CN109999716B

CN109999716B - A kind of nonionic fluorine-containing surfactant and its preparation method and application

Info

Publication number: CN109999716B
Application number: CN201910251324.5A
Authority: CN
Inventors: 程德书; 罗菊香; 李奇勇; 肖旺钏; 张家坤
Original assignee: Sanming University
Current assignee: Jin Zhuzhong
Priority date: 2019-03-29
Filing date: 2019-03-29
Publication date: 2021-04-27
Anticipated expiration: 2039-03-29
Also published as: CN109999716A

Abstract

本发明提供了一种非离子含氟化合物及其制备方法和应用，属于含氟新材料领域。一种非离子型含氟表面活性剂，其结构如通式(Ⅰ)所示：

该活性剂不含类PFOA物质，是一种环保的、价格便宜的非离子型含氟基材润湿剂。且能够在水下涂料中用作基材润湿剂，且润湿效果好。一种非离子型含氟表面活性剂的制备方法，其制备简易、环保，可实现连续生产。The invention provides a nonionic fluorine-containing compound, a preparation method and application thereof, and belongs to the field of new fluorine-containing materials. A non-ionic fluorosurfactant whose structure is shown in the general formula (I):

The active agent does not contain PFOA-like substances, and is an environmentally friendly and inexpensive non-ionic wetting agent for fluorine-containing substrates. And can be used as a substrate wetting agent in underwater coatings, and the wetting effect is good. The invention discloses a method for preparing a nonionic fluorine-containing surfactant, which is simple and environmentally friendly, and can realize continuous production.

Description

Nonionic fluorine-containing surfactant and preparation method and application thereof

Technical Field

The invention relates to a nonionic fluorine-containing compound and a preparation method and application thereof, belonging to the field of novel fluorine-containing materials.

Background

Wettability refers to the tendency of a fluid to spread or adsorb on a solid surface in the presence of immiscible phase fluids. The coating should be capable of completely wetting the substrate when applied in order to obtain a smooth, defect-free surface. In solvent-based coatings, there is substantially no problem of wetting of the substrate due to the low surface tension of the solvent, and water-based coatings are widely used with increasing global attention to environmental issues. And the surface tension of water is 72.75X 10^-3N·m^-1And is greater than the surface tension of a common substrate, which causes a problem of difficulty in wetting.

Substrate wetting agents for aqueous coatings based on heptamethyltrisiloxane polyethers are known which significantly reduce the surface tension of water to 21mN/m and have the advantages of good wetting, strong adhesion, excellent spreadability, high pore permeability and good rain wash resistance. However, such wetting agents are susceptible to hydrolysis under acidic or alkaline conditions, which limits their use under certain conditions; in some systems, the surface tension needs to be reduced to 20mN/m, so that the common organosilicon system is difficult to meet the requirement.

The fluorocarbon surfactant is obtained by substituting all or part of the hydrogen atoms in the hydrocarbon chain of the hydrocarbon surfactant with fluorine atoms. Since fluorine is the most electronegative element, the bond energy of the fluorocarbon bond is high. In addition, the fluorine atom has a larger atomic radius than the hydrogen atom and effectively protects the perfluorinated C-C bond, so that it has unique properties such as high stability and low surface tension, and can reduce the surface tension to even 17 to 18mN/m, which is very good as a substrate wetting agent in an underwater paint. The existing fluorine-containing wetting agents such as 3M fluorocarbon surfactant FC-4430 and DuPont FS-63 anion fluorine-containing wetting agents are quite expensive, and the price of the fluorine-containing wetting agents is more than 1000 yuan/kg.

