Rapid detection method for reaction endpoint of organic peroxide and application of rapid detection method

Abstract

The invention discloses an organic peroxide reaction endpoint rapid detection method and application thereof, and belongs to the technical field of organic chemistry. The invention aims to solve the technical problems that the reaction endpoint of an organic peroxide initiator is difficult to judge, the generated organic peroxide is easy to decompose due to too long reaction time, and the reaction is incomplete and raw materials are remained due to too short reaction time, and provides a rapid detection method for acyl chloride residues in the organic peroxide reaction process. Therefore, the reaction endpoint is determined. According to the technical scheme, the method for rapidly detecting the reaction endpoint of the organic peroxide is characterized in that in the reaction process of an organic peroxide initiator, acyl chloride is gradually consumed, the content is reduced, and the acyl chloride completely reacts when the reaction endpoint is reached. Through reaction of different acyl chloride concentrations and hydroxylamine hydrochloride, a standard curve or a color card is established, the residual amount of acyl chloride is judged, and the reaction endpoint is accurately judged.

Description

Technical Field

[0001] This invention relates to the field of organic chemistry, specifically to a rapid detection method for the reaction endpoint of organic peroxides and its application. Background Technology

[0002] For understanding the technical content of this invention: Organic peroxide initiators, such as tert-butyl peroxynedecanoate, cumyl peroxynedecanoate, 1,1,3,3-tetramethylbutyl peroxynedecanoate, tert-pentyl peroxynedecanoate, 1,1,3,3-tetramethylbutyl peroxynedecanoate, tert-pentyl peroxynedecanoate, tert-butyl peroxynedecanoate, tert-butyl peroxyneonanoate, tert-pentyl peroxyacetate, and di(2-ethylhexyl peroxide), are mainly used in the polymerization reactions of styrene, ethylene, vinyl chloride, and propylene. The production process works by forming R-OO- groups of organic peroxides (such as tert-propyl peroxide, hydrogen peroxide, etc.) under alkaline conditions. These groups react with corresponding acyl chlorides (such as neodecanoyl chloride, 2-ethylhexyl chloroformate) R-COCl to form organic peroxide initiator products (cumyl peroxynedecanoate, 2-ethylhexyl peroxydicarbonate)).

[0003] These organic peroxides are unstable substances; the peroxide bonds (-OO-) in their molecules are easily broken, and they readily decompose upon heating, generating free radicals. This decomposition is typically an exothermic reaction. Their half-life is lower than that of other substances, and it is a function of temperature, strongly dependent on temperature; the higher the temperature, the shorter the half-life. The half-lives of the aforementioned initiators are shown in the attached table. A certain temperature is required to maintain the reaction rate, and the temperature must be maintained for a certain time to preserve the reaction yield. However, organic peroxides are easily decomposed by heat; excessively long reaction times lead to the decomposition of the generated organic peroxides, while excessively short reaction times result in incomplete reactions and residues of reactants.

[0004] During the reaction of the organic peroxidation initiator, the acyl chloride is gradually consumed and its content decreases until the reaction endpoint is reached, at which point the acyl chloride is completely reacted. By reacting different concentrations of acyl chloride with hydroxylamine hydrochloride, a standard curve or color chart is established to determine the remaining amount of acyl chloride and accurately determine the reaction endpoint.

[0005] Relevant patent documents retrieved: This document, published in China (CN120647564A) on September 16, 2025, discloses a method for preparing tert-butyl peroxyneodecanate. Zinc oxide is uniformly dispersed in nanoparticle form on a graphene oxide / attapulgite composite support via a hydrothermal method, forming a supported catalyst with a high specific surface area. This fully exposes the active sites, significantly improving catalytic efficiency. A strong interaction is formed between the zinc oxide and the support. The reaction process is optimized by adapting the alkaline system, and the composite catalyst is effective in the oxidation of hydrogen... The sodium / tert-butyl hydroperoxide system exhibits high selectivity, with byproduct residues ≤0.01%, and the reaction conditions are mild, requiring no high-temperature or high-pressure equipment. The catalyst is recyclable, and the metal ion content in the waste liquid is ≤0.1ppm. The literature mentions using 0.5%-4% of neodecanoyl chloride by mass, controlling the temperature at 15-30℃, adding 90%-98% neodecanoyl chloride at a rate of 0.5-2 mL / min over 20-60 min, and continuing stirring for 0.5-3 h after addition. However, the reaction time is relatively long, making it impossible to determine the reaction endpoint, and the process involves significant losses.

[0006] This document, published in China (CN110981778A) on April 10, 2020, discloses a method for preparing cumene hydroperoxide (CNP) and a solvent-based CNP. The method includes synthesis and purification steps. A water-in-oil emulsion is obtained by reacting cumene hydroperoxide, an alkaline solution, and neodecanoyl chloride. The emulsion is then washed with four different treatment agents, allowed to stand, and the water is separated to obtain the final product. The dry basis mass ratio of cumene hydroperoxide to neodecanoyl chloride is 0.8-1.0:1, the addition time is 45-60 min, the temperature is 25-35℃, the reaction time is 60-90 min, and the emulsion is allowed to stand for 30-45 min before water separation. The reaction temperature of 35℃ is close to the 10-hour half-life of 38℃; improper time control can easily lead to process decomposition, affecting the yield.

[0007] Relevant non-patent literature retrieved: The journal title is *Petrochemical Technology*, the document title is "Spectrophotometric Determination of Isononanoyl Chloride and Pteropenoyl Chloride", Volume 12, Publication Date: September 28, 1983. This document discloses that isononanoyl chloride, etc., react with hydroxylamine reagent under certain conditions to form hydroxamic acid. The hydroxamic acid forms a complex with ferric ions, resulting in color development, with maximum absorption at 550 nm in the visible light spectrum. In the experimental procedure, the reflux temperature is controlled at 72℃, and the reaction of the acyl chloride with hydroxylamine reagent is allowed for 15 minutes. Adjusting the pH to 1-2 results in the formation of a purple-red complex with relatively stable absorbance. However, this method requires heating and reflux for color development. Organic peroxides are prone to decomposition upon heating, and the reaction is violent, with -OO- bonds breaking and generating a large number of free radicals with extremely strong oxidizing properties, which oxidize and deactivate other organic compounds, preventing color development. Furthermore, heating organic peroxides produces a large amount of gas, posing an explosion risk, making the experiment quite risky.

[0008] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: (1) The operation steps are cumbersome and the detection time is long. The relevant evidence is: Publication No. CN120647564A, which states that the dropping time is 20-60 min and the reaction is continued to be stirred for 0.5-3 h after dropping. The reaction time span is long in this process, and the reaction endpoint cannot be determined. There is a lot of loss in the process. (2) The process requirements are high. The relevant evidence is: the literature title is "Spectrophotometric determination of isononanoyl chloride and pentanoyl chloride". In the experimental operation, the reflux temperature is controlled at 72°C. If the temperature is higher or lower than this, the detection effect will be worse. The control of process temperature and other factors needs to be extremely strict. Summary of the Invention

[0009] The purpose of this invention is to provide: A rapid detection method for the reaction endpoint of organic peroxides, and related technologies, to solve technical problems such as the rapid detection of acyl chloride residues during the reaction of organic peroxides, thereby determining the reaction endpoint, or a combination thereof.

