CN109705267B

CN109705267B - Microspherical ionomer with cross-linked structure and preparation method and application thereof

Info

Publication number: CN109705267B
Application number: CN201711010248.6A
Authority: CN
Inventors: 袁浩; 宋文波; 乔金樑; 刘振杰; 毕福勇; 胡慧杰
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2017-10-25
Filing date: 2017-10-25
Publication date: 2021-07-30
Anticipated expiration: 2037-10-25
Also published as: CN109705267A

Abstract

The invention relates to the field of high polymer materials, and discloses a microspherical ionomer with a cross-linked structure and a preparation method thereofPreparation method and application. The ionomer contains a structural unit A represented by formula (1), a structural unit B provided by a mixed olefin, and a crosslinked structure provided by a crosslinking agent, wherein M is₁And M₂Each independently H or a metal cation, the mixed olefins being provided by carbon four and/or carbon five. Also disclosed are methods of making ionomers and ionomers made by the methods, the methods comprising: contacting maleic anhydride, mixed olefin and a crosslinking agent for reaction; the resulting product is salified by reaction with a base in the presence of water. In addition, the invention also discloses application of the ionomer as a nucleating agent in modification of PET. The ionomer obtained by the invention has good nucleation effect on PET, and the preparation process is simple, green and environment-friendly.

Description

Microspherical ionomer with cross-linked structure and preparation method and application thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to a microspherical ionomer with a cross-linked structure and a preparation method and application thereof.

Background

In the field of petrochemical industry in China, abundant carbon four (C4) and carbon five (C5) resources are available, but for technical reasons, the utilization rates of C4 and C5 are low all the time. With the change of petrochemical resource patterns, the C4 and C5 fractions are more and more valuable, and the effective utilization of the C4 and C5 resources is very significant for China with resource shortage.

The ionic polymer is ionomer or ionomer, and is a polymer material with a small amount of ionic groups on a high molecular chain, wherein the molar content of the ionic groups is not more than 15%. The ionomer is a perfect combination of inorganic ions and organic molecules, and due to the introduction of ionic groups, the molecules in the ionomer have special interaction which is not existed in general polymers, such as ion-ion interaction; ion pairs interact with ion pairs; the ion interacts with the dipole; hydrogen bonding interactions, and the like. These specific interactions give ionomers many unique properties and have important applications in polymer modification, functional materials, etc.

In addition, the research on the preparation and application of the polymer microspheres is a hotspot in the field of functional polymer materials, and the polymer microspheres from nano-scale to micron-scale have the special properties of large specific surface area, strong adsorbability, large coacervation effect and strong surface reaction capability, and can be widely applied to many high and new technical fields.

In US 4748196, a free radical polymerization process is described for producing an alpha-olefin/maleic anhydride polymer having a molecular weight of 200 to 3000, wherein isoamylene and maleic anhydride are polymerized under nitrogen protection and stirring, and the mixture is reacted at 80 ℃ for 3 hours to obtain an isoamylene/maleic anhydride polymer.

Zhang Xu, Wang Xiaomei et al in "dicyclopentadiene-maleic anhydride free radical copolymerization" ("petrochemical, 2005, 34 (5): 474-.

However, there is still room for improvement in the nucleation effect of the ionomers prepared by the above methods on PET.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a microspherical ionomer with a cross-linked structure and a preparation method and application thereof.

In order to achieve the above object, the present invention provides, in one aspect, a microspheroidal ionomer having a crosslinked structure, the ionomer comprising a structural unit A represented by formula (1), a structural unit B provided by a mixed olefin, and a crosslinked structure provided by a crosslinking agent,

wherein M is₁And M₂Each independently H or a metal cation, the mixed olefins being provided by carbon four and/or carbon five.

In a second aspect, the present invention provides a method of making an ionomer, the method comprising:

(1) in an organic solvent, in the presence of an initiator, contacting maleic anhydride, a mixed olefin and a crosslinking agent for reaction, wherein the mixed olefin is provided by carbon four and/or carbon five;

(2) salifying the product obtained in step (1) by reacting it with a base in the presence of water.

In a third aspect, the invention provides an ionomer prepared by the method of the second aspect.

