Anti-Extrusion Compositions for Sealing and Wear Components

Abstract

A method and compositions are described which improve extrusion- and creep-resistance of components for use in a high temperature applications including sealing elements and seal connectors among others. The method includes providing a composition having an aromatic polymer and a crosslinking compound, and subjecting the composition to a heat molding process to form the component and crosslink the aromatic polymer.

We claim: 
     
         1 . A composition for formation of an extrusion-resistant sealing member, comprising:
 a polymer selected from the group consisting of a polyarylene polymer, a polysulfone, a polyphenylenesulfide, a polyimide, a polyamide, a polyurea, a polyurethane, a polyphthalamide, a polyamide-imide, an aramid, a polybenzimidazole, and blends, copolymers and derivatives thereof.   a crosslinking compound, wherein the crosslinking compound has a structure according to formula (II):   
       
         
           
           
               
               
           
         
       
       wherein A is an arene moiety having a molecular weight of less than 10,000 g/mol, R 1  is selected from a group consisting of hydroxide (—OH), amine (—NH 2 ), halide, ether, ester or amide, and x=2.0 to 6.0. 
     
     
         2 . The composition of  claim 1 , wherein the polymer is a polyarylene polymer, a polysulfone polymer, or a blend, a copolymer, or a derivative thereof. 
     
     
         3 . The composition of  claim 2 , wherein the polyarylene polymer is one or more of a polyetheretherketone (PEEK), a polyetherketone (PEK), a polyetherketoneetherketoneketone (PEKEKK), a polyetherketoneketone (PEKK), a polysulfone (PSU), a polyethersulfone (PES), a polyarylsulfone (PAS), and blends, copolymers and derivatives thereof. 
     
     
         4 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches produces a static extrusion height of no greater than 0.11 mm when tested at 290° C. under a pressure of 35,000 psi in a load cell having a 0.51 mm extrusion gap. 
     
     
         5 . The composition of  claim 4 , wherein the extrusion height after one hour is no greater than 0.21 mm. 
     
     
         6 . The composition of  claim 5 , wherein the extrusion height after three hours is no greater than 0.24 mm. 
     
     
         7 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches has a tensile modulus at 200° C. of at least 0.99 GPa as measured in accordance with ASTM D638. 
     
     
         8 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches has a post-yield tensile strength at 200° C. and at 10% strain of at least 43.2 GPa as measured in accordance with ASTM D638. 
     
     
         9 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches has a compressive strength at 200° C. of at least 121.9 MPa as measured in accordance with ASTM D690. 
     
     
         10 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches and when tested according to ASTM D2990 at 260° C. with a stress of 10 MPa has an instant creep modulus of at least 4.95 MPa. 
     
     
         11 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches and when tested according to ASTM D2990 at 260° C. with a stress of 10 MPa has a creep modulus at 1 hour of at least 4.31 MPa. 
     
     
         12 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches and when tested according to ASTM D2990 at 260° C. with a stress of 10 MPa has a creep modulus at 3 hours of at least 4.26 MPa. 
     
     
         13 . The composition of  claim 1 , wherein the composition when formed into a molded article having a cylindrical configuration with a diameter of 0.5 inches and a thickness of 0.12 inches and when tested according to ASTM D2990 at 260° C. with a stress of 10 MPa has a creep modulus at 7.5 hours of at least 4.12 MPa.