Preparation method and application of polyhydrazide with viscosity-lowering, pour-point-lowering and corrosion-inhibiting effects

Abstract

The invention relates to a method for preparing polyhydrazide with effects on lowering viscosity, lowering coagulability and inhibiting corrosion and application thereof. The method comprises the steps of dissolving natural oil and fat into a first organic solvent in a reactor, adding a hydrazine hydrate solution, heating for refluxing, and cooling to room temperature; pouring the first organic solvent out of the reactor, wherein a remaining faint-yellow fat-like substance is long-chain fatty hydrazide; adding a second organic solvent into the reactor while stirring, adding a cross-linking agent and alkali into the reactor, heating reactants in a vessel, cooling to room temperature, and filtering to remove insoluble matters, thereby obtaining a pale-yellow polyhydrazide solution; or evaporating to remove the second organic solvent from the pale-yellow polyhydrazide solution, so as to obtain pale-yellow waxy solids, namely polyhydrazide. The polyhydrazide is used as a crude oil additive and can lower the thermal stability of a comb polymer additive in crude oil and the crystal nucleus distorting effect of polar groups; meanwhile, the polyhydrazide can be adsorbed to the surface of metal through the coordination between nitrogen and oxygen atoms and metal, so as to form an organic protective layer to play a role in inhibiting corrosion.

Description

technical field [0001] The invention relates to the technical field of polyhydrazides, in particular to a preparation method and application of polyhydrazides with functions of reducing viscosity, pour point and corrosion. Background technique [0002] Polymers with long alkyl side chains and comb-shaped polymers are an important class of polymers, such as polyacrylic high carbon alcohol ester, polyacrylic acid high carbon amine amide, polymaleic acid high carbon alcohol ester, polymaleic acid high carbon amine Copolymers of amides and their monomers or copolymers with monomers such as styrene and vinyl acetate, etc. This type of polymer can be used as a pour point depressant for high-point crude oil, a viscosity depressant for high-viscosity crude oil, a wax inhibitor for crude oil, a drag reducer for crude oil transportation, and other oilfield chemicals. At present, the main chain of this type of polymer used is a long alkyl chain, which functions as connecting side cha...

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Problems solved by technology

However, there are many problems in practical applications, such as: the thermal stability of the main chain of the alkyl group is strong, and it is difficult to decompose into short-chain compounds in the refining stage after adding crude oil, and it is easy to form gel or carbon deposits; the long-chain alkyl group in the polymer The side has a structure similar to the wax in crude oil, and is easy to eutectic or adsorb with it. The polar part of the polymer plays the role of distorting the crystal nucleus, dispersing the wax crystal or inhibiting the further growth of the wax crystal, but the alkyl The polarity of the main chain is small and the effect is weak, relying on the twisted crystal nucleus of the ester group or amide group on the side chain