[0010] Terminology Explanation: Unless otherwise defined, all technical terms in this document have the same meanings as commonly understood by one of ordinary skill in the art to which the subject matter of the claims pertains. Unless otherwise stated, all patents, patent inventions, and publications cited in this document are incorporated herein by reference in their entirety. If multiple definitions exist for terms in this document, the definitions in this chapter shall prevail.

[0011] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0012] Definitions of standard chemical terms can be found in the references "Organic Chemistry" and "Oxford Dictionary of Organic Chemistry".

[0013] Unless otherwise stated, conventional methods within the scope of the art, such as carbon NMR spectroscopy, hydrogen NMR spectroscopy, ion chromatography, and gas chromatography, shall be used.

[0014] Unless specifically defined herein, the use of all commercially available products herein employs standard techniques. For example, it may be carried out using the manufacturer's instructions for use with the kit, or in accordance with methods known in the art or the description of this invention. The techniques and methods described herein can generally be implemented according to conventional methods well known in the art, based on the descriptions in the various summary and more specific documents cited and discussed in this specification.

[0015] The term "organic peroxide" as used in this article refers to a class of organic compounds containing an organic peroxide group (-OO-) in their molecules. It is an important branch of peroxides (distinct from inorganic peroxides such as hydrogen peroxide). As a core class of free radical polymerization initiators (such as tert-butyl peroxyneodecanate and di(2-ethylhexyl)dicarbonate peroxide), it is generated by the reaction of peroxides (such as tert-butyl hydrogen peroxide) with acyl chlorides (such as neodecanoyl chloride).

[0016] The term "reaction endpoint" as used in this article refers to the critical point in a chemical reaction where reactants (such as acyl chloride and peroxide) reach the expected degree of reaction (complete reaction or a specific conversion rate). It is a key point for terminating the reaction and ensuring the purity of the product.

[0017] The term "acyl chloride" as used in this article refers to carboxylic acid derivatives with the general formula R-COCl (R being alkyl, aryl, heterocyclic, etc.), formed by replacing the hydroxyl group (-OH) in the carboxyl group (-COOH) with a chlorine atom (-Cl). Its core functional group is the acyl chloride group (-COCl). It exhibits extremely high reactivity, readily undergoing acylation reactions with alcohols, amines, peroxides, etc., and is an important acylation reagent in organic synthesis. Key raw materials in the synthesis of organic peroxides (such as neodecanoyl chloride and 2-ethylhexyl chloroformate) react with peroxides to generate peroxidized carboxylic acid ester initiators.

[0018] The term "hydroxylamine hydrochloride" as used in this article refers to: hydroxylamine hydrochloride with the chemical formula NH₂OH HCl is an inorganic compound, the hydrochloride salt of hydroxylamine (NH2OH), which is a white crystalline solid and readily soluble in solvents such as water and ethanol. It exhibits reducing and nucleophilic properties, with the hydroxylamine group (-NH-OH) capable of specific reactions with functional groups such as acyl chlorides, esters, and ketones.

[0019] The term "hydroxyoxime acid" as used in this article refers to an organic compound with the general formula R-CO-NHOH, formed by the reaction of acylation reagents such as acyl chlorides and esters with hydroxylamine (or hydroxylamine hydrochloride), with the core functional group being a hydroxyoxime group (-CO-NHO-). It possesses specific complexing ability and can react with ferric ions (Fe3+). 3+ It forms a stable red / purple complex that has strong absorption in the visible region (approximately 500-550 nm).

[0020] The term "ferric chloride colorimetric reagent" used in this article refers to a colorimetric reagent with ferric chloride (FeCl3) as its core component. Ferrous ions can form colored complexes with compounds such as hydroxamic acid and phenols. The color and absorption wavelength of the complexes vary depending on the ligand structure.

[0021] The term "neodecanoyl chloride" as used in this article refers to: [a chemical formula of C...] 10 H 19 COCl, an aliphatic acyl chloride, is an acyl chloride derivative of neodecanoic acid, appearing as a colorless to pale yellow oily liquid. It is a core raw material for the synthesis of peroxynedecanoate initiators (such as tert-butyl peroxynedecanoate and tert-amyl peroxynedecanoate). The term "2-ethylhexyl chloroformate" as used in this article refers to: [the chemical formula is C9H]. 17 O2Cl is a carbonate acyl chloride with a chloroformate group (-O-COCl) as its core functional group. It is a colorless and transparent liquid and is the core raw material for the synthesis of di(2-ethylhexyl) peroxide (EHP) (reacting with hydrogen peroxide).

[0022] The term "w / v%" used in this article refers to core concentration, which is "mass / volume percentage" and is used to quantitatively describe "the mass percentage of solute contained in a unit volume of solution". It is a commonly used method for expressing concentration in solid-liquid and gas-liquid solution systems.

[0023] The term "absorbance" used in this article refers to optical density (OD), which is the degree to which a substance absorbs light of a specific wavelength, following the Lambert-Beer law. It has a linear relationship with the concentration of the substance (within a certain concentration range) and is a core parameter for quantitative analysis; it is unitless.

[0024] In a first aspect, the present invention provides: a rapid detection method for the reaction endpoint of organic peroxides, comprising the following steps: (1) Constructing the standard color gradient of acyl chloride: S1. Acyl chloride solution: Acyl chloride is dissolved in a solvent to obtain a series of acyl chloride solutions with an acyl chloride content of 0w / v%-30w / v%, wherein the solvent is at least one of ethanol and isopropanol; S2. Alkaline hydroxylamine hydrochloride solution: Dissolve hydroxylamine hydrochloride in a solvent, add an alkaline substance to obtain an alkaline hydroxylamine hydrochloride solution with a concentration of 30w / v%-50w / v%. S3. Mix the series of acyl chloride solutions obtained in S1 and the alkaline hydroxylamine hydrochloride solution obtained in S2 in equal volumes, and then react them with ferric chloride colorimetric reagent to obtain the standard color gradient of acyl chloride. (2) Sample detection: Mix the sample from the organic peroxide reaction process with an equal volume of the acyl chloride solution described in step (1) and an equal volume of alkaline hydroxylamine hydrochloride solution, and then react with ferric chloride colorimetric reagent to obtain the sample test sample; The organic peroxide is one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate. In step (2), the amount of ferric chloride colorimetric reagent added is the same as that added in step (1); (3) Result determination: Visually compare the color of the sample test sample obtained in step (2) with the color gradient of the acyl chloride standard in step (1) to determine the remaining acyl chloride content.

[0025] The technical features include: acyl chloride solution, alkaline hydrochloric acid hydroxylamine solution, equal volume mixing, ferric chloride colorimetric reagent, and samples in the reaction process of organic peroxides.