In the prior patents, nonionic fluorosurfactants have also received much attention. For example, chinese patent application No. 201080039806.1 discloses the use of a reactant of a fluoro-C6 epoxide with two terminal hydroxyl-type polyethylene glycol to prepare a nonionic fluoro-surfactant for use as a dehazing agent; application No. 201210344043.2 discloses that perfluoroalkyl sulfonyl fluoride and N, N '-dimethyl (ethyl) -1, 3-propane diamine are subjected to amidation reaction to obtain an intermediate 1, the intermediate is refined and then reacts with ethylene oxide or chloroethanol by taking acetone as a solvent to obtain an intermediate 2 (N' -3- (dimethyl (ethyl)) -propyl- (N-perfluorobutylsulfonyl-N-epoxy) -amine) and an intermediate 2, and the intermediate and ethylene oxide are subjected to ring-opening reaction according to different proportions to obtain a nonionic fluorine-containing surfactant; the invention patent application No. 201710034468.6 discloses a process for preparing nonionic surfactants by reacting perfluoroalkyl iodides with vinyl or allyl polyoxyethylene ethers.

In these prior patents, the fluorine-containing raw material is expensive, the preparation method is complicated, and the development of a cheap and easily synthesized nonionic surfactant is urgently needed in the market. Octafluoroisobutylene is a colorless, slightly grassy toxic gas. Perfluoroisobutylene is generated as a byproduct in the production of tetrafluoroethylene and hexafluoropropylene through a pyrolysis method, and the treatment is quite difficult. The early treatment method is to bury or fill the residual liquid containing perfluoroisobutylene in a steel cylinder and sink it into the open sea, but cannot solve the fundamental problem. The most thorough and simple practice is direct incineration, but if perfluoroisobutylene leaks, the danger is great. It is now common practice in the industry to absorb perfluoroisobutylene with a lower alcohol (usually methanol) and add to the moderately toxic fluoroether. The common treatment method for the fluoroether is to burn the fluoroether to generate carbon dioxide and hydrogen fluoride, then the carbon dioxide and the hydrogen fluoride are absorbed by lime water to generate calcium fluoride, and the treated flue gas is discharged at high altitude. This is certainly a huge waste from the perspective of resource utilization, and the waste gas and slag generated after treatment also pollute the environment. Therefore, how to comprehensively utilize octafluoroisobutylene is a common problem in the fluorine chemical industry.

The octafluoroisobutylene is used as a fluorine carbon source to develop the nonionic fluorine-containing surfactant, so that the bottleneck of limiting the production of hexafluorobutene can be solved, and the fluorine-containing base material wetting agent with low cost can be provided for the water-based paint. The fluorine-containing surfactant taking octafluoroisobutylene as a fluorine carbon source is environment-friendly, and does not have the problem of persistent toxicity of C8 fluorine-containing surfactants, so that the method not only has extremely high technical and economic values, but also is beneficial to the development of the material industry in China.

Disclosure of Invention

The first purpose of the invention is to provide a non-ionic fluorine-containing surfactant which does not contain PFOA-like substances, is an environment-friendly and cheap non-ionic fluorine-containing base material wetting agent and has good wetting agent effect.

The second purpose of the invention is to provide a preparation method of the nonionic fluorine-containing surfactant, which is simple and environment-friendly in preparation and can realize continuous production.

The third purpose of the invention is to provide a nonionic fluorine-containing surfactant used as a substrate wetting agent in underwater paint.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

a nonionic fluorine-containing surfactant has a structure shown in a general formula (I):

（Ⅰ）

R¹is a formula (C)_mH_2mO-）_sR³Where m is a number greater than or equal to 2.0 and not greater than 2.5, s is a number from 6 to 30, and R³Is an alkyl group of 1 to 4 carbon atoms or an acetyl group, R¹Can be represented as (C)₃H₆O)_P(C₂H₄O)_qR³Wherein ethylene oxide and propylene oxide may be randomly copolymerized or block copolymerized, wherein P is a number from 0 to 10, q is a number from 6 to 20, and at least 60 mol% of the oxyalkylene groups are oxyethylene groups.

A method of making a nonionic fluorosurfactant comprising: the polyether with primary hydroxyl and the octafluoroisobutylene are subjected to addition reaction, and the chemical structural formula of the octafluoroisobutylene is represented by (II):

（Ⅱ）

the molar ratio of the primary hydroxyl polyether to the octafluoroisobutylene is 1.1:1-1.05: 1.

A non-ionic fluorine-containing surfactant used as a wetting agent is applied to water-based paint and ink.