In a fourth aspect, the present invention provides the use of the ionomer as a nucleating agent for the modification of polyethylene terephthalate.

The ionomer (or ionomer microsphere) obtained by the method has a cross-linking and microsphere structure, a good nucleation effect on PET, a simple preparation process, and green and environment-friendly effects, and the ionomer microsphere can be obtained by simple separation operation (without using a precipitant) after the reaction is finished. In addition, the invention also effectively realizes the comprehensive utilization of industrial mixed carbon four or mixed carbon five.

Moreover, in a preferred embodiment of the present invention, the ionomer is prepared by a one-pot process, and the suspension after polymerization is directly reacted with alkali without separation and drying, thereby further simplifying the process flow and reducing the energy consumption.

Drawings

FIG. 1 is a graph of the infrared spectrum of an ionomer synthesized according to one embodiment of the present invention (example 1);

FIG. 2 is a scanning electron micrograph of an ionomer synthesized according to one embodiment of the present invention (example 1).

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The microspherical ionomer having a crosslinked structure provided by the present invention comprises a structural unit A represented by formula (1), a structural unit B provided by a mixed olefin, and a crosslinked structure provided by a crosslinking agent,

wherein M is₁And M₂Each independently H or a metal cation (in the ionomer, M is not present in all structural units A)₁And M₂All H, i.e. at least a portion of the structural units a of the ionomer have metal cations introduced therein), the mixed olefins being provided by carbon four and/or carbon five.

Wherein the metal cation may be various common metal ions, for example, Li⁺、Na⁺、K⁺、Ca²⁺、Mg²⁺、Ba²⁺Or Zn²⁺。

The term "C.sub.four" refers to the generic term for hydrocarbons having four carbon atoms (mainly including butenes), and generally, C.sub.four includes a certain amount of alkanes (e.g., n-butane) and other impurities which may be present, in addition to various butenes of different structure (e.g., trans-2-butene, cis-2-butene, n-butene, isobutene), but the content of olefins is usually in the range of 60 to 75% by weight; the term "carbon five" refers to the generic term for hydrocarbons having five carbon atoms (mainly including pentene), and generally, carbon five includes, in addition to various pentenes of different structures (e.g., dienes (isoprene, cyclopentadiene, 1, 4-pentadiene, piperylene) and monoolefins (1-pentene, 2-pentene, cyclopentene, 2-methyl-1-butene, 2-methyl-2-butene)), certain amounts of alkanes (e.g., n-pentane, isopentane, cyclopentane, 2-methylbutane), alkynes (e.g., butyne-2, 3-penten-1-yne), and other impurities that may be present, but the content of alkenes is typically in the range of 55 to 65 wt%. In the present invention, the amount of the mixed olefins is based on the total content of the terminal olefins in carbon four and/or carbon five.

In a preferred embodiment of the present invention, the molar ratio between the structural unit A and the structural unit B is 100: 100-.

In a further preferred embodiment of the present invention, the molar ratio of structural units A to crosslinked structures is 100: 1 to 40, more preferably 100: 10 to 30.

In the present invention, according to a preferred embodiment, the molar amount of metal cations in the ionomer is 10-120% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 100%, 110%, 115%, 120% or any value therebetween) of the total molar amount of structural units a in the ionomer. The degree of crosslinking of the ionomer is preferably greater than or equal to 65% (e.g., 65%, 70%, 75%, 80%, 85%, 90%, or any value therebetween). The ionomer is microspherical and has an average particle size of 150-2000nm (e.g., 150nm, 250nm, 350nm, 450nm, 550nm, 650nm, 750nm, 850nm, 950nm, 1050nm, 1150nm, 1250nm, 1350nm, 1450nm, 1550nm, 1650nm, 1750m, 1850nm, 2000nm, or any value therebetween). In the present invention, the molar content of the metal cation is obtained by X-ray fluorescence spectroscopic analysis. The degree of crosslinking is indicative of the gel content, as measured by the solvent extraction method. The average particle size is characterized by a number average particle size and is determined by means of a scanning electron microscope.