[0026] Wherein, the acyl chloride in S1 is one of 2-ethylhexyl chloroformate, neodecanoyl chloride, tervapotranyl chloride, and isononanoyl chloride; The acyl chloride in S1 is preferably one of 2-ethylhexyl chloroformate and neodecanoic acid chloride; The acyl chloride in S1 is further preferably neodecanoyl chloride; Preferably, the solvent for the acyl chloride solution in S1 is isopropanol; Wherein, the acyl chloride concentration of the acyl chloride solution described in S1 is 0 w / v%-30 w / v%, for example: The acyl chloride concentration of the acyl chloride solution described in S1 can be 0w / v%-10w / v%, 0w / v%-20w / v%, 0w / v%-5w / v%, 0w / v%-25w / v%, 0w / v%-15w / v%, or 0w / v%-28w / v%. To give another example, The concentration of the acyl chloride solution described in S1 can also be 0 w / v%, 5 w / v%, 10 w / v%, 20 w / v%, or 30 w / v%. The concentration of the acyl chloride solution described in S1 can also be 0 w / v%, 1 w / v%, 2 w / v%, 3 w / v%, 4 w / v%, 5 w / v%. Wherein, the solvent of the alkaline hydroxylamine hydrochloride solution in S2 is at least one of water, methanol, ethanol, and isopropanol; The solvent for the alkaline hydroxylamine hydrochloride solution described in S2 is preferably water; The solvent for the alkaline hydroxylamine hydrochloride solution in S2 is further preferably at least one of deionized water, purified water, ultrapure water, and drinking water. The solvent for the alkaline hydroxylamine hydrochloride solution is more preferably deionized water; Wherein, the alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, and pyridine; The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is preferably at least one of sodium hydroxide, sodium bicarbonate, and sodium carbonate. The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is further preferably sodium hydroxide; The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is more preferably 6% sodium hydroxide; Preferably, the concentration of hydroxylamine hydrochloride in S2 is 30w / v%-40w / v%. More preferably, the concentration of hydroxylamine hydrochloride in S2 is 40 w / v% Preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is in the range of 10-13; More preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is 12; The solvent for the ferric chloride colorimetric agent described in S3 is an acidic solvent; The solvent for the ferric chloride colorimetric agent described in S3 is preferably at least one of hydrochloric acid and sulfuric acid; Preferably, the concentration of the acidic solvent is 3wt%-10wt%; More preferably, the concentration of the acidic solvent is 5 wt%; The concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 0.1wt%-2wt%. The preferred concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 1 wt%. The reaction conditions described in S3 are: reaction at room temperature for 1-5 minutes; The preferred reaction conditions for S3 are: reacting at room temperature for 3 minutes; Wherein, the volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 5-30:5-30:1-5; The preferred volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 10:10:2. Preferably, the container used to react with the ferric chloride colorimetric reagent in step S3 is at least one of a volumetric flask and a colorimetric tube; More preferably, the container used to react with the ferric chloride colorimetric reagent in step S3 is a colorimetric tube; More preferably, the container used for the reaction with the ferric chloride colorimetric reagent in step S3 is a 100mL colorimetric tube; Preferably, the container used in step (2) to react with the ferric chloride colorimetric reagent is at least one of a volumetric flask and a colorimetric tube; More preferably, the container used in step (2) to react with the ferric chloride colorimetric agent is a colorimetric tube; More preferably, the container used for the reaction with the ferric chloride colorimetric reagent in step (2) is a 100mL colorimetric tube; Preferably, the reaction formula of the rapid detection method is: Reaction formula: R-COCl + NHOH + NaOH → R-CONHONa + NaCl + H2O; Color rendering: R-CONHONa + FeCl3+ H + → [R-CONHO]3Fe (dark red complex).

[0027] Based on further solutions to the technical problems of the present invention, or simultaneous solutions to multiple technical problems, the preferred solution in the technical solution provided in the first aspect of the present invention includes: The first preferred option: The acyl chloride in S1 is one of 2-ethylhexyl chloroformate, neodecanoyl chloride, pentanoyl chloride, and isononanoyl chloride; preferably one of 2-ethylhexyl chloroformate and neodecanoyl chloride; and more preferably neodecanoyl chloride. This technical solution, based on solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency", further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency".

[0028] The second preferred option is to use isopropanol as the solvent for the acyl chloride solution in S1. This technical solution, while solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency," further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency."

[0029] The third preferred option: the alkaline substance in the alkaline hydroxylamine hydrochloride solution described in S2 is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, and pyridine; preferably at least one of sodium hydroxide, sodium bicarbonate, and sodium carbonate; further preferably sodium bicarbonate; and even more preferably 6% sodium bicarbonate. This technical solution, while solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency," further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency."

[0030] The fourth preferred option: the concentration of hydroxylamine hydrochloride in S2 is 30w / v%-40w / v; preferably, the concentration of hydroxylamine hydrochloride in S2 is 40w / v. This technical solution, based on solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency", further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency".

[0031] The fifth preferred embodiment: the solvent for the ferric chloride colorimetric reagent described in S3 is an acidic solvent; the solvent is preferably at least one of hydrochloric acid, sulfuric acid, phosphoric acid, and acetic acid; more preferably at least one of hydrochloric acid and sulfuric acid; even more preferably hydrochloric acid; preferably, the concentration of the acidic solvent is 3wt%-10wt%; even more preferably, the concentration of the acidic solvent is 5wt%. This technical solution, while solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency," further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency."

[0032] The sixth preferred option: the concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 0.1wt%-2wt%; preferably 1wt%. This technical solution, based on solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency", further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency".

[0033] The seventh preferred option: The reaction conditions described in S3 are: reaction at room temperature for 1-5 minutes; preferably: reaction at room temperature for 3 minutes. This technical solution, based on solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency", further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency".

[0034] The eighth preferred embodiment: the volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 5-30:5-30:1-5; preferably 10:10:2. This technical solution, based on solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency", further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency".

[0035] Secondly, the present invention provides the application of the rapid detection method in organic peroxide reactions.

[0036] This includes technical features: organic peroxide reaction and application.

[0037] Preferably, the organic peroxide is an organic peroxide-based polymerization initiator; More preferably, the organic peroxide polymerization initiator is selected from one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate. The application involves a method for preparing hydroxamic acid (R-CONHOH) by reacting acyl chloride with hydroxylamine hydrochloride under alkaline conditions, and quantitatively identifying the product using a ferric chloride colorimetric reaction. During the organic peroxidation initiator reaction, the acyl chloride is gradually consumed, decreasing in content, and completely reacts at the reaction endpoint. By reacting different concentrations of acyl chloride with hydroxylamine hydrochloride, the remaining amount of acyl chloride is determined, accurately identifying the reaction endpoint.

[0038] The preferred application is as follows: Acyl chloride is a highly reactive acylation reagent. Hydroxylamine hydrochloride is neutralized under alkaline conditions, releasing free hydroxylamine. Its nitrogen atom acts as a nucleophilic center, attacking the carbonyl carbon of the acyl chloride, undergoing a nucleophilic addition-elimination process to generate a hydroxamic acid. The acid produced in the reaction is neutralized by excess base, driving the reaction to completion. This reaction rate is extremely fast, and the color of the product is directly proportional to the acyl chloride content, as indicated by FeCl3.

[0039] Thirdly, this invention provides: a rapid detection method for the reaction endpoint of organic peroxides, comprising the following steps: (1) Constructing the standard color gradient of acyl chloride: S1. Acyl chloride solution: Acyl chloride is dissolved in a solvent to obtain a series of acyl chloride solutions with an acyl chloride content of 0w / v%-30w / v%, wherein the solvent is at least one of ethanol and isopropanol; S2. Alkaline hydroxylamine hydrochloride solution: Dissolve hydroxylamine hydrochloride in a solvent, add an alkaline substance to obtain an alkaline hydroxylamine hydrochloride solution with a concentration of 30w / v%-50w / v%. S3. Mix the series of acyl chloride solutions obtained in S1 with the alkaline hydroxylamine hydrochloride solution obtained in S2 in equal volumes, and then react them with ferric chloride colorimetric reagent to obtain a series of standard reaction solutions. S4. Measure the absorbance of the series of standard reaction solutions obtained in S3 to establish a standard curve for acyl chloride; (2) Sample detection: Mix the sample from the organic peroxide reaction process with an equal volume of the acyl chloride solution described in step (1) and an equal volume of alkaline hydroxylamine hydrochloride solution, and then react with ferric chloride colorimetric reagent to obtain the sample test sample; The organic peroxide is one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate. In step (2), the amount of ferric chloride colorimetric reagent added is the same as that added in step (1); (3) Result determination: The absorbance of the sample obtained in step (2) is measured, and the acyl chloride content is accurately calculated using the acyl chloride standard curve established in step (1).