The nonionic fluorine-containing compound provided by the invention and the preparation method and the application thereof have the beneficial effects that:

a non-ionic fluorine-containing surfactant does not contain PFOA-like substances, and is an environment-friendly and low-price non-ionic fluorine-containing base material wetting agent. And can be used as a substrate wetting agent in underwater coatings, and the wetting effect is good.

The preparation method of the nonionic fluorine-containing surfactant is simple and easy to prepare, environment-friendly and capable of realizing continuous production.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below.¹The H NMR spectrum is obtained by testing a Bruker 400 MHz nuclear magnetic resonance instrument, deuterated chloroform is used as a solvent, and Tetramethylsilane (TMS) is used as an internal standard. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following is a detailed description of a nonionic fluorosurfactant of the embodiments of the invention, its preparation method and use.

（Ⅰ）

Further, the nonionic fluorine-containing surfactant, R³Is methyl. As the hydrophilic end, a methoxy group is more hydrophilic than a longer alkyl chain such as an ethoxy group or a butoxy group.

Further, the nonionic fluorosurfactant, the P is 1 to 3, and polypropylene oxide is hydrophobic, and if P is too large, its solubility in water is affected.

Said nonionic fluorosurfactant and said q is a number from 8 to 18. Polyethylene oxide is added to the fluorosurfactant to increase its water solubility, and if q is too small, the water solubility is too poor, and too large results in low fluorine content and a reduced ability to lower the surface tension of the system.

At least 80 mol% of the oxyalkylene groups of the nonionic fluorine-containing surfactant are oxyethylene groups, so that the prepared fluorine-containing surfactant has good surface activity.

The invention also provides a preparation method of the nonionic fluorine-containing surfactant, which comprises the following steps: polyether with primary hydroxyl and octafluoroisobutylene are subjected to addition reaction under the conditions of weak acidity or neutrality, solvent or no solvent at a certain temperature to obtain the octafluoroisobutylene. The chemical structural formula of the octafluoroisobutylene is represented by (II):

（Ⅱ）

preparation of primary hydroxyl polyethers is known and includes some commercial products such as MPEG350 (methoxy terminated, molecular weight 350), MPEG400 (methoxy terminated, molecular weight 400), MPEG600 (methoxy terminated, molecular weight 600), MPEG750 (methoxy terminated, molecular weight 750), and the like.

The octafluoroisobutylene contains two trifluoromethyl groups on one carbon of an olefinic bond, and the trifluoromethyl group has a strong electron-withdrawing effect, so that the octafluoroisobutylene and hydroxyl, amino, sulfydryl and other groups can easily perform electrophilic addition and substitution reaction.

The common fluorine carbon source of the fluorine-containing surfactant is fluorine alkyl iodide, or fluoroalcohol, fluoroether, perfluorosulfonyl fluoride and the like, which are expensive and complex in preparation process, and finally, the fluorine-containing surfactant is expensive, so that the large-scale application of the fluorine-containing surfactant is limited. In the embodiment, because pure octafluoroisobutylene is used and PFOA-like substances are not contained, the non-ionic fluorine-containing base material wetting agent is environment-friendly and low in price. The method for treating the byproduct octafluoroisobutylene which is difficult to treat changes waste into valuable and promotes the healthy development of the fluorine chemical industry.

Further, the catalyst is obtained by adding polyether with primary hydroxyl and octafluoroisobutylene under the weak acidic condition, and the used acid catalyst is acetic acid, p-toluenesulfonic acid, trifluoroacetic acid and sulfamic acid. It is known from The literature (Zeifman Y V, Ter-Gabrilyon E G, Gambaryan N P, et al, The chemistry of perfluoroisobutene [ J ]. Russian Chemical Reviews, 1984, 53(3): 256-273.) that The reaction of octafluoroisobutylene with a primary hydroxyl group is an addition reaction under neutral or weakly acidic conditions and a substitution reaction under basic conditions. In order to obtain a nonionic fluorosurfactant by addition, this example was conducted under weakly acidic conditions. Acetic acid, p-toluenesulfonic acid, trifluoroacetic acid and sulfamic acid can be added into the system to adjust the acidity of the system; other organic acids, such as methanesulfonic acid, propionic acid, butyric acid, benzoic acid, phthalic acid are also possible. In terms of conversion efficiency, the catalytic efficiency of acetic acid, p-toluenesulfonic acid, trifluoroacetic acid and sulfamic acid is higher.

