Low Molecular Weight Graft Copolymers

Abstract

Low molecular weight graft copolymer comprising a synthetic component formed from at least one or more olefinically unsaturated carboxylic acid monomers or salts thereof, and a natural component formed from a hydroxyl-containing natural moiety. The number average molecular weight of the graft copolymer is about 100,000 or less, and the weight percent of the natural component in the graft copolymer is about 50 wt % or greater based on total weight of the graft copolymer. Processes for preparing such graft copolymers are also disclosed.

1 . Low molecular weight graft copolymer comprising:
 a synthetic component formed from at least one or more olefinically unsaturated carboxylic acid monomers or salts thereof, and   a natural component formed from a hydroxyl-containing natural moiety,   wherein the number average molecular weight of the graft copolymer is about 100,000 or less, and   wherein the weight percent of the natural component in the graft copolymer is about 5 wt % or greater based on total weight of the graft copolymer.   
   
   
       2 . Graft copolymer according to  claim 1  wherein the synthetic component is further formed from one or more monomers having a nonionic, hydrophobic and/or sulfonic acid group,
 wherein the one or more monomers are incorporated into the copolymer in an amount of about 50 weight percent or less based on total weight of the graft copolymer.   
   
   
       3 . Graft copolymer according to  claim 2  wherein the one or more monomers are incorporated into the copolymer in an amount of about 10 weight percent or less based on total weight of the graft copolymer. 
   
   
       4 . Graft copolymer according to  claim 1  wherein the hydroxyl-containing natural moiety is water soluble. 
   
   
       5 . Graft copolymer according to  claim 1  wherein the hydroxyl-containing natural moiety is degraded. 
   
   
       6 . Graft copolymer according to  claim 1  wherein the carboxylic acid monomer is selected from the group consisting of acrylic acid, maleic acid, methacrylic acid and mixtures thereof. 
   
   
       7 . Graft copolymer according to  claim 5  wherein the carboxylic acid monomer is acrylic acid. 
   
   
       8 . Graft copolymer according to  claim 5  wherein the carboxylic acid monomer is acrylic acid and maleic acid. 
   
   
       9 . Graft copolymer according to  claim 1  wherein the weight percent of the natural component in the graft copolymer is about 50 wt % or greater based on total weight of the graft copolymer. 
   
   
       10 . Graft copolymer according to  claim 1  wherein the natural component is selected from the group consisting of glycerol, citric acid, maltodextrins, pyrodextrins, corn syrups, maltose, sucrose, low molecular weight oxidized starches and mixtures thereof. 
   
   
       11 . Cleaning composition comprising the graft copolymer according to  claim 1 , wherein the copolymer is present in the cleaning composition in an amount of from about 0.01 to about 10 weight %. 
   
   
       12 . Cleaning composition comprising the graft copolymer according to  claim 1 , wherein the cleaning composition further comprises one or more adjuvants. 
   
   
       13 . Cleaning composition comprising the graft copolymer according to  claim 12 , wherein the cleaning composition is a detergent composition, and wherein the graft copolymer has a Gardner color of about 12 or less. 
   
   
       14 . Cleaning composition comprising the graft copolymer according to  claim 13 , wherein the detergent composition is a powdered detergent or unit dose composition. 
   
   
       15 . Cleaning composition comprising the graft copolymer according to  claim 13 , wherein the detergent composition is an autodish composition. 
   
   
       16 . Cleaning composition comprising the graft copolymer according to  claim 13 , wherein the detergent composition is a zero phosphate composition. 
   
   
       17 . Method of reducing spotting and/or filming in the rinse cycle of an automatic dishwasher comprising adding to the rinse cycle a rinse aid composition comprising the graft copolymer according to  claim 1   
   
   
       18 . Method of improving sequestration, threshold inhibition and soil removal in a cleaning composition comprising adding the graft copolymer according to  claim 1  to the cleaning composition. 
   
   
       19 . Water treatment system comprising the graft copolymer according to  claim 1 , wherein the graft copolymer is present in the system in an amount of at least about 0.5 mg/L. 
   
   
       20 . Method of dispersing and/or minimizing scale in an aqueous system comprising adding the graft copolymer according to  claim 1  to a water treatment system. 
   