[0040] The technical features include: acyl chloride solution, alkaline hydrochloric acid hydroxylamine solution, equal volume mixing, ferric chloride colorimetric reagent, sample in the organic peroxide reaction process, and absorbance.

[0041] Wherein, the acyl chloride in S1 is one of 2-ethylhexyl chloroformate, neodecanoyl chloride, tervapotranyl chloride, and isononanoyl chloride; Preferably, the solvent for the acyl chloride solution in S1 is isopropanol; Wherein, the acyl chloride concentration of the acyl chloride solution described in S1 is 0 w / v%-30 w / v%, for example: The acyl chloride concentration of the acyl chloride solution described in S1 can be 0w / v%-10w / v%, 0w / v%-20w / v%, 0w / v%-5w / v%, 0w / v%-25w / v%, 0w / v%-15w / v%, or 0w / v%-28w / v%. To give another example, The concentration of the acyl chloride solution described in S1 can also be 0 w / v%, 5 w / v%, 10 w / v%, 20 w / v%, or 30 w / v%. The concentration of the acyl chloride solution described in S1 can also be 0 w / v%, 1 w / v%, 2 w / v%, 3 w / v%, 4 w / v%, 5 w / v%. Wherein, the solvent of the alkaline hydroxylamine hydrochloride solution in S2 is at least one of water, methanol, ethanol, and isopropanol; Wherein, the alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, and pyridine; The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is preferably at least one of sodium hydroxide, sodium bicarbonate, and sodium carbonate. The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is further preferably sodium bicarbonate; The alkaline substance in the alkaline hydrochloric acid hydroxylamine solution described in S2 is more preferably 6% sodium bicarbonate; Preferably, the concentration of hydroxylamine hydrochloride in S2 is 30w / v%-40w / v%. More preferably, the concentration of hydroxylamine hydrochloride in S2 is 40 w / v% Preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is in the range of 10-13; More preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is 12; The solvent for the ferric chloride colorimetric agent described in S3 is an acidic solvent; The solvent for the ferric chloride colorimetric agent described in S3 is preferably at least one of hydrochloric acid and sulfuric acid; The solvent for the ferric chloride colorimetric reagent described in S3 is further preferably hydrochloric acid; Preferably, the concentration of the acidic solvent is 3wt%-10wt%; More preferably, the concentration of the acidic solvent is 5 wt%; The concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 0.1wt%-2wt%. The preferred concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 1 wt%. The reaction conditions described in S3 are: reaction at room temperature for 1-5 minutes; The preferred reaction conditions for S3 are: reacting at room temperature for 3 minutes; Wherein, the volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 5-30:5-30:1-5; The preferred volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 10:10:2. Preferably, the container used to react with the ferric chloride colorimetric reagent in step S3 is at least one of a volumetric flask and a colorimetric tube; More preferably, the container used to react with the ferric chloride colorimetric reagent in step S3 is a colorimetric tube; More preferably, the container used for the reaction with the ferric chloride colorimetric reagent in step S3 is a 100mL colorimetric tube; Preferably, step S3, after reacting with the ferric chloride colorimetric agent, further includes the step of diluting the solution to the mark on the container with a solvent; More preferably, the solvent used for dilution is water; More preferably, the diluent includes, but is not limited to, at least one of deionized water, purified water, ultrapure water, and drinking water; Most preferably, the solvent used for dilution is deionized water; Wherein, the absorbance measuring instrument mentioned in S4 is at least one of ultraviolet spectrophotometer, ultraviolet-visible spectrophotometer, visible spectrophotometer, and fully automatic spectrophotometer; The absorbance measuring instrument mentioned in S4 is preferably at least one of ultraviolet spectrophotometer and ultraviolet-visible spectrophotometer; The absorbance measuring instrument described in S4 is further preferably a UV-Vis spectrophotometer; Preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 500-550 nm; More preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 520-530 nm; More preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 525 nm; Preferably, in S4, the x-axis of the acyl chloride standard curve represents the acyl chloride concentration, and the y-axis represents the absorbance value. Preferably, the container used in step (2) to react with the ferric chloride colorimetric reagent is at least one of a volumetric flask and a colorimetric tube; More preferably, the container used in step (2) to react with the ferric chloride colorimetric agent is a colorimetric tube; More preferably, the container used for the reaction with the ferric chloride colorimetric reagent in step (2) is a 100mL colorimetric tube; Preferably, step (2) further includes a step of diluting the solution to the mark on the container with a solvent after reacting with the ferric chloride colorimetric agent; Among them, the absorbance measuring instrument in step (3) is at least one of ultraviolet spectrophotometer, ultraviolet-visible spectrophotometer, visible spectrophotometer, and fully automatic spectrophotometer; The absorbance measuring instrument in step (3) is preferably at least one of ultraviolet spectrophotometer and ultraviolet-visible spectrophotometer; The absorbance measuring instrument in step (3) is further preferably a UV-Vis spectrophotometer; Preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 500-550 nm; More preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 520-530 nm; More preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 525 nm; Based on further solutions to the technical problems of the present invention, or simultaneous solutions to multiple technical problems, the preferred solution in the technical solution provided in the third aspect of the present invention includes: The first preferred option: The absorbance measuring instrument mentioned in S4 is at least one of a UV spectrophotometer, a UV-Vis spectrophotometer, a visible spectrophotometer, and a fully automated spectrophotometer; preferably, at least one of a UV spectrophotometer and a UV-Vis spectrophotometer; more preferably, a UV-Vis spectrophotometer. This technical solution, while solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency," further solves the technical problem of "even more accurately determining the reaction endpoint and effectively improving detection efficiency."

[0042] The second preferred embodiment: the wavelength range of the UV-Vis spectrophotometer is 500-550 nm; preferably, the wavelength range of the UV-Vis spectrophotometer is 520-530 nm; more preferably, the wavelength range of the UV-Vis spectrophotometer is 525 nm. This technical solution, while solving the technical problem of "accurately determining the reaction endpoint and effectively improving detection efficiency," further solves the technical problem of "more accurately determining the reaction endpoint and effectively improving detection efficiency."

[0043] Embodiments 1-4 of this invention at least support the protection scope of claims 1-3.

[0044] For claims 1-3: acyl chloride solution, hydroxylamine hydrochloride solution, ferric chloride colorimetric agent, and organic peroxide.

[0045] The technical feature "organic peroxide" is summarized from the aforementioned explanation and / or the corresponding technical features in Examples 1-4, such as "organic peroxide polymerization initiator," "tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, pentyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, pentyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, pentyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate," etc., through the common feature "a class of organic compounds containing an organic peroxide group (-OO-) in the molecule." Therefore, those skilled in the art can reasonably presume that the technical feature "organic peroxide," its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "organic peroxide" based on the existing level of technology and within the scope of conventional technical means and common knowledge, should all fall within the protection scope of claims 1-3.