In this example, the molar ratio of primary hydroxyl polyether to octafluoroisobutylene was 2:1 to 1.05: 1. The primary hydroxyl polyether is safe relative to octafluoroisobutylene and therefore may be in excess of the primary hydroxyl acrylate monomer, thereby allowing the octafluoroisobutylene to react to completion.

Preferably, the molar ratio of the primary hydroxyl polyether to the octafluoroisobutylene is 1.1:1 to 1.05: 1. For economy, the primary hydroxyl polyethers can be controlled in slight excess.

Preferably, the addition temperature of the primary hydroxyl polyether and the octafluoroisobutylene is 20-80 ℃. Reaction temperatures below 20 ℃, such as 10 ℃, are also possible, but the reaction rate is too slow; when the reaction temperature is higher than 80 ℃, side reactions such as substitution reaction may increase, eventually resulting in low yield of the objective product.

In this embodiment, the addition reaction of the primary hydroxyl polyether and octafluoroisobutylene can be carried out in a bulk method or in the presence of a solvent. If solvent is the case, the solvent is selected from solvents which do not react with the two monomers, such as ketones, esters, aromatic hydrocarbons, ethers, and the like. Can be acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, amyl acetate, octyl acetate, toluene, xylene, trimethylbenzene, diethyl ether, propylene glycol methyl ether acetate and other solvents. The addition reaction is preferably carried out in the absence of a solvent.

The nonionic fluorine-containing surfactant can be used as a wetting agent in water-based paint and ink, the addition amount of the nonionic fluorine-containing surfactant can be 0.01-0.5% of the total amount of the formula, and the addition amount can be adjusted according to a substrate and application.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Introducing nitrogen into a pressure reactor, vacuumizing for 3 times, adding 70 g (0.2 mol) of MPEG350, 0.01g of p-toluenesulfonic acid, 38 g (0.19 mol) of octafluoroisobutylene, reacting for 12 hours at 60 ℃, completely reacting the octafluoroisobutylene, introducing nitrogen to remove trace octafluoroisobutylene, absorbing by methanol to obtain 106 g of colorless and transparent liquid, and converting by 98.1%. Chemical structure of the product is as follows¹And H NMR characterization.¹H NMR(400MHz，CDCl₃) ，δ(TMS，ppm)，3.40(3H，-CH ₃)，3.52(32H，-CH ₂ -)， 3.98(1H，=CH-)。

Example 2

Introducing nitrogen into a pressure reactor, vacuumizing for 3 times, adding 80 g (0.2 mol) of MPEG400, 0.003 g of trifluoroacetic acid and 39 g (0.195 mol) of octafluoroisobutylene, reacting for 15 hours at 50 ℃, completely reacting the octafluoroisobutylene, introducing nitrogen to remove trace octafluoroisobutylene, and absorbing with methanol. 111.1 g of a colorless transparent liquid was obtained with a conversion of 93.2%.Chemical structure of the product is as follows¹And H NMR characterization.¹H NMR(400MHz，CDCl₃) ，δ(TMS，ppm)，3.40(3H，-CH ₃)，3.52(36H，-CH ₂ -)， 3.98(1H，=CH-)。

Example 3

Introducing nitrogen into a pressure reactor, vacuumizing for 3 times, adding 120 g (0.2 mol) of MPEG600, 0.01g of p-toluenesulfonic acid, 36 g (0.18 mol) of octafluoroisobutylene, reacting for 18 hours at 40 ℃, completely reacting the octafluoroisobutylene, introducing nitrogen to remove trace octafluoroisobutylene, and absorbing with methanol. 150.1 g of a colorless transparent liquid was obtained with a conversion of 96.1%. Chemical structure of the product is as follows¹And H NMR characterization.¹H NMR(400MHz，CDCl₃) ，δ(TMS，ppm)，3.40(3H，-CH ₃)，3.52(56H，-CH ₂ -)， 3.98(1H，=CH-)。

