Compounds, compositions and methods are provided for reducing, inhibiting, or preventing corrosion of a surface, using a polyester polyamine compound. The polyester polyamine compound having a structure corresponding to Formula 1 or 2, or a salt thereof:

##STR00001##

wherein R.sub.1 is independently alkylene; R.sub.2 is independently hydrogen or —COR.sub.4; R.sub.3 is independently alkyl, alkenyl, aryl, or alkaryl; R.sub.4 is independently alkyl or alkenyl; R.sub.10 and R.sub.11 are each independently hydrogen, alkyl, or alkaryl; m is an integer from 1 to 10; n is an integer from 3 to 10; and wherein at least one R.sub.2 is —COR.sub.4.

A photometric method for determination of a concentration of a film forming amine in a liquid, including providing a buffer solution of a weak acid having a pKa≥4.5 and a strong acid having a pKa≤1; diluting an aliquot of the buffer solution with water, and determining the pH of the diluted buffer solution; adding reagent to the diluted buffer solution and measuring an initial absorbance of the diluted buffer/reagent solution; preparing a sample solution by adding liquid containing the film forming amine to an aliquot of the buffer solution and measuring the pH of the sample solution; adjusting the pH of the sample solution to match the pH of the diluted buffer solution by adding strong acid; and adding the reagent to the pH adjusted sample solution to form a colored complex, and measuring the absorbance of the resulting solution in a photometer.

The present disclosure provides a bis-quaternary ammonium salt of Formula I ##STR00001##
wherein A is selected from O, NH, S, C(O), C(NH) or C(S); R.sub.1 and R.sub.2 are independently selected from C.sub.1-3 alkyl or H; R.sub.3 is C.sub.1-16 alkyl, C.sub.13-20 aralkyl or C.sub.2-16 allyl; X.sup.− is selected from chloro, bromo, iodo, hydroxide, nitrate or sulphate; and n and m are independently 1 to 6. Furthermore, a corrosion inhibition formulation comprising said bis-quaternary ammonium salt is revealed. Also, convenient processes for the preparation of the salt of Formula I and the formulation are provided.

A corrosion inhibitor for a central heating system is provided in the form of a cream having low water content, which may be encapsulated within a water-soluble film, for example a poly (vinyl alcohol) film. The corrosion inhibitor product is more highly-concentrated than known liquid inhibitors, and the encapsulation in a water soluble film provides for safer handling and eliminates waste from plastic packaging.

A composition comprising a) a quaternary trialkylalkanolamine hydroxide and b) at least one diamine as component b), which is selected from the group consisting of 1-amino-4-methylpiperazine, 1,2-diaminopropane and mixtures thereof.

Disclosed are oleyl propylenediamine-based compounds used in compositions and methods for inhibiting corrosion. The method comprises introducing into a fluid source a composition comprising one or more oleyl propylenediamine-based compounds comprising Formula I:

##STR00001##

wherein Y.sub.1, Y.sub.2, and Y.sub.3 independently are hydrogen or a substituent of Formula (II):

##STR00002##

wherein V is —O— or —NH—, W is optionally present and is a linear or branched C.sub.1-10 aliphatic group, X is —H, —NZ.sub.3.sup.+, —COOH, —SO.sub.3H, —OSO.sub.3H.sub.2, —PO.sub.3H, —OPO.sub.3H.sub.2, or a salt thereof, each Z independently is hydrogen or a linear or branched C.sub.1-20 aliphatic group optionally interrupted or substituted with one or more oxygen atoms, and R is hydrogen or methyl, provided that at least one of Y.sub.1, Y.sub.2, or Y.sub.3 is a substituent of Formula (II).

The present invention relates generally to methods for forming peroxyformic acid, comprising contacting formic acid with hydrogen peroxide. The methods for forming peroxyformic acid can include adding formic acid with a relatively lower concentration of hydrogen peroxide, or adding formic acid to a peroxycarboxylic acid composition or forming composition to react with hydrogen peroxide in the compositions. The present invention also relates to peroxyformic acid formed by the above methods. The present invention further relates to the uses of peroxyformic acid for treating a variety of targets, e.g., target water, including target water used in connection with oil- and gas-field operations. The present invention further relates to methods for reducing or removing H.sub.2S or iron sulfide in the treated water source, improving clarity of the treated water source, or reducing the total dissolved oxygen or corrosion in the treated water source, using peroxyformic acid, including peroxyformic acid generated in situ.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

A method of controlling corrosion in a subsea pipeline is disclosed which includes supplying a low dose inhibitor stream (LDHI) comprised of a quaternary amine and drying with a desiccant.

A corrosion inhibiting composition which is a liquid carrier in which is dissolved or dispersed a corrosion inhibitor compound comprising at least one moiety (A) which is an aliphatic, aromatic or mixed aliphatic/aromatic structure containing one or more hetero atoms which are nitrogen, oxygen, phosphorus or sulphur, and also at least one moiety (B) which contains one or more polymerisable groups containing double or triple bonded carbon, with the moieties (A) and (B) directly or indirectly covalently connected together.