Membranes and uses thereof

Abstract

Membranes and methods for producing them are disclosed. The membranes comprise a core layer comprising a composite of alternating thermoplastic polyurethane (TPU) and barrier microlayers, and they comprise at least one cap layer that is bonded to the core layer or a structural layer. In some embodiments, at least the cap layer comprises a polydiene polyol-based TPU. The membrane may further comprise a rubber layer bonded to the cap layer.

1 .- 12 . (canceled) 
     
     
         13 . A method for producing a membrane, comprising:
 (a) co-extruding alternating barrier microlayers and TPU microlayers to form a core layer comprising a composite of the barrier and TPU microlayers; and   (b) either co-extruding at least one cap layer with the core layer or laminating at least one cap layer onto the core layer.   
     
     
         14 . The method of  claim 13 , wherein the at least one cap layer is a TPU cap layer. 
     
     
         15 . The method of  claim 13 , wherein the at least one cap layer is a reactive cap layer. 
     
     
         16 . The method of  claim 13 , wherein the membrane has a gas transmission rate for nitrogen gas of from about 0.001 cm 3 /m 2 ·atm·day to about 1 cm 3 /m 2 ·atm·day. 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 13 , further comprising incorporating the membrane into a shoe, skate, ball, tire, bicycle seat, saddle, personal protective article, flexible flotation device, rigid flotation device, medical device, prosthetic device, orthopedic device, accumulator, or article of furniture. 
     
     
         19 . The method of  claim 13 , further comprising inflating and sealing the membrane to form a gas-filled bladder, cushioning device, impact arrestor, or substantially closed container. 
     
     
         20 . The method of  claim 19 , further comprising incorporating the gas-filled bladder, cushioning device, impact arrestor, or substantially closed container into a shoe, skate, ball, tire, bicycle seat, saddle, personal protective article, flexible flotation device, rigid flotation device, medical device, prosthetic device, orthopedic device, accumulator, or article of furniture. 
     
     
         21 . The method of  claim 13 , further comprising using a tie layer to bond the core layer to the at least one cap layer. 
     
     
         22 . The method of  claim 13 , further comprising applying at least one TPU structural layer to the core layer to give a combination core-and-structural layer. 
     
     
         23 . The method of  claim 22 , further comprising co-extruding the at least one cap layer with the combination core-and-structural layer to form the membrane. 
     
     
         24 . The method of  claim 22 , further comprising laminating the at least one cap layer onto the combination core-and-structural layer to form the membrane. 
     
     
         25 . The method of  claim 22 , further comprising at least one of: (a) using a tie layer to bond the core layer to the at least one structural layer; and (b) using a tie layer to bond the combination core-and-structural layer to the at least one cap layer. 
     
     
         26 . The method of  claim 13 , further comprising the step of bonding a rubber layer to the at least one cap layer. 
     
     
         27 . The method of  claim 26 , wherein the rubber layer comprises a natural rubber, a butyl rubber, a neoprene rubber, a nitrile rubber, an isoprene rubber, a butadiene rubber, a styrene-butadiene rubber, an ethylene-propylene-diene rubber, an ethylene-propylene rubber, a urethane rubber, or any combination thereof. 
     
     
         28 . The method of  claim 14 , wherein the at least one cap layer comprises a first polydiene polyol-based TPU. 
     
     
         29 . The method of  claim 28 , wherein the polydiene polyol-based TPU comprises a polybutadiene polyol, a polyisoprene polyol, or both. 
     
     
         30 . The method of  claim 19 , wherein the gas-filled bladder, cushioning device, impact arrestor, or substantially closed container has a moisture content within the range of 1 to 50 parts per million when equilibrated for 24 hours at 30 degrees Celsius with a relative humidity of 50 percent. 
     
     
         31 . The method of  claim 13 , wherein the barrier microlayers of the core layer comprise an ethylene-vinyl alcohol copolymer. 
     
     
         32 . The method of  claim 13 , wherein the at least one cap layer comprises a cure package. 
     
     
         33 . The method of  claim 33 , wherein the cure package comprises molecular sulfur or peroxide curing agents.