[0046] The technical feature "acyl chloride solution" is derived from the aforementioned explanation and / or the corresponding technical features in Examples 1-4, such as "at least one of 2-ethylhexyl chloroformate, neodecanoyl chloride, pivaloyl chloride, and isononanoyl chloride," through the common feature "a carboxylic acid derivative with the general formula R-COCl (R being an alkyl, aryl, heterocyclic, etc.), generated by replacing the hydroxyl group (-OH) in the carboxyl group (-COOH) with a chlorine atom (-Cl), and the core functional group being an acyl chloride group (-COCl)." Therefore, those skilled in the art can reasonably presume that the technical feature "acyl chloride solution," its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "acyl chloride solution" based on existing technology and conventional technical means and common knowledge should all fall within the protection scope of claims 1-3. For example, replacing "acyl chloride solution" with "neodecanoyl chloride," "pivaloyl chloride," etc., while keeping other technical features unchanged, still falls within the protection scope of claims 1-3 of this invention.

[0047] The technical feature "hydroxylamine hydrochloride solution" is derived from the foregoing explanation and / or the corresponding technical feature in Examples 1-4, such as "the concentration of hydroxylamine hydrochloride is 30w / v%-40w / v%", and is further defined by the common feature "chemical formula is NH2OH". The inorganic compound HCl is summarized as "hydroxylamine (NH2OH) hydrochloride". Therefore, those skilled in the art can reasonably presume that the technical feature "hydroxylamine hydrochloride solution", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "hydroxylamine hydrochloride solution" based on the existing level of technology and conventional technical means and common knowledge should all fall within the protection scope of claims 1-3. For example, replacing "hydroxylamine hydrochloride solution" with "hydroxylamine sulfate" while keeping other technical features unchanged still falls within the protection scope of claims 1-3 of this invention.

[0048] The technical feature "ferric chloride colorimetric agent" is derived from the aforementioned explanation and / or the corresponding technical feature in Examples 1-4, such as "the solvent of the ferric chloride colorimetric agent described in S3 is an acidic solvent," through the common feature "a colorimetric reagent with ferric chloride (FeCl3) as the core component." Therefore, those skilled in the art can reasonably infer that the technical feature "ferric chloride colorimetric agent," its subordinate concepts, its essentially equivalent technical means, and technical means that can replace "ferric chloride colorimetric agent" based on existing technology and conventional technical means and common knowledge should all fall within the protection scope of claims 1-3. For example, replacing "ferric chloride colorimetric agent" with "FeCl3" or "ferric ion colorimetric agent" while keeping other technical features unchanged still falls within the protection scope of claims 1-3 of this invention.

[0049] Embodiments 1-4 of this invention at least support the protection scope of claims 4-5.

[0050] Regarding the organic peroxides involved in claims 4-5, their application.

[0051] The technical feature "organic peroxide" is derived from the aforementioned explanation and / or the corresponding technical features "organic peroxide polymerization initiator" and "tert-butyl peroxyneodecanate" in Examples 1-4, which are summarized by the common feature "a class of organic compounds containing an organic peroxide group (-OO-) in the molecule". Therefore, those skilled in the art can reasonably presume that the technical feature "organic peroxide", its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "organic peroxide" based on the existing level of technology and within the scope of conventional technical means and common knowledge should all fall within the protection scope of claims 4-5.

[0052] The technical feature "application" is summarized from the foregoing explanation and / or the corresponding technical feature in Examples 1-4, namely, "a method for preparing hydroxamic acid (R-CONHOH) by reacting acyl chloride with hydroxylamine hydrochloride under alkaline conditions, and quantitatively identifying the product using a ferric chloride colorimetric reaction. During the reaction with the organic peroxidation initiator, the acyl chloride is gradually consumed and its content decreases, reaching the reaction endpoint when the acyl chloride is completely reacted. By reacting different concentrations of acyl chloride with hydroxylamine hydrochloride, the remaining amount of acyl chloride is determined, and the reaction endpoint is accurately determined." Therefore, those skilled in the art can reasonably presume that the technical feature "application," its subordinate concepts, its substantially equivalent technical means, and technical means that can replace it within the scope of conventional technical means and common knowledge based on the existing level of technology should all fall within the protection scope of claims 4-5.

[0053] Embodiments 1-4 of this invention at least support the protection scope of claims 6-10.

[0054] For claims 6-10: absorbance, acyl chloride standard curve.

[0055] The technical feature "absorbance" is derived from the aforementioned explanation and / or the corresponding technical feature in Examples 1-4, such as "the instrument for measuring absorbance is at least one of ultraviolet spectrophotometer, ultraviolet-visible spectrophotometer, visible spectrophotometer, and fully automatic spectrophotometer," through the common feature "optical density, which is the degree to which a substance absorbs light of a specific wavelength." Therefore, those skilled in the art can reasonably presume that the technical feature "absorbance," its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "absorbance" based on existing technology and conventional technical means and common knowledge, should all fall within the protection scope of claims 6-10.

[0056] The technical feature "acyl chloride standard curve" is derived from the foregoing explanation and / or the corresponding technical feature in Examples 1-4, such as "the horizontal axis of the acyl chloride standard curve represents the acyl chloride concentration, and the vertical axis represents the absorbance value." Therefore, those skilled in the art can reasonably infer that the technical feature "acyl chloride standard curve," its subordinate concepts, its substantially equivalent technical means, and technical means that can replace "acyl chloride standard curve" based on existing technology and conventional technical means and common knowledge should all fall within the protection scope of claims 6-10.

[0057] The beneficial effects of this invention are as follows: The present invention has at least the following beneficial effects: 1. Compared with the existing technology, the present invention has better technical effect in terms of detection time.

[0058] According to experimental tests, the present invention reduces the detection time from 25 minutes in the prior art to less than 5 minutes.

[0059] 2. Compared with the prior art, the present invention provides a technical solution with a different technical concept, and its technical effect is equivalent to or slightly improved with the prior art. The differences between the technical concept of the present invention and the prior art include, but are not limited to, "reaction can occur at room temperature", "shorter reaction time, 1-5 minutes", and "reaction progress can be judged by visual inspection".

[0060] Furthermore, based on the present invention: 1. Based on the comparison of Examples 1-4 and Comparative Examples 1-3, the present invention adopts a combination of technical means such as "room temperature reaction of acyl chloride and hydroxylamine reagents" and "visual inspection method" to achieve new technical effects such as "improved accuracy and shortened detection time". The combined technical effect is superior to the sum of the effects of each individual technical means.

[0061] 2. Based on the comparison of Examples 1-4 and Comparative Example 3, the present invention intentionally selects a narrow range of "acyl chloride concentration of 0-30%" which is not mentioned in the prior art from the wide range of "acyl chloride concentration of 0-100%" disclosed in the prior art, and achieves unexpected technical effects such as "improving test accuracy".

[0062] 3. Based on the comparison of Examples 2-4 and Comparative Example 1, the present invention improves upon the existing technology for determining the endpoint of organic peroxide initiators. It enables rapid determination of the reaction endpoint, avoiding the risk of reduced content due to the decomposition of organic peroxides caused by excessively long endpoint monitoring time. The detection time is significantly shorter than that of traditional iodometric and chromatographic methods, enabling rapid endpoint detection. Attached Figure Description

[0063] Figure 1The standard colorimetric tube color chart used as a semi-quantitative reference in Example 1 (where, from right to left, the standard colorimetric tube colors are 0% (w / v), 5% (w / v), 10% (w / v), 20% (w / v), and 30% (w / v)).

