Superhydrophilic amphiphilic copolymers and processes for making the same

Abstract

A superhydrophilic amphiphilic copolymer and process for making the superhydrophilic amphiphilic copolymer includes a low molecular weight polysaccharide modified with a hydrophobic reagent, such as substituted succinic anhydride. The superhydrophilic amphiphilic copolymer system generates stable foam for use in applications, such as healthcare formulations, with low irritation of the eyes and skin.

What is claimed is: 
     
         1 . A superhydrophilic amphiphilic copolymer comprising a starch-based polysaccharide derived from potato or tapioca modified with dodecenyl succinic anhydride wherein the superhydrophilic amphiphilic copolymer has a weight average molecular weight that is less than about 200,000, and wherein a 2% aqueous solution of the superhydrophilic amphiphilic copolymer at 25° C. has a solution viscosity of 9 centipoise or less. 
     
     
         2 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the polysaccharide has a degree of polymerization of between 4 and 200 repeat units. 
     
     
         3 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the weight average molecular weight of the polysaccharide is from about 1,000 to about 25,000. 
     
     
         4 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the dodecenyl succinic anhydride is linear or branched. 
     
     
         5 . The superhydrophilic amphiphilic copolymer of  claim 4  wherein the branched dodecenyl succinic anhydride is tetrapropenyl succinic anhydride. 
     
     
         6 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the polysaccharide has a bound dodecenyl succinic anhydride of from about 3 to about 15 percent based on the dry weight of the polysaccharide. 
     
     
         7 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the superhydrophilic amphiphilic copolymer has a turbidity of less than about 120 ntu of a 10% aqueous solution. 
     
     
         8 . The superhydrophilic amphiphilic copolymer of  claim 7  wherein the turbidity is less than about 10 ntu of a 10% aqueous solution. 
     
     
         9 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the superhydrophilic amphiphilic copolymer forms a Max Foam Volume of about 400 mLs or greater when 1000 mls of a 0.5% aqueous solution of the polymeric surfactant is stirred at 1200 RPMs for 150 seconds. 
     
     
         10 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the Foam Stability is about 40% or greater. 
     
     
         11 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the weight average molecular weight of the polysaccharide is from about 1,000 to about 15,000. 
     
     
         12 . The superhydrophilic amphiphilic copolymer of  claim 1  wherein the superhydrophilic amphiphilic copolymer has a mole percent of amphiphilic units that is from 5 to 7.7. 
     
     
         13 . A process for making a superhydrophilic amphiphilic copolymer comprising:
 dissolving a starch-based polysaccharide derived from potato or tapioca in water to form an aqueous solution;   adjusting the pH of the aqueous solution;   reacting dodecenyl succinic anhydride with the polysaccharide in the aqueous solution;   cooling the resulting copolymer solution; and   neutralizing the copolymer solution,   
       wherein the superhydrophilic amphiphilic copolymer has a weight average molecular weight that is less than about 200,000, and wherein a 2% aqueous solution of the superhydrophilic amphiphilic copolymer at 25° C. has a solution viscosity of 9 centipoise or less. 
     
     
         14 . A process for making a dry superhydrophilic amphiphilic copolymer comprising the process of  claim 13  and further comprising removing the water from the copolymer solution. 
     
     
         15 . The process of  claim 13  wherein the polysaccharide has a weight average molecular weight of from about 1,000 to about 100,000. 
     
     
         16 . The process of  claim 13  wherein the dodecenyl succinic anhydride is linear or branched. 
     
     
         17 . The process of  claim 16  wherein the branched dodecenyl succinic anhydride is tetrapropenyl succinic anhydride. 
     
     
         18 . The process of  claim 13  wherein the superhydrophilic amphiphilic copolymer has a mole percent of amphiphilic units that is from 5 to 7.7.