Boron reinforced polyimide composites

Abstract

Abstract THIS INVENTION IS DIRECTED TO A PROCESS FOR PREPARING REINFORCED RESIN LAMINATES AND THE PRODUCTS OBTAINED THEREFROM CHARACTERIZED AS HAVING IMPROVED THERMAL STABILITY AND LOW-VOID CONTENT. MORE SPECIFICALLY THIS INVENTION IS DIRECTED TO A PROCESS OF PREPARING REINORCED POLYIMIDE LAMINATES OR PLASTIC COMPOSITES WHICH COMPRISES IMPREGNATING A SUBSTANTIALLY FIBROUS MATERIAL, I.E., BORON FILAMENTS WITH AN EFFECTIVE AMOUT OF AN ORGANIC SOLUTION OF A POLYAMIDE-ACID PRECURSOR. THE BORON FILAMENTS IMPREGNATED WITH THE PRECURSOR, I.E., THE POLYAMIDE-ACID, MAY BE HEATED TO TEMPERATURES RANGING UP TO ABOUT 125* C. TO REMOVE A SUBSTANTIAL PART OF THE SOLVENT AND THEREBY OBTAIN AN INTERMEDIATE WHICH MAY BE CHARACTERIZED AS HAVING TACK AND DRAPE. SUBSEQUENTLY, THE POLYAMIDE-ACID MAY BE IMIDIZED, IN SITU, TO THE IMIDE PREPOLYMER AND THEN CURED OR ALTERNATIVELY CURED DIRECTLY BY THE APPLICATION OF HEAT WITH TEMPERATURES RANGING FROM ABOUT 125* C. TO 350* C. AND AT PRESSURES RANGING UP TO ABOUT 1200 P.S.I. UNDER THESE CONDITIONS, THE POLYAMIDE-ACID WILL BE CURED, IN SITU, TO FORM A REINFORCED THERMOSETTING RESIN LAMINATE OR COMPOSITE. THE PRECURSOR OF THE POLYIMIDE PREPOLYMER, I.E., THE POLYAMIDE-ACID, MAY BE PREPARED BY COREACTING APPROXIMATELY STOICHIOMETRIC AMOUNTS OF AT LEAST ONE POLYFUNCTIONAL AMINE WITH A MIXTURE OF ANHYDRIDES CONSISTING ESSENTIALLY OF AT LEAST ONE POLYFUNCTIONAL ANHYDRIDE AND A MONOANHYDRIDE HAVING THE FORMULA: 1,3-DI(O=),3A,7A-DI(R-),R-1,3,3A,4,7,7A-HEXAHYDRO- 4,7-METHANOISOBENZOFURAN WHEREIN R IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND LOWER ALKYL RADICALS HAVING 1 TO 5 CARBON ATOMS PER MOLECULE AND COMBINATIONS THEREOF.

Inventors

• 👤 Hyman R Lubowitz
• 👤 Robert W Vaughan

Bibliographic Details