[0064] Figure 2 The standard colorimetric tube color chart is the reference standard for semi-quantitative analysis in Example 2 (where, from right to left, the standard colorimetric tube colors are 0% (w / v), 1% (w / v), 2% (w / v), 3% (w / v), 4% (w / v), and 5% (w / v) standard solutions). Detailed Implementation

[0065] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0066] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all instruments, devices, equipment, reagents, products, etc., used in the embodiments of the present invention are obtained through conventional commercial means.

[0067] Specific raw material information is shown in Table 1: Table 1. Raw Material Information

[0068] Example 1 The establishment of a standard curve and its quantitative detection in the production of tert-butyl peroxynedecanoate: A standard curve for neodecanoyl chloride was established and used to quantitatively detect the residual neodecanoyl chloride content at the end of the synthesis reaction of tert-butyl peroxynedecanoate.

[0069] (1) Preparation of reagents and solutions Solution ① (Neodecanoyl chloride standard solution): Accurately weigh 0%, 5%, 10%, 20%, and 30% neodecanoyl chloride, dissolve them in isopropanol, and dilute to 100 mL in colorimetric tubes to obtain standard solutions with concentration gradients of 0%, 5%, 10%, 20%, and 30% (w / v). (This standard curve can be used for standard curves of tert-butyl peroxynedecanoate, cumyl peroxynedecanoate, 1,1,3,3-tetramethylbutyl peroxynedecanoate, and tert-amyl peroxynedecanoate.) This curve can be used for quantitative and semi-quantitative analysis (colorimetric) of high-concentration reaction processes. Solution ② (Alkaline hydroxylamine hydrochloride solution): Weigh 40g of hydroxylamine hydrochloride, dissolve it in deionized water, add 10% sodium hydroxide solution to adjust the pH to 12.0, and finally make up to 100mL.

[0070] Solution ③ (ferric chloride colorimetric solution): Weigh 1% ferric chloride (FeCl3·6H2O), dissolve it in 5% hydrochloric acid solution and make up to 100mL.

[0071] (2) Establishment of standard curve Pipette 10.0 mL of each of the above concentrations ① into five 100 mL colorimetric tubes. Add 10 mL of solution ② to each colorimetric tube and mix. Incubate at room temperature for 3 minutes. Then pipette 2.0 mL of solution ③, dilute to the mark with deionized water, and mix well. Use a UV-Vis spectrophotometer to measure the absorbance of each solution at a wavelength of 525 nm. Plot a standard curve with neodecanoyl chloride concentration on the x-axis and absorbance on the y-axis to obtain the linear regression equation: Y = 0.0452X + 0.005 (R 2 = 0.9995).

[0072] Record the colors of different colorimetric tubes; these colors serve as a semi-quantitative reference (see...). Figure 1 ).

[0073] (3) Sample testing In the synthesis of tert-butyl peroxydecanoate, samples were taken from the dropwise reaction of tert-butyl hydroperoxide and neodecanoyl chloride for 90 min and 120 min, allowed to stand for separation, and 10 mL of the oil phase was pipetted into a 100 mL colorimetric tube. Subsequent operations were identical to the "Standard Curve Establishment" procedure: 10 mL of solution ② was added, the reaction was allowed to proceed for 3 minutes, 2.0 mL of solution ③ was added, and the volume was adjusted to a final volume. The absorbance was then measured.

[0074] Simultaneously record the color and compare it with the color of a standard colorimetric tube.

[0075] (4) Calculation of results Substituting the measured absorbance values ​​of the samples into the linear regression equation of the standard curve, the concentration of neodecanoyl chloride was calculated to be 12.72% (w / v) in the sample at 90 min and 5.38% (w / v) in the sample at 120 min.

[0076] By comparing the sample color with that of a standard colorimetric tube, the sample content can be measured to be between 10% and 20% (w / v) after 90 minutes and between 5% and 10% (w / v) after 120 minutes. This allows for a quick determination that the reaction has not yet ended.

[0077] Example 2 Compared to Example 1, the only difference is that "0%, 1%, 2%, 3%, 4%, and 5% neodecanoyl chloride were accurately weighed, dissolved in isopropanol, and diluted to 100 mL in colorimetric tubes to obtain standard solutions with concentration gradients of 0%, 1%, 2%, 3%, 4%, and 5% (w / v). For sample testing, samples were taken at reaction times of 150 min, 160 min, 170 min, and 180 min." All other steps are the same as in Example 1.

[0078] Results: Plotting the standard curve yielded the linear regression equation: Y = 0.0450X + 0.005 (R²) 2 = 0.9995).

[0079] Record the colors of different colorimetric tubes; these colors serve as a semi-quantitative reference (see...). Figure 2 ).

[0080] Sample testing: The test results showed that the concentrations of the samples after 150 min, 160 min, 170 min, and 180 min were 3.22%, 1.05%, 0.09%, and 0.00% (w / v), respectively. This indicates that the reaction essentially reaches its endpoint within the 170-180 min range and can be terminated.

[0081] Colorimetric analysis can determine the sample concentrations at 150 min, 160 min, 170 min, and 180 min as 3%-4%, 1%-2%, 0%-1%, and 0%, respectively.

[0082] This method allows for rapid on-site sampling and detection, identifying acyl chloride residues by color and determining the endpoint. Hydroxylamine hydrochloride ① and ferric chloride solution ③ can be prepared in advance, and the test takes approximately 5 minutes.

[0083] Example 3 Semi-quantitative rapid determination in the production of di(2-ethylhexyl) peroxide dicarbonate aims to quickly determine the reaction endpoint. In the production of di(2-ethylhexyl) peroxide dicarbonate, the visual comparison method using colorimetric tubes is employed to rapidly determine the reaction endpoint.

[0084] Compared with Example 1, the only difference is that "the acyl chloride is 2-ethylhexyl chloroformate; solution ① (2-ethylhexyl chloroformate standard solution). The concentrations of the standard solutions are 0% (w / v), 1% (w / v), 2% (w / v), 3% (w / v), 4% (w / v), 5% (w / v), 10% (w / v), 20% (w / v), and 30% (w / v), and the corresponding standard curves are 0% (w / v), 1% (w / v), 2% (w / v), 3% (w / v), 4% (w / v), 5% (w / v), 10% (w / v), 20% (w / v), and 30% (w / v)." All other steps are the same.

[0085] In the production of di(2-ethylhexyl) peroxide dicarbonate, after the addition of 2-ethylhexyl chloroformate, samples were taken every 10 minutes for analysis. The residual amount of 2-ethylhexyl chloroformate (acyl chloride) was determined by comparing it with a standard colorimetric tube using a colorimetric method, thus determining the termination of the reaction. The reaction results are shown in the table below.

[0086] Table 2. Residues of 2-Ethylhexyl Chloroformate

[0087] Results Interpretation: Based on this semi-quantitative assessment, the residual 2-ethylhexyl chloroformate content in the reaction solution was greater than 30% in the first 60 minutes, indicating a significant amount of 2-ethylhexyl chloroformate residue. After 70 minutes, the 2-ethylhexyl chloroformate content gradually decreased, and the reaction essentially terminated after 110 minutes, with the content less than 1%, thus the reaction endpoint was determined to have been reached. This method enables rapid and efficient judgment on the production site. A single sample can be tested in approximately 5 minutes.

