Filter capable of trapping carcinogens and toxic chemicals and manufacturing method thereof

Abstract

A filter has a urethane-based main chain having a repeat unit of the formula, R′—NH—COO—R—O—NH n , wherein the R group and the R′ group are an aliphatic chain and an aromatic group respectively. The R group, R′ group, and —NH— moiety in the repeat unit serve as reactive radicals for trapping cyanides, phenols, or polynuclear aromatic compounds, wherein the reactive radicals are revealed through an extraction process to remove a plurality of contaminants from the urethane-based main chain.

1 . A filter comprising a urethane-based main chain having a repeat unit of the formula,  R′—NH—COO—R—O—NH   n , the R group and the R′ group being an aliphatic chain and an aromatic group respectively, wherein the R group, R′ group, and —NH— moiety in the repeat unit of the urethane-based main chain are reactive radicals for trapping cyanides, phenols, or polynuclear aromatic compounds.  
   
   
       2 . The filter of  claim 1 , wherein the nitrogen atom of the reactive radical —NH— moiety in the repeat unit,  R′—NH—COO—R—O—NH   n , has a lone pair electron for binding the phenols and the cyanides via hydrogen bonds.  
   
   
       3 . The filter of  claim 1 , wherein the reactive radicals R group and R′ group absorb the polynuclear aromatic compounds via van der Waals attraction.  
   
   
       4 . The filter of  claim 1 , wherein the reactive radical R group comprises n-octyl.  
   
   
       5 . The filter of  claim 1 , wherein the reactive radical R′ group comprises tolyl.  
   
   
       6 . The filter of  claim 1 , wherein the reactive radicals are formed through an extraction process to remove a plurality of contaminants originally bonded with the reactive radicals in the repeat unit of the urethane-based main chain.  
   
   
       7 . The filter of  claim 6 , wherein the urethane-based main chain having the contaminants bonded with the reactive radicals in the repeat unit before the extraction process is a polyurethane foam or a polyurethane fiber.  
   
   
       8 . The filter of  claim 7 , wherein the polyurethane foam or polyurethane fiber has a density of between about 0.01 g/ml to about 0.05 g/ml.  
   
   
       9 . The filter of  claim 6 , wherein the reactive radical —NH— moiety is originally occupied by the contaminants comprising phenols before the extraction process.  
   
   
       10 . The filter of  claim 9 , wherein the phenols comprise 6-tert-butyl-2,4-dimethylphenol and butylated methyl phenol.  
   
   
       11 . The filter of  claim 6 , wherein the reactive radicals R group and the R′ group are originally occupied by the contaminants comprising tinuvin, monomers, dimers, oligomers, and 4,4,5,6-tetramethyltetrahydro-1,3-oxazin-2-thione before the extraction process.  
   
   
       12 . The filter of  claim 6 , wherein the extraction is a Soxhlet extraction.  
   
   
       13 . The filter of  claim 12 , wherein the Soxhlet extraction uses a solvent containing 6% ether in hexane to extract the contaminants from the polyurethane material for revealing the urethane-based main chain.  
   
   
       14 . The filter of  claim 12 , wherein the Soxhlet extraction uses a solvent comprising methylene chloride, hexane, light hydrocarbon based solvents, or mixtures of the foregoing to extract the contaminants from the polyurethane material for revealing the urethane-based main chain.  
   
   
       15 . The filter of  claim 6 , wherein the extraction is a supercritical fluid extraction, a steam distillation, a hot solvent extraction, or an organic extraction.  
   
   
       16 . The filter of  claim 6 , the filter is further formed through drying the urethane-based main chain after the extraction process.  
   
   
       17 . The filter of  claim 1 , wherein the polynuclear aromatic compounds comprise 2-methylnaphthalene, acenaphthylene, acenaphthene, dibenzofuran, fluorene, phenanthrene, anthracene, carbazole, fluoranthene, pyrene, benzo(a)anthracene, and chrysene.