Abstract: Novel corrosion inhibiting compositions comprising a combination of amino thiol or amino disulfide compounds with acidic amino acid polymers inhibit carbon dioxide induced corrosion of ferrous metals in aqueous systems. Particularly effective inhibitor compositions are the natural amino acids cysteine and cystine and their decarboxylated analogues cysteamine and cystamine in combination with polyaspartic acid. The inhibitor compositions are particularly useful for preventing corrosion and scale formation in oil production applications.

Abstract: Novel corrosion inhibiting compositions comprising a combination of amino thiol or amino disulfide compounds with acidic amino acid polymers inhibit carbon dioxide induced corrosion of ferrous metals in aqueous systems. Particularly effective inhibitor compositions are the natural amino acids cysteine and cystine and their decarboxylated analogues cysteamine and cystamine in combination with polyaspartic acid. The inhibitor compositions are particularly useful for preventing corrosion and scale formation in oil production applications.

Abstract: Carbon dioxide induced corrosion of ferrous metals in aqueous systems is inhibited by treatment of the aqueous system with corrosion inhibiting amino thiol and amino disulfide compounds. Particularly effective inhibitors are the natural amino acids cysteine and cystine and their decarboxylated analogues cysteamine and cystamine. Novel corrosion inhibiting compositions comprising a combination of amino thiol or amino disulfide compounds with acidic amino acid polymers are also disclosed.

Abstract: A method for the preparation of a succinimide copolymer by the catalytic co-polymerization of aspartic acid with a selected polyfunctional monomer in the presence of a cyclic carbonate solvent. Succinimide copolymers of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading.

Abstract: A composition and method is disclosed for inhibiting the corrosion of metals in contact with an aqueous system capable of corroding the metal. The inventive composition contains a substantially water-soluble polymer of an acidic amino acid and at least one water-soluble salt of molybdenum or zinc. The composition is substantially non-toxic and environmentally acceptable and is supplied in a corrosion-inhibition amount to the otherwise metal-corrosive aqueous system.

Abstract: A method for the preparation of a succinimide copolymer by the catalytic co-polymerization of aspartic acid with a selected polyfunctional monomer in the presence of a cyclic carbonate solvent. Succinimide copolymers of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading.

Abstract: A method for the preparation of a succinimide copolymer by the catalytic co-polymerization of aspartic acid with a selected polyfunctional monomer in the presence of a cyclic carbonate solvent. Succinimide copolymers of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading.

Abstract: Polysuccinimide of varying molecular weight has been prepared in a solvent system by heat polymerization of aspartic acid. The solvent system includes a sulfur oxygen acid and a sulfur oxygen acid salt. In a preferred embodiment, aspartic acid is polymerized in a liquid solvent reaction mixture at a temperature in the range of about 110.degree. C. to about 320.degree. C.

Abstract: Disclosed are methods of producing super-absorbing polymeric networks of polyaspartates from crosslinked polysuccinimide. In one preferred aspect, polysuccinimide is first reacted with an organic crosslinking agent, preferably an organic base containing at least two primary amine groups, to form a gelled crosslinked polysuccinimide. The gelled crosslinked polysuccinimide is then base hydrolyzed to a gelled polymeric network of polyaspartate and deswollen with at least one liquid alcohol to a polymeric network of polyaspartate which demonstrates super-absorbing capability in water and in electrolyte solution. Super-absorbing polymeric networks of polyaspartates can also be produced in a single reaction vessel by sequentially crosslinking a polysuccinimide with an organic crosslinking agent in an aqueous reaction medium, optionally containing a mineral acid, and then hydrolyzing the crosslinked polysuccinimide to produce a polymeric network of polyaspartate.

Abstract: Super-absorbing polymeric networks of crosslinked polyaspartates are produced from crosslinked polysuccinimide. Super-absorbing polymeric networks are produced in a single reaction vessel by crosslinking polysuccinimide with at least one organic polyamine crosslinking agent in the presence of at least one nitrogenous base. The reaction is carried out in an aqueous reaction mixture to produce a polymeric network of crosslinked polyaspartate.

Abstract: A method for the preparation of a succinimide copolymer by the catalytic co-polymerization of aspartic acid with a selected polyfunctional monomer in the presence of a cyclic carbonate solvent. Succinimide copolymers of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading.