[0088] Example 4 Compared with Example 1, the only difference is that "30g of hydroxylamine hydrochloride was weighed, dissolved in deionized water, and the pH was adjusted to 11.0 by adding 30% sodium carbonate solution, and finally the volume was adjusted to 100mL". All other steps are the same.

[0089] The resulting equation is: Y = 0.0454X + 0.005 (R) 2 = 0.9995), the obtained standard curve is basically the same as that of Example 1. The concentration of neodecanoyl chloride was measured at 12.73% (w / v) for 90 min and 5.39% (w / v) for 120 min.

[0090] The colorimetric calibration curve is consistent with that of the sample and Example 1.

[0091] Comparative Example 1 According to the synthesis conditions in the prior art patent publication number CN120647564A, the temperature was controlled at 25℃, and 90%–98% (w / w) of neodecanoyl chloride was added dropwise at a rate of 1 mL / min over a period of 45 min. After the addition was complete, the reaction was stirred for another 0.5–3 h. The residual neodecanoyl chloride was checked using the standard curves and detection methods of Examples 1 and 2. Simultaneously, the active oxygen in the oil phase was determined using the group standard T / CPCIF 0094—2021 to determine the reaction endpoint. The reaction results are shown in Table 3 below.

[0092] The standard solution concentrations were 0%, 1%, 2%, 3%, 4%, 5%, 10%, 20%, and 30%, and the corresponding standard curves were 0%, 1%, 2%, 3%, 4%, 5%, 10%, 20%, and 30%. Y = 0.0451X + 0.005 (R 2 = 0.9995).

[0093] Table 3. Comparison of Reaction Results

[0094] As shown in the table above, spectrophotometry can accurately quantify acyl chloride residues, with a detection time of approximately 15 minutes. Colorimetry allows for rapid on-site detection, taking only 5 minutes. The results indicate that the reaction essentially reaches its endpoint at 140 minutes, with neodecanoyl chloride residues being less than 1%. The reaction can be terminated quickly.

[0095] The iodometric method for content determination utilizes the oxidation of iodide ions by peroxides to form elemental iodine, which is then quantitatively titrated with sodium thiosulfate. Data shows that the content gradually decreases after 150 minutes, and the inflection point can be used to determine the reaction endpoint. However, in the coulometric method, iodide ions can react with either tert-butyl peroxyneodecanate or the reactant tert-butyl hydrogen peroxide. Incompletely reacted tert-butyl hydrogen peroxide affects the final content determination. Since the molecular weight of tert-butyl hydrogen peroxide is smaller than that of tert-butyl peroxyneodecanate, the result calculated based on tert-butyl peroxyneodecanate will exceed 100%. After 140 minutes, the tert-butyl peroxyneodecanate content gradually decreases with increasing reaction time, mainly due to the decomposition of tert-butyl peroxyneodecanate. The determination time for a single sample is 65 minutes. This long determination time makes it difficult to definitively determine the reaction endpoint.

[0096] Comparative Example 2 Solution ② (alkaline hydroxylamine hydrochloride solution) in Example 1: Weigh 40g of hydroxylamine hydrochloride, dissolve in deionized water, adjust the pH to 12.0 with 10% sodium hydroxide solution, and finally bring the volume to 100mL. Modified to Solution ② (alkaline hydroxylamine hydrochloride solution): Weigh 10g of hydroxylamine hydrochloride, dissolve in deionized water, adjust the pH to 12.0 with 10% sodium hydroxide solution, and finally bring the volume to 100mL.

[0097] The obtained standard curve is as follows: Plotting the concentration of neodecanoyl chloride on the x-axis and the absorbance value on the y-axis, the linear regression equation is obtained: Y = 0.0252X + 0.005 (R² + π / 2)². 2 = 0.6895). The linear correlation of the curve decreased significantly, and the test was inaccurate at high concentrations.

[0098] Comparative Example 3 According to the synthesis conditions in the existing technical literature "Spectrophotometric Determination of Isononanoyl Chloride and Pteropentanoyl Chloride", isononanoyl chloride reacts with hydroxylamine reagent at a reflux temperature of 72℃ for 15 min to generate hydroxamic acid. Hydroxamic acid and ferric ions are adjusted to pH=1-2 to form a complex and produce color. The complex has maximum absorption of visible light at 550nm, thus determining the reaction endpoint.

[0099] Using this method in the production of diisobutyryl peroxide, a sample was taken after the dropwise addition process was completed, and the experiment was conducted according to the literature. During the experiment, violent decomposition occurred, producing a large number of bubbles. The hydroxylamine reagent was decomposed by the free radicals generated by the decomposition of organic peroxides, and no color development was possible.

[0100] Verification of technical effectiveness and / or analysis of technical problem solving This invention discloses a method for preparing hydroxamic acid (R-CONHOH) by reacting acyl chloride with hydroxylamine hydrochloride under alkaline conditions, and for quantitative identification of the product using a ferric chloride colorimetric reaction. The acid produced in the reaction is neutralized by excess alkali, driving the reaction to completion. This reaction is extremely fast, and the color of the product is directly proportional to the acyl chloride content, requiring only a short testing time and exhibiting high accuracy.

[0101] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A rapid detection method for the reaction endpoint of organic peroxides, comprising the following steps: (1) Constructing the standard color gradient of acyl chloride: S1. Acyl chloride solution: Dissolve acyl chloride in solvent to obtain a series of acyl chloride solutions with acyl chloride content of 0 w / v% - 30 w / v%, wherein, The solvent is at least one of ethanol and isopropanol; S2. Alkaline hydroxylamine hydrochloride solution: Dissolve hydroxylamine hydrochloride in a solvent, add an alkaline substance to obtain an alkaline hydroxylamine hydrochloride solution with a concentration of 30w / v%-50w / v%. S3. Mix the series of acyl chloride solutions obtained in S1 and the alkaline hydroxylamine hydrochloride solution obtained in S2 in equal volumes, and then react them with ferric chloride colorimetric reagent to obtain the standard color gradient of acyl chloride. (2) Sample detection: Mix the sample from the organic peroxide reaction process with an equal volume of the acyl chloride solution described in step (1) and an equal volume of alkaline hydroxylamine hydrochloride solution, and then react with ferric chloride colorimetric reagent to obtain the sample test sample; The organic peroxide is one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate. In step (2), the amount of ferric chloride colorimetric reagent added is the same as that added in step (1); (3) Result determination: Visually compare the color of the sample test sample obtained in step (2) with the color gradient of the acyl chloride standard in step (1) to determine the remaining acyl chloride content.

2. The rapid detection method according to claim 1, characterized in that, The acyl chloride in S1 is one of 2-ethylhexyl chloroformate, neodecanoyl chloride, tervapotranyl chloride, and isonononyl chloride; preferably one of 2-ethylhexyl chloroformate and neodecanoyl chloride; more preferably neodecanoyl chloride; Preferably, the solvent for the acyl chloride solution in S1 is isopropanol; The acyl chloride concentration of the acyl chloride solution described in S1 is 0 w / v%-30 w / v%. The solvent for the alkaline hydroxylamine hydrochloride solution in S2 is at least one of water, methanol, ethanol, and isopropanol; preferably water; more preferably at least one of deionized water, purified water, ultrapure water, and drinking water; and even more preferably deionized water. The alkaline substance in the alkaline hydroxylamine hydrochloride solution described in S2 is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, and pyridine; preferably at least one of sodium hydroxide, sodium bicarbonate, and sodium carbonate; more preferably sodium hydroxide; and even more preferably 6% sodium hydroxide. Preferably, the concentration of hydroxylamine hydrochloride in S2 is 30 w / v%-40 w / v%; more preferably 40 w / v%. Preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is in the range of 10-13; more preferably, it is 12.

