Method for improving the mechanical properties of soil, a polymeric solution therefore, and a process for preparing polymeric solutions
AssigneeKuwait Institute for Scientific Research
InventorsShawqui Lahalih, Ma'mun Absi-Halabi, Nouria Al-Awadhi, Khamis Shuhaibar
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method for improving the mechanical properties of soil. The method uses an aqueous solution of a sulfonated urea melamine formaldehyde resin and a water soluble polyvinyl alcohol having a molecular weight between 40,000 and 120,000. The aqueous solution is sprayed onto the surface of the soil. A number of water soluble compositions which include a sulfonated urea melamine formaldehyde resin and polyvinyl alcohol and methods for making the same are also disclosed.
Claims26
A process for preparing a polymeric solution for use as a soil stabilizer comprising the steps of:
- (a) mixing an aqueous formaldehyde solution having a concentration ranging between about 30-50% at a temperature of between about 40.degree. to 60.degree. C. and a pH of about 10 to 12 with a urea-melamine resin so that the molar ratio of formaldehyde to urea-melamine is in the range of 2.5 to 4.5:1 until the urea-melamine resin dissolves;
- (b) adding a sulfonating agent in an amount to provide a molar ratio of sulfite group to the urea-melamine in the range of 0.8 to 1.2:1 and heating the resulting solution to a temperature of about 70.degree. to 90.degree. C. for a period of 20 to 100 minutes;
- (c) cooling the solution to about 40.degree.-60.degree. C. and adjusting the pH of the solution to about 2.5 to 4.0 and polymerizing the reactants in the solution for a period of 30 to 150 minutes;
- (d) adjusting the pH of the solution to about 7-9, heating the solution to a temperature of between 70.degree.-90.degree. C. and adding polyvinyl alcohol having an average molecular weight in the range of 40,000 to 120,000 to the solution until the weight ratio of the polyvinyl alcohol to sulfite groups is between 0.001 to 0.03, and maintaining the reaction solution at the 70.degree. to 90.degree. C. temperature for between 30 and 150 minutes.
A water soluble polymeric composition for use as a soil stabilizer comprising a sulfonated urea-melamine formaldehyde resin having a relative average molecular weight of between about 700,000 and 1,000,000, a polyvinyl alcohol having an average molecular weight within the range of 40,000 to 120,000 wherein the weight ratio of the urea-melamine resin to the polyvinyl alcohol ranges from 100:1 to 200:1 and water with the concentration of solids within the solution within the range of 5% to 50%.
A method for improving the mechanical properties of soil and its resistance to erosion comprising the steps of:
- (a) providing a water soluble polymeric composition containing a sulfonated urea-melamine formaldehyde resin having a relative average molecular weight of between about 700,000 and 1,000,000, a polyvinyl alcohol having an average molecular weight within tha range of 40,000 to 120,000 wherein the weight ratio of the urea-melamine resin to the polyvinyl alcohol ranges from 100:1 to 200:1, and water with the concentration of solids within the solution within the range of 5% to 50%;
- and,
- (b) spraying the water soluble solutions on to the surface of the soil which is to be stabilized.
A method for improving the mechanical properties of soil and its resistance to erosion comprising the steps of:
- (a) mixing an aqueous formaldehyde solution having a concentration ranging between about 30-50% at a temperature of between about 40.degree. to 60.degree. C. and a pH of about 10 to 12 with a urea-melamine resin so that the molar ratio of formaldehyde to urea-melamine is in the range of 2.5 to 4.5:1 until the urea-melamine resin dissolves;
- (b) adding a sulfonating agent in an amount to provide a molar ratio of sulfite group to the urea-melamine in the range of 0.8 to 1.2:1 and heating the resulting solution to a temperature of about 70.degree. to 90.degree. C. for a period of 20 to 100 minutes;
- (c) cooling the solution to about 40.degree.-60.degree. C. and adjusting the pH of the solution to about 2.5 to 4.0 and polymerizing the reactants in the solution for a period of 30 to 150 minutes;
- (d) adjusting the pH of the solution to about 7-9, heating the solution to a temperature of between 70.degree.-90.degree. C. and adding polyvinyl alcohol having an average molecular weight in the range of 40,000 to 120,000 to the solution until the weight ratio of the polyvinyl alcohol to sulfite groups is between 0.001 to 0.03, and maintaining the reaction solution at the 70.degree. to 90.degree. C. temperature for between 30 and 150 minutes;
- (e) cooling the solution containing polyvinyl alcohol and diluting the solution with water until the final solids content is about 5-15%;
- and,
- (f) spraying the diluted solution onto the surface of the soil which is to be treated.
Dependencies are inferred from the claim text.