Porogen compositions, methods of making and uses

Abstract

Provided are porogen compositions and methods of using such porogen compositions in the manufacture of porous materials, for example, porous silicone elastomers. The porogens generally include comprising a core material and shell material different from the core material. The porogens can be used to form a scaffold for making a resulting porous elastomer when the scaffold is removed.

What is claimed is: 
     
         1 . A porogen composition usefulo forma scaffold for making a porous material, the composition comprising:
 a) a shell material; and   b) a core material;
 wherein under a given physical or physicochemical treatment the shell material is fusible and the core material is non-fusible. 
   
     
     
         2 . The porogen composition of  claim 1 , wherein the shell fusion occurs by a physical state change from solid phase to liquid or rubbery phase. 
     
     
         3 . The porogen composition of  claim 1 , wherein the physicochemical treatment is heat treatment. 
     
     
         4 . The porogen composition of  claim 1 , wherein the physicochemical treatment is contact of the composition with an organic solvent. 
     
     
         5 . The porogen composition of  claim 1 , wherein the shell material is a salt and its derivatives, a ceramic and/or its derivatives, a sugar and its derivatives, a polysaccharide and its derivatives, a wax and its derivatives, a metal and its derivatives, a surfactant and its derivatives, a water soluble solid and its derivatives, a polymer and its derivatives, composites thereof, or combinations thereof. 
     
     
         6 . The porogen composition of  claim 1 , wherein the core material is a salt and its derivatives, a ceramic and/or its derivatives, a sugar and its derivatives, a polysaccharide and its derivatives, a wax and its derivatives, a metal and its derivatives, a water soluble solid and its derivatives, a polymer and its derivatives, composites thereof, or combinations thereof. 
     
     
         7 . The porogen composition of  claim 1 , wherein the core material is a sugar and the shell material is polyethylene glycol. 
     
     
         8 . A method of making a porogen composition useful to form a scaffold for making a porous material, the method comprising the steps of:
 a) forming a particle out of a core material; and   b) coating the particle with a shell material;
 wherein the porogen composition comprises a shell material and a core material, wherein the shell material has a melting temperature that is lower than a melting temperature of the core material. 
   
     
     
         9 . The method of  claim 8 , wherein the shell material is a salt and its derivatives, a ceramic and/or its derivatives, a sugar and its derivatives, a polysaccharide and its derivatives, a wax and its derivatives; a metal and its derivatives; a surfactant and its derivatives, a water soluble solid and its derivatives, a polymer and its derivatives, composites thereof, or combinations thereof. 
     
     
         10 . The method of  claim 8 , wherein the core material is a salt and its derivatives, a ceramic and/or its derivatives, a sugar and its derivatives, a polysaccharide and its derivatives, a wax and its derivatives, a metal and its derivatives, a water soluble solid and its derivatives, a polymer and its derivatives, composites thereof, or combinations thereof. 
     
     
         11 . The method of  claim 8 , wherein the core material is a sugar and the shell material is polyethylene glycol. 
     
     
         12 . An article of manufacture comprising;
 an elastomeric porous material made by the method of:
 a) coating porogens with a matrix material to form a matrix material-coated porogen mixture, the porogens comprise a shell material and a core material, wherein the shell material has a melting temperature that is lower than a melting temperature of the core material; 
   
     
     
         13 . The article of  claim 12 , wherein the matrix material is a silicone dispersion.