Reduced vapor pressure gelled fuels and solvents

Abstract

The present invention relates generally to gelled fuels and solvents. Specifically the invention relates to gel thickeners that reduce vapor pressure in fuels and solvents and are shear thinning (pseudoplastic or thixotropic) or are shear thickening and remain pourable and flowable. Still more specifically, the invention relates to nonaqueous gels made with diblock copolymers that reduce the Reid Vapor Pressure of gelled gasoline and lower the total volatility of gelled hydrocarbon solvents. These gels may contain secondary amino acid or triblock polymer gelling agents. The invention includes gel compositions and methods of making gels.

1 . A method for reducing the vapor pressure a liquid hydrocarbon comprising adding an effective amount of diblock copolymer to the liquid hydrocarbon to form a shear thinning hydrocarbon gel having a vapor pressure lower than the vapor pressure of said liquid hydrocarbon. 
     
     
         2 . The method of  claim 1 , wherein the diblock copolymer has a molecular weight of from 100,000 to 500,000 and the effective amount of diblock copolymer added to the liquid hydrocarbon is from about 0.5 to about 20 weight percent. 
     
     
         3 . The method of  claim 2 , wherein the liquid hydrocarbon is an aliphatic solvent that is composed primarily of C 13 -C 20  isoparaffinic and cycloparaffinic hydrocarbons. 
     
     
         4 . The method of  claim 3 , including adding 0.1 to 3.0 weight percent of a triblock copolymer gelling agent to the liquid hydrocarbon. 
     
     
         5 . The method of  claim 3 , including adding 0.1 to 3.0 weight percent of an amino acid gelling agent to the liquid hydrocarbon. 
     
     
         6 . The method of  claim 3 , wherein the liquid hydrocarbon is a petroleum fuel. 
     
     
         7 . The method of  claim 6 , wherein the petroleum fuel is gasoline and the effective amount of diblock copolymer is from 5 to 15 weight percent, 
     
     
         8 . The method of  claim 7 , wherein the gasoline contains additives selected from the group consisting of: oxygenates, corrosion inhibitors, chelating agents, emulsifiers, antiknock compounds, surfactants, alcohols, dyes and markers.