Self-lubricating liners free of polyfluoroalkyl substances (pfas)

Abstract

A self-lubricating liner is provided that has a matrix material and an ultra-high molecular weight polyethylene (UHMWPE) lubricant embedded in the matrix material. The matrix material and the lubricant are free of polyfluoroalkyl substances (PFAS) such as, but not limited to, polytetrafluoroethylene (PTFE). In some embodiments, the liner further includes a fabric base embedded in the matrix material.

What is claimed is: 
     
         1 . A self-lubricating liner, comprising:
 a matrix material; and   an ultra-high molecular weight polyethylene (UHMWPE) lubricant embedded in the matrix material, wherein the matrix material and the lubricant are free of polyfluoroalkyl substances (PFAS).   
     
     
         2 . The self-lubricating liner of  claim 1 , further comprising a fabric base and/or reinforcing fibers embedded in the matrix material. 
     
     
         3 . The self-lubricating liner of  claim 1 , further comprising a backing supporting the matrix material having the lubricant embedded therein. 
     
     
         4 . The self-lubricating liner of  claim 1 , wherein the lubricant is present in an amount of 20 to 70 wt. %. 
     
     
         5 . The self-lubricating liner of  claim 1 , wherein the lubricant is present in an amount of 28.5 to 37.5 wt. %. 
     
     
         6 . The self-lubricating liner of  claim 1 , wherein the lubricant is selected from a group consisting of a powder, a floc, loose fibers, whiskers, woven fabrics, non-woven fabrics, felts, and any combinations thereof. 
     
     
         7 . The self-lubricating liner of  claim 1 , wherein the matrix material is selected from a group consisting of polyimide, polyamide, nylon, phenolic, acrylate, allyl-based resin, one-part epoxy, two-part epoxy, crosslinked polyethylene (PEX), polyether ether ketone (PEEK), polyoxymethylene, and combinations thereof. 
     
     
         8 . The self-lubricating liner of  claim 1 , wherein the matrix material and the lubricant are free of a component selected from a group consisting of carbon, carbon-based additives, MoS 2 , and any combinations thereof. 
     
     
         9 . The self-lubricating liner of  claim 1 , wherein the lubricant has a melting temperature below a cure temperature of the matrix material such that the lubricant densifies the matrix material by filling voids and cracks in the matrix material when exposed to the cure temperature. 
     
     
         10 . A self-lubricating liner, comprising:
 a matrix material;   a fabric base embedded in the matrix material; and   an ultra-high molecular weight polyethylene (UHMWPE) lubricant embedded in the matrix material, wherein the matrix material, the fabric base, and the lubricant are free of polyfluoroalkyl substances (PFAS).   
     
     
         11 . The self-lubricating liner of  claim 10 , further comprising a backing supporting the matrix material having the lubricant and fabric base embedded therein. 
     
     
         12 . The self-lubricating liner of  claim 10 , wherein the lubricant is present in an amount of 28.5 to 37.5 wt. %. 
     
     
         13 . The self-lubricating liner of  claim 10 , wherein the lubricant is selected from a group consisting of a powder, a floc, loose fibers, whiskers, woven fabrics, non-woven fabrics, felts, and any combinations thereof. 
     
     
         14 . The self-lubricating liner of  claim 10 , wherein the fabric base is a woven fabric having lubricant fibers comprising the lubricant. 
     
     
         15 . The self-lubricating liner of  claim 14 , wherein the fabric base further comprises reinforcing fibers woven with the lubricant fibers. 
     
     
         16 . The self-lubricating liner of  claim 14 , wherein the woven fabric has a weave selected from a group consisting of square, twill, satin, plain, basket, non-woven, felted, randomly oriented, and any combinations thereof. 
     
     
         17 . The self-lubricating liner of  claim 10 , wherein the matrix material is selected from a group consisting of polyimide, polyamide, nylon, phenolic, acrylate, allyl-based resin, one-part epoxy, two-part epoxy, crosslinked polyethylene (PEX), polyether ether ketone (PEEK), polyoxymethylene, and combinations thereof. 
     
     
         18 . The self-lubricating liner of  claim 10 , wherein the matrix material, fabric base, and the lubricant are free of a component selected from a group consisting of carbon, carbon-based additives, MoS 2 , and any combinations thereof. 
     
     
         19 . The self-lubricating liner of  claim 10 , wherein the lubricant has a melting temperature below a cure temperature of the matrix material such that the lubricant densifies the matrix material by filling voids and cracks in the matrix material when exposed to the cure temperature. 
     
     
         20 . A self-lubricating liner, comprising:
 a matrix material that comprises phenolic or epoxy; and   an ultra-high molecular weight polyethylene (UHMWPE) lubricant embedded in the matrix material, the lubricant being present in an amount of 28.5 to 37.5 wt. %,   wherein the matrix material and the lubricant are free of polyfluoroalkyl substances (PFAS).   
     
     
         21 . The self-lubricating liner of  claim 20 , wherein the lubricant has a melting temperature below a cure temperature of the matrix material such that the lubricant densifies the matrix material by filling voids and cracks in the matrix material when exposed to the cure temperature. 
     
     
         22 . The self-lubricating liner of  claim 20 , wherein the matrix material further comprises an additive selected from a group consisting of metal sulfide additives, metal oxide additives, nitride additives, carbon additives, MoS 2 , WS 2 , ZnS, TiO 2 , ZnO, ZrO 2 , nitride additives, hexagonal boron nitride (h-BN), silicon nitride (Si 3 N 4 ), carbon fiber, graphite, graphene, carbon nanotubes, fluorinated carbon additives, non-fluorinated carbon additives, and combinations thereof. 
     
     
         23 . The self-lubricating liner of  claim 20 , wherein the lubricant is present in an amount of 33.33 wt. % and has a melting temperature below a cure temperature of the matrix material such that the lubricant densifies the matrix material by filling voids and cracks in the matrix material when exposed to the cure temperature, and
 wherein the matrix material comprises hexagonal boron nitride (h-BN) and/or silicon nitride (Si 3 N 4 ) in an amount of between 2-8 wt. % with respect to the matrix material.   
     
     
         24 . The self-lubricating liner of  claim 23 , wherein the amount of hexagonal boron nitride (h-BN) and/or silicon nitride (Si 3 N 4 ) is between 2.25-3.5 wt. % with respect to the matrix material.