   
       21 . Method of dispersing pigments and/or minerals in an aqueous system comprising adding a dispersant composition comprising the graft copolymer according to  claim 1  to the aqueous system. 
   
   
       22 . Dispersant composition comprising the graft copolymer according to  claim 20 , wherein the minerals dispersed comprise titanium dioxide, kaolin clays, modified kaolin clays, calcium carbonates and synthetic calcium carbonates, iron oxides, carbon black, talc, mica, silica, silicates, aluminum oxide or mixtures thereof. 
   
   
       23 . Method of dispersing soils and/or dirt from hard and/or soft surfaces comprising treating the hard and/or soft surfaces with a cleaning composition comprising the graft copolymer according to  claim 1 . 
   
   
       24 . Method of dispersing soils and/or dirt in aqueous systems comprising treating the aqueous system with an aqueous treatment composition comprising the graft copolymer according to  claim 1 . 
   
   
       25 . Process for producing low molecular weight graft copolymers having a synthetic component and a natural component, the process comprising:
 degrading the natural component to a number average molecular weight of about 100,000 or less,   reacting the natural component with a free radical initiating system having a metal ion to generate free radicals on the natural component, and   polymerizing the free radical-containing natural component with a synthetic component,   wherein the low molecular weight graft copolymer has a Gardner color of about 12 or less.   
   
   
       26 . Process according to  claim 25  further comprising polymerizing the free radical-containing natural component with the synthetic component at ambient pressure and a reaction temperature of about 40° C. to about 130° C. 
   
   
       27 . Process according to  claim 25  wherein the metal ion is a Cu (II) salt. 
   
   
       28 . Process according to  claim 25  wherein polymerization occurs at a pH of about 6 or less. 
   
   
       29 . A graft copolymer comprising:
 a synthetic component formed from at least one or more olefinically unsaturated carboxylic acid monomers or salts thereof, and   a natural component formed from a hydroxyl-containing natural moiety,   wherein the weight percent of the natural component in the graft copolymer is about 5 wt % or greater based on total weight of the graft copolymer.   
   
   
       30 . A cement composition for use in oil field systems comprising the graft copolymer of  claim 1 , cement, and water. 
   
   
       31 . A drilling fluid composition for use in oil field systems comprising the graft copolymer of  claim 1 , drilling mud and water. 
   
   
       32 . A spacer composition for use in oil field systems comprising the graft copolymer of  claim 1 , at least one surfactant and water. 
   
   
       33 . The spacer fluid composition of  claim 4  further comprising viscosifiers and weighting materials. 
   
   
       34 . A scale inhibition composition for use in water treatment and oil field systems comprising the graft copolymer of  claim 1 , wherein the number average molecular weight of the graft copolymer is about 100,000 or less. 
   
   
       35 . The scale inhibition composition of  claim 34  wherein the scale inhibited is calcium carbonate, halite, calcium sulfate, barium sulfate, strontium sulfate, iron sulfide, lead sulfide and zinc sulfide or mixtures thereof. 
   
   
       36 . A biodegradable dispersant composition for use in water treatment and oil field systems comprising the graft copolymer of  claim 1 , wherein the copolymer comprises greater than about 20% by weight, based on total weight of the copolymer, of glycerol, monosaccharide, disaccharide, oligosaccharide, polysaccharide or mixtures thereof as the chain terminating portion of the copolymer. 
   
   
       37 . A brine compatible polymer for use in oil field systems comprising the graft copolymer of  claim 1 , wherein the brine compatible polymer is soluble at a dose of at least 5 ppm in a brine containing at least 35 grams per liter of salt. 
   
   
       38 . The brine compatible polymer according to  claim 37  wherein the copolymer comprises at least about 20% by weight, based on total weight of the graft copolymer, of glycerol, monosaccharide, disaccharide, oligosaccharide, polysaccharide, or mixtures thereof as the hydroxyl-containing natural moiety of the copolymer. 
   
   
       39 . A method of cementing a subterranean zone penetrated by a well bore comprising:
 preparing a cement composition comprised of a hydraulic cement, sufficient water to form a slurry and the graft copolymer of  claim 1 ;   placing said cement composition in said subterranean zone; and   allowing said cement composition to set into a hard impermeable mass therein.