In the present invention, the crosslinking agent may be any of various conventional vinyl-containing monomers having two or more functionalities and capable of radical polymerization. Preferably, the crossingThe coupling agent is divinyl benzene and/or an acrylate crosslinking agent containing at least two acrylate groups, and the acrylate groups have the structural formula: -O-C (O) -C (R') ═ CH₂R' is H or C₁-C₄Alkyl (e.g., methyl).

More preferably, the crosslinking agent is selected from divinylbenzene, propylene glycol-based di (meth) acrylates (such as 1, 3-propylene glycol dimethacrylate, 1, 2-propylene glycol dimethacrylate, 1, 3-propylene glycol diacrylate, 1, 2-propylene glycol diacrylate), ethylene glycol-based di (meth) acrylates (ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate), trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, ethylene glycol dimethacrylate, propylene glycol-based di (meth) acrylates, ethylene glycol-acrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol triacrylate, trimethylolpropane triacrylate, propylene glycol trimethacrylate, propylene glycol triacrylate, propylene glycol dimethacrylate, and mixtures thereof, At least one of diethylene glycol diacrylate phthalate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ethoxylated multifunctional acrylate.

The present invention provides a method of making an ionomer comprising:

(2) salification (or hydrolysis) of the product obtained in step (1) by reaction with a base in the presence of water.

In the step (1) of the present invention, the amount of each raw material used is not particularly limited, and it is preferable that the amount of the mixed olefin in terms of terminal olefin is 50 to 200mol, more preferably 75 to 100mol, relative to 100mol of maleic anhydride. As can be appreciated by those skilled in the art, maleic anhydride is a substance that provides the structural unit A represented by the formula (1). The mixed olefin is a substance that provides the structural unit B represented by the formula (2).

Preferably, the crosslinking agent is used in an amount of 1 to 40mol, more preferably 10 to 20mol, and further preferably 15 to 20mol, relative to 100mol of maleic anhydride.

Preferably, the organic solvent is used in an amount of 50 to 150L, more preferably 75 to 100L, relative to 100mol of maleic anhydride.

Preferably, the initiator is used in an amount of 0.05 to 20mol, more preferably 1 to 8mol, relative to 100mol of maleic anhydride.

In step (1) of the present invention, the organic solvent may be any solvent commonly used in solution polymerization, for example, the organic solvent includes organic acid alkyl ester, that is, organic acid alkyl ester, or a mixture of organic acid alkyl ester and alkane, or a mixture of organic acid alkyl ester and aromatic hydrocarbon. Wherein the organic acid alkyl esters include, but are not limited to: at least one of methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isopentyl acetate, benzyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, and ethyl phenylacetate. Such alkanes include, but are not limited to: n-hexane and/or n-heptane. The aromatic hydrocarbons include, but are not limited to: at least one of benzene, toluene and xylene.

In step (1) of the present invention, the initiator may be a reagent commonly used in the art for initiating polymerization of maleic anhydride and olefin, and may be a thermal decomposition type initiator. Preferably, the initiator is at least one selected from the group consisting of dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, lauroyl peroxide, t-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile, and azobisisoheptonitrile.

In step (1) of the present invention, the specific types of the mixed olefin and the crosslinking agent are as described above and will not be described herein again.

In step (1) of the present invention, the reaction conditions are not particularly limited, but preferably such that the degree of crosslinking of the ionomer is 65% or more. More preferably, in step (1), the reaction conditions include: an inert atmosphere at a temperature of 50 to 90 ℃ (more preferably 60 to 70 ℃), a pressure (gauge pressure or relative pressure) of 0.3 to 1MPa (more preferably 0.4 to 0.5MPa), and a time of 3 to 15 hours (more preferably 5 to 12 hours).

According to the process of the invention, in step (2), the base is used in such a way that the molar amount of metal cations in the ionomer is in a certain range, preferably in the above range, as a percentage of the total molar amount of structural units provided by the maleic anhydride in the ionomer. The amount of the base may be conventionally selected, and preferably, the base is used in an amount of 10 to 200mol (e.g., 10mol, 50mol, 100mol, 150mol, 190mol, 200mol or any value therebetween) relative to 100mol of maleic anhydride. The base is preferably used in the form of an aqueous solution, the concentration of which is preferably from 1 to 30% by weight.