Abstract: A method for the preparation of a desired molecular weight polysuccinimide by the catalytic polymerization of aspartic acid in the presence of a thioether solvent. Polysuccinimide of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading and relatively low temperatures.

Abstract: A method for the preparation of a desired molecular weight polysuccinimide by the catalytic polymerization of aspartic acid in the presence of a cyclic carbonate solvent. Polysuccinimide of relatively high weight average molecular weight and high purity can be produced in relatively high yields while employing a relatively low catalyst loading.

Abstract: Tree seedlings, especially pine tree nursery seedlings, are treated, for example, by a root soak with a water-soluble, polyorganic acid, having a molecular weight size of more than 1,500 Daltons. Particularly suitable for this purpose are polyamino acids such as polyaspartic acid.

Abstract: The present invention is directed to a method for the production of D,L-aspartic acid. The method comprises reacting an unsaturated dicarboxylic acid or anhydride, such as, maleic acid, fumaric acid, maleic anhydride, or mixtures thereof, with excess aqueous ammonia at an elevated temperature and pressure for a time sufficient to produce diammonium D,L-aspartate. The produced diammonium D,L-aspartate is then neutralized to D,L-aspartic acid. Excess unreacted ammonia and various by-products may be recycled and re-used in the method, thereby minimizing waste and reducing cost. The produced D,L-aspartic acid may be subsequently used to make polyaspartic acid.

Abstract: The present invention is directed to a method for the production of D,L-aspartic acid. The method comprises reacting an unsaturated dicarboxylic acid or anhydride, such as, maleic acid, fumaric acid, maleic anhydride, or mixtures thereof, with excess aqueous ammonia at an elevated temperature and pressure for a time sufficient to produce diammonium D,L-aspartate. The produced diammonium D,L-aspartate is then neutralized to D,L-aspartic acid. Excess unreacted ammonia and various by-products may be recycled and re-used in the method, thereby minimizing waste and reducing cost. The produced D,L-aspartic acid may be subsequently used to make polyaspartic acid.

Abstract: This invention relates to enhancing plant productivity employing a method and improved compositions containing water-soluble crosslinked polyamino acids having a weight average molecular weight of a size larger than about 1,500. More particularly, crosslinked polyamino acids enhance plant productivity when supplied to the plant directly as the free acid or salt thereof or hydrolyzed from a crosslinked precursor of the crosslinked polyamino acid by the method disclosed. Particularly suitable for this purpose are water-soluble, crosslinked polyaspartic acid, and salts thereof and hydrolyzed crosslinked polysuccinimide.

Abstract: Plant productivity in a hydroponic medium is enhanced by the addition of a water-soluble, non-biodegradable, non-peptidal polymeric acid having a molecular size larger than about 1,500 Daltons.

Abstract: Disclosed are methods of producing super absorbing polymeric networks of polyaspartates from crosslinked polysuccinimide. In one preferred method aspect, polysuccinimide is first reacted with an organic crosslinking agent, preferably an organic base containing at least two primary amine groups to form crosslinked polysuccinimide. The crosslinked polysuccinimide is then hydrolyzed to a polymeric network of polyaspartate which demonstrates super absorbing capability in water and in saline solution. Alternative method aspects are disclosed in which super absorbing polymeric networks of polyaspartates are produced in a single reaction vessel by sequentially crosslinking polysuccinimide with organic crosslinking agent in an aqueous reaction mixture and then hydrolyzing the reaction product to produce a polymeric network of polyaspartate.

Abstract: Aspartic acid precursors such as mono and diammonium maleate, maleamic acid, ammonium maleamate, ammonium malate and mixtures of these and other precursors are copolycondensed thermally with a variety of mono, di and multifunctional monomers containing amino, hydroxyl and carboxyl functional groups. The resulting condensation copolymers and terpolymers contain succinimide units derived from aspartic acid precursors, condensed with other functional group monomers usually .?.though.!. .Iadd.through .Iaddend.amide and ester linkages. Hydrolysis of the polysuccinimide copolymers and terpolymers with alkali, alkaline earth and ammonium hydroxide produces aspartic acid copolymer and terpolymer salts.