3. The rapid detection method according to claim 1, characterized in that, The solvent for the ferric chloride colorimetric reagent described in S3 is an acidic solvent; preferably at least one of hydrochloric acid and sulfuric acid. Preferably, the concentration of the acidic solvent is 3wt%-10wt%; more preferably 5wt%; The concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 0.1wt%-2wt%; preferably 1wt%. The reaction conditions described in S3 are: reaction at room temperature for 1-5 minutes; preferably: reaction at room temperature for 3 minutes. The volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 5-30:5-30:1-5; preferably 10:10:

2. Preferably, the container for reacting with the ferric chloride colorimetric reagent in step S3 is at least one of a volumetric flask and a colorimetric tube; more preferably, it is a colorimetric tube; even more preferably, it is a 100mL colorimetric tube. In step (2), the container that reacts with the ferric chloride colorimetric reagent is at least one of a volumetric flask and a colorimetric tube; preferably a colorimetric tube; more preferably a 100mL colorimetric tube.

4. The application of the rapid detection method according to any one of claims 1-3 in organic peroxide reactions.

5. Use according to claim 4, characterized in that, The organic peroxide is an organic peroxide-based polymerization initiator; Preferably, the organic peroxide polymerization initiator is selected from one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate.

6. A rapid detection method for the reaction endpoint of organic peroxides, comprising the following steps: (1) Constructing the standard color gradient of acyl chloride: S1. Acyl chloride solution: Acyl chloride is dissolved in a solvent to obtain a series of acyl chloride solutions with an acyl chloride content of 0 w / v% to 30 w / v%, wherein, The solvent is at least one of ethanol and isopropanol; S2. Alkaline hydroxylamine hydrochloride solution: Dissolve hydroxylamine hydrochloride in a solvent, add an alkaline substance to obtain an alkaline hydroxylamine hydrochloride solution with a concentration of 30w / v%-50w / v%. S3. Mix the series of acyl chloride solutions obtained in S1 with the alkaline hydroxylamine hydrochloride solution obtained in S2 in equal volumes, and then react them with ferric chloride colorimetric reagent to obtain a series of standard reaction solutions. S4. Measure the absorbance of the series of standard reaction solutions obtained in S3 to establish a standard curve for acyl chloride; (2) Sample detection: Mix the sample from the organic peroxide reaction process with an equal volume of the acyl chloride solution described in step (1) and an equal volume of alkaline hydroxylamine hydrochloride solution, and then react with ferric chloride colorimetric reagent to obtain the sample test sample; The organic peroxide is one of the following: tert-butyl peroxyneodecanate, cumyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-amyl peroxyneodecanate, 1,1,3,3-tetramethylbutyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneodecanate, tert-butyl peroxyneonanoate, tert-amyl peroxyacetate, and di(2-ethylhexyl) peroxydicarbonate. In step (2), the amount of ferric chloride colorimetric reagent added is the same as that added in step (1); (3) Result determination: The absorbance of the sample obtained in step (2) is measured, and the acyl chloride content is accurately calculated using the acyl chloride standard curve established in step (1).

7. The rapid detection method according to claim 6, characterized in that, The acyl chloride in S1 is one of 2-ethylhexyl chloroformate, neodecanoyl chloride, tervaline chloride, and isonononoyl chloride; Preferably, the solvent for the acyl chloride solution in S1 is isopropanol; The acyl chloride concentration of the acyl chloride solution described in S1 is 0 w / v%-30 w / v%. The solvent for the alkaline hydroxylamine hydrochloride solution described in S2 is at least one of water, methanol, ethanol, and isopropanol; The alkaline substance in the alkaline hydroxylamine hydrochloride solution described in S2 is at least one of sodium hydroxide, sodium bicarbonate, sodium carbonate, and pyridine; preferably at least one of sodium hydroxide, sodium bicarbonate, and sodium carbonate; more preferably sodium bicarbonate; and even more preferably 6% sodium bicarbonate. Preferably, the concentration of hydroxylamine hydrochloride in S2 is 30w / v%-40w / v%; more preferably, the concentration of hydroxylamine hydrochloride in S2 is 40w / v%. Preferably, the pH value of the alkaline hydroxylamine hydrochloride solution obtained in S2 is in the range of 10-13; more preferably, it is 12.

8. The rapid detection method according to claim 6, characterized in that, The solvent for the ferric chloride colorimetric reagent described in S3 is an acidic solvent; preferably at least one of hydrochloric acid and sulfuric acid; more preferably hydrochloric acid. Preferably, the concentration of the acidic solvent is 3wt%-10wt%; more preferably 5wt%; The concentration of ferric chloride in the ferric chloride colorimetric reagent described in S3 is 0.1wt%-2wt%; preferably 1wt%. The reaction conditions described in S3 are: reaction at room temperature for 1-5 minutes; preferably: reaction at room temperature for 3 minutes. The volume ratio of the acyl chloride solution, alkaline hydroxylamine hydrochloride solution, and ferric chloride colorimetric reagent in S3 is 5-30:5-30:1-5; preferably 10:10:

2.

9. The rapid detection method according to claim 6, characterized in that, In step S3, the container that reacts with the ferric chloride colorimetric reagent is at least one of a volumetric flask and a colorimetric tube; more preferably, a colorimetric tube; and even more preferably, a 100mL colorimetric tube. Preferably, step S3, after reacting with the ferric chloride colorimetric reagent, further includes a step of diluting the solution to the mark on the container with a solvent; more preferably, the solvent used for dilution is water; even more preferably, the solvent used for dilution is selected from at least one of deionized water, purified water, ultrapure water, and drinking water; most preferably, the solvent used for dilution is deionized water. The absorbance measuring instrument mentioned in S4 is at least one of ultraviolet spectrophotometer, ultraviolet-visible spectrophotometer, visible spectrophotometer, and fully automatic spectrophotometer; preferably at least one of ultraviolet spectrophotometer and ultraviolet-visible spectrophotometer; more preferably ultraviolet-visible spectrophotometer. Preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 500-550 nm; more preferably 520-530 nm; and even more preferably 525 nm. Preferably, the x-axis of the acyl chloride standard curve in S4 represents the acyl chloride concentration, and the y-axis represents the absorbance value.

10. The rapid detection method according to claim 6, characterized in that, In step (2), the container that reacts with the ferric chloride colorimetric reagent is at least one of a volumetric flask and a colorimetric tube; preferably a colorimetric tube; more preferably a 100mL colorimetric tube; Preferably, step (2) further includes a step of diluting the solution to the mark on the container with a solvent after reacting with the ferric chloride colorimetric agent; The absorbance measuring instrument in step (3) is at least one of ultraviolet spectrophotometer, ultraviolet-visible spectrophotometer, visible spectrophotometer, and fully automatic spectrophotometer; preferably at least one of ultraviolet spectrophotometer and ultraviolet-visible spectrophotometer; more preferably ultraviolet-visible spectrophotometer. Preferably, the wavelength range of the ultraviolet-visible spectrophotometer is 500-550 nm; more preferably 520-530 nm; and even more preferably 525 nm.

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