Systems and Methods for Making Hydrophilic Foams

Abstract

Provided herein are methods for making foam materials and foam material products having a polyurethane foam matrix defining a plurality of pores, a hydrophilic agent retained within at least a portion of the pores for improving an absorption of the foam material, a salt retained within at least a portion of the pores in an amount sufficient to render the foam material isotonic, a surfactant retained within at least a portion of the pores in an amount sufficient to be released upon contact with a moist surface. Also provided herein are methods for making a multilayer foam by casting a second foam layer on a first foam layer substrate and compressing the second foam layer before the second layer is fully cured to form an interface layer in situ.

1 - 139 . (canceled) 
     
     
         140 . A method of producing a foam, comprising:
 producing a foam slurry, the foam slurry comprising:
 a hydrophilic agent for improving an absorption property of liquid of the foam to retain the liquid within the foam; 
 a salt in an amount sufficient to render a layer of foam isotonic; 
 water; and 
 a surfactant in an amount sufficient to be released upon contact between the layer of foam and a moist surface; 
   mixing the foam slurry with a water reactive prepolymer to form a foam reaction product; and   forming a foam layer from the foam reaction product.   
     
     
         141 . The method of  claim 140 , wherein forming the foam layer comprises:
 depositing the foam reaction product on a substrate;   allowing the foam reaction product to rise; and   compressing the foam reaction product to a desired thickness.   
     
     
         142 . The method of  claim 141 , wherein forming the foam layer further comprises:
 allowing the foam reaction product, after compressing, to rise to provide a porous cellular foam sheet of a predetermined thickness;   compressing the foam after rising for uniform thickness; and   curing the foam sheet.   
     
     
         143 . The method of  claim 140 , wherein the hydrophilic agent is 1 to 20% by weight of the foam layer, the salt retained is 0.1 to 5% by weight of the foam layer, the surfactant is 5 to 9% by weight of the foam layer, and the water is 8 to 12% by weight of the foam layer. 
     
     
         144 . The method of  claim 140 , wherein the salt is one of sodium chloride, calcium chloride, potassium chloride, magnesium chloride, saline solutions, Ringers Solution, Tyrodes solution, or combinations thereof. 
     
     
         145 . The method of  claim 140 , wherein the hydrophilic agent is a superabsorbent polymer. 
     
     
         146 . The method of  claim 140 , wherein forming the foam layer can include casting or extruding the foam slurry. 
     
     
         147 . A method of producing a foam, comprising:
 producing a first layer of foam material;   producing one or more secondary layers of foam material; and   producing one or more interface layers for bonding at least one of the first layer of foam material and one of the one or more secondary layers of foam material or bonding adjacent the one or more secondary layers of foam material, the one or more interface layers being interposed between the first layer and the one or more secondary layers for controlling a moisture vapor transmission rate through the one or more interface layers.   
     
     
         148 . The method of  claim 147 , wherein each of the one or more interface layers includes compressed or collapsed polyurethane foam matrix from at least one of the first layer of foam material or the one or more secondary layers of foam material. 
     
     
         149 . The method of  claim 147 , wherein the first layer comprises:
 a first polyurethane foam matrix defining a plurality of first pores;   a first hydrophilic agent retained within at least a portion of the plurality of first pores for improving an absorption property of the foam material;   a first salt retained within at least a portion of the plurality of first pores in an amount sufficient to render the first layer of foam isotonic; and   a first surfactant retained within at least a portion of the plurality of first pores in an amount sufficient to be released upon contact between the first layer of foam material and a moist surface.   
     
     
         150 . The method of  claim 147 , wherein each of the one or more secondary layers comprises:
 a secondary polyurethane foam matrix defining a plurality of secondary pores;   a secondary hydrophilic agent retained within at least a portion of the plurality of secondary pores for improving an absorption property of the foam material;   a secondary salt retained within at least a portion of the plurality of secondary pores in an amount sufficient to render the one or more secondary layers of foam material isotonic; and   a secondary surfactant retained within at least a portion of the plurality of secondary pores in an amount sufficient to be released upon contact between the one or more secondary layers of foam material and a moist surface.   
     
     
         151 . The method of  claim 147 , wherein a moisture vapor transmission rate (MVTR) of the foam is determined by an MVTR of the one or more interface layers. 
     
     
         152 . The method of  claim 149 , wherein the first layer includes one or more of an adjuvant, a colorant, a pH indicator, an antimicrobial, a medicament, a skin softener, or combinations thereof retained within at least a portion of the plurality of first pores. 
     
     
         153 . The method of  claim 150 , wherein at least one of the one or more secondary layers includes one or more of an adjuvant, a colorant, a pH indicator, an antimicrobial, a medicament, a skin softener, or combinations thereof retained within at least a portion of the plurality of secondary pores. 
     
     
         154 . The method of  claim 149 , wherein the first hydrophilic agent is 1 to 20% by weight of the first layer, the first salt retained is 0.1 to 5% by weight of the first layer, and the first surfactant is 5 to 9% by weight of the first layer. 
     
     
         155 . The method of  claim 150 , wherein the secondary hydrophilic agent is 1 to 20% by weight of each of the one or more secondary layers, the secondary salt retained is 0.1 to 5% by weight of each of the one or more secondary layers, and the secondary surfactant is 5 to 9% by weight of each of the one or more secondary layers.