of a flexible, coil-like heterocyclic polymer and a reinforcing amount of a rod-like aromatic heterocyclic polymer, the coil-like heterocyclic polymer consisting essentially of repeating units having the following structural formulas:
- ##STR7## wherein X is NH, N.phi., O or S, where .phi. is phenyl, Ar' is ##STR8## and m is an integer having a value such that the polymer has an intrinsic viscosity of about 2 to 20 dl/g as determined in methanesulfonic acid at 30.degree. C., and the rod-like aromatic heterocyclic polymer consisting essentially of repeating units having the following formulas:
- ##STR9## where X is NH, N.phi., O or S, where .phi. is phenyl, Ar is ##STR10## and n is an integer having a value such that the polymer has an intrinsic viscosity of about 5 to 30 dl/g as determined in methanesulfonic acid at 30.degree. C.
As an article of manufacture, a composite film comprising as a matrix a flexible, coil-like heterocyclic polymer, and embedded in the matrix a reinforcing amount of a rod-like aromatic heterocyclic polymer, the coil-like heterocyclic polymer consisting essentially of repeating units having the following structural formulas:
- ##STR15## , wherein X is NH, N.phi., O or S, where .phi. is phenyl, Ar' is ##STR16## and m is an integer having a value such that the polymer has an intrinsic viscosity of about 2 to 20 dl/g as determined in methanesulfonic acid at 30.degree. C., and the rod-like aromatic heterocyclic polymer consisting essentially of repeating units having the following structural formulas:
- ##STR17## wherein X is NH, N.phi., O or S, where .phi. is phenyl, Ar is ##STR18## and n is an integer having a value such that the polymer has an intrinsic viscosity of about 5 to 30 dl/g as determined in methanesulfonic acid at 30.degree. C.
A method for preparing a composite film which comprises the steps of:
- a. dissolving in methanesulfonic acid solvent a mixture of a flexible, coil-like amorphous heterocyclic polymer and a para ordered, rod-like aromatic heterocyclic polymer, the amount of polymers dissolved being sufficient to provide a 1 to 30 percent solution of the polymer mixture in the solvent and the polymer mixture containing about 5 to 50 weight percent of the rod-like polymer, the coil-like heterocyclic polymer consisting essentially of repeating units having the following structural formulas:
- ##STR23## wherein X is NH, N.phi., O or S, where .phi. is phenyl, Ar' is ##STR24## and m is an integer having a value such that the polymer has an intrinsic viscosity of about 2 to 20 dl/g as determined in methanesulfonic acid at 30.degree. C., and the rod-like aromatic heterocyclic polymer consisting essentially of repeating units having the following structural formulas:
- ##STR25## where X is NH, N.phi., O or S, where .phi. is phenyl, Ar is ##STR26## and n is an integer a value such that the polymer has an intrinsic viscosity of about 5 to 30 dl/g as determined in methanesulfonic acid at 30.degree. C.
- b. introducing the polymer solution into a casting mold;
- c. removing solvent from the polymer solution, thereby forming a composite film in the mold;
- d. recovering the composite film from the mold;
- and
- e. drying the recovered composite film.
Dependencies are inferred from the claim text.