Example 4

Introducing nitrogen into a pressure reactor, vacuumizing for 3 times, adding 150 g (0.2 mol) of MPEG750, 0.01g of p-toluenesulfonic acid, 39 g (0.195 mol) of octafluoroisobutylene, reacting at 60 ℃ for 18 hours until the octafluoroisobutylene is completely reacted, introducing nitrogen to remove trace octafluoroisobutylene, and absorbing with methanol. 180.1 g of a colorless transparent liquid was obtained with a conversion of 95.1%. Chemical structure of the product is as follows¹And H NMR characterization.¹H NMR(400MHz，CDCl₃) ，δ(TMS，ppm)，3.40(3H，-CH ₃)，3.52(68H，-CH ₂ -)， 3.98(1H，=CH-)。

Examples of the experiments

The nonionic fluorosurfactant aqueous wetting agent provided in examples 1-4 was used for detection by way of spread measurement.

The non-ionic fluorosurfactant (0.1 g) was dissolved in 100 ml of distilled water and the solution (0.05 ml) was placed on a PVC plate by micropipette. The water droplets spread spontaneously due to the low surface tension of the fluorosurfactant and the diameter (in mm) of the wetted area occupied by the spreading of the aqueous solution is a direct measurement of the nonionic fluorosurfactant and the results are shown in table 1.

TABLE 1 spreading of wetting agent on PVC plates

Sample (I)	No surfactant	Example 1	Example 2	Example 3	Example 4	Commercial silicone wetting agents
							Diameter of	8	55	50	45	43	38

From the above test results, the nonionic fluorosurfactant has better wetting performance than commercial surfactants.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

1. A non-ionic fluorosurfactant, characterized in that its structure is shown in the general formula (I):

(I)

R ¹ is a group of formula (C _m H _2m O-) _s R ³ , and R ¹ is specifically represented as (C ₃ H ₆ O) _P (C ₂ H ₄ O) _q R ³ , wherein m is a group greater than or equal to A value of 2.0 and not more than 2.5, s is a value of 6 to 30, and R ³ is an alkyl or acetyl group of 1 to 4 carbon atoms, wherein ethylene oxide and propylene oxide are random copolymerization or block copolymerization , wherein P is a number from 0 to 10, q is a number from 8 to 18, and at least 60 mol % of the oxyalkylene groups are oxyethylene groups.

2 . The nonionic fluorosurfactant according to claim 1 , wherein the R ³ is a methyl group. 3 .

3 . The nonionic fluorosurfactant according to claim 1 , wherein the P is 1 to 3. 4 .

4 . The nonionic fluorosurfactant according to claim 1 , wherein at least 80 mol % of the oxyalkylene groups are oxyethylene groups. 5 .

5. A method for preparing a nonionic fluorosurfactant as claimed in any one of claims 1 to 4, characterized in that it comprises: making the polyether with primary hydroxyl group and octafluoroisobutene pass through an addition reaction Obtained, the chemical structural formula of the octafluoroisobutene is represented by (II):

(II)

The molar ratio of the polyether with primary hydroxyl group and the octafluoroisobutene is 1.1:1-1.05:1.

6 . The method for preparing a nonionic fluorosurfactant according to claim 5 , wherein the polyether having a primary hydroxyl group and the octafluoroisobutylene undergo an addition reaction under weakly acidic conditions. 7 .

7. the preparation method of nonionic fluorine-containing surfactant according to claim 6, is characterized in that, under weak acid condition, used acid catalyst is acetic acid, p-toluenesulfonic acid, trifluoroacetic acid and amino acid any of the sulfonic acids.

8 . The method for preparing a nonionic fluorosurfactant according to claim 5 , wherein the addition temperature of the primary hydroxyl polyether and the octafluoroisobutylene is 20° C. to 80° C. 9 .

9. The nonionic fluorosurfactant of any one of claims 1-4 is used as a wetting agent in water-based paints and inks.