In the step (2) of the present invention, the base may be a basic substance (a basic substance capable of providing a metal cation (as described above)) conventionally used in the art as long as it can substitute a part of the carboxyl hydrogen in the polymer obtained in the step (1) after hydrolysis with a metal. Preferably, the base is selected from a hydroxide of a metal and/or an acetate of a metal. The metal may be a monovalent metal or a divalent metal, such as a group IA, IIA and/or IIB metal (particularly lithium, sodium, potassium, calcium, barium, zinc and/or magnesium). More preferably, the base is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, magnesium hydroxide, lithium acetate, sodium acetate, potassium acetate, calcium acetate, barium acetate, and zinc acetate.

In step (2) of the present invention, the salination may be carried out under conventional conditions, for example, the salination conditions include: the temperature is 20-100 deg.C (preferably 30-100 deg.C), and the time is 0.5-8h (preferably 0.5-6 h).

In step (2) of the present invention, the product (suspension) obtained in step (1) may be further subjected to post-treatment (separation, washing and drying) and then reacted with a base. The washing may employ a conventional washing solvent, for example, at least one of n-hexane, isohexane, cyclohexane, n-heptane, n-octane, isooctane, methanol, ethanol, n-propanol, isopropanol, diethyl ether, isopropyl ether, and methyl tert-butyl ether. The result of this salination is an ionomer-containing dispersion which is subjected to a further separation treatment to give the ionomer product, for example in the following manner: centrifuging, washing with water, washing with an organic solvent (the washing solvent as described above, i.e., at least one of n-hexane, isohexane, cyclohexane, n-heptane, n-octane, isooctane, methanol, ethanol, n-propanol, isopropanol, diethyl ether, isopropyl ether, and methyl tert-butyl ether can be used), centrifuging, and drying (e.g., vacuum drying).

The inventors of the present invention have found in their studies that the ionomer of the present invention can be efficiently obtained by directly reacting the suspension obtained in the step (1) with a base for salinization without performing a step of removing an organic solvent. Thus, according to a preferred embodiment of the invention, in step (2) of the invention, the product obtained in step (1) can be reacted directly with a base (one-pot process), so that after salification a mixed ionomer-containing system is obtained which is subjected to a further separation treatment to obtain the ionomer product, for example in the following manner: standing for layering, recycling the organic phase, centrifuging the heavy phase, washing with water, centrifuging, and drying (such as vacuum drying) to obtain the ionomer. The optimized method adopts a one-pot process, and the product post-treatment only needs one-time liquid-liquid separation, solid-liquid separation, washing and drying, so that the time consumption of a single batch is effectively shortened, the process flow is simplified, unit equipment is reduced, and the energy consumption is effectively reduced; the process only needs one organic solvent as a reaction medium, the solvent can be recycled only through layering and drying operations, a special water distribution device is not needed, layering can be achieved in the reactor, the solvent can be recycled without distillation and purification, energy is saved, consumption is reduced, and pollution of the organic solvent to the environment can be effectively reduced.

The invention also provides an ionomer prepared by the method. The ionomer prepared by the invention has a cross-linked structure and is microspherical, and the metal cation content, the molar ratio among all structural units, the cross-linking degree, the average particle diameter and the like of the ionomer are as described above, and are not described again.

In addition, the invention also provides application of the ionomer as a nucleating agent in modification of PET. In actual use, the ionomers of the present invention can be melt blended with PET. The ionomer may be used in an amount of 0.5 to 5g with respect to 100 g of PET. The temperature of the melt blending may be 250-300 ℃. The melt blending time may be 5-8 min. And extruding and granulating the product after melt blending to obtain the modified PET product.

The present invention will be described in detail below by way of examples. In the following examples and comparative examples, the vacuum drying conditions were: the vacuum degree is-0.095 MPa at 100 ℃ and the time is 8 h.

Example 1

This example illustrates the crosslinked microsphere ionomer and the preparation method thereof.

(1) The composition of the mixed butylene gas is as follows: trans-2-butene, 40.83 wt%; cis-2-butene, 18.18 wt%; n-butane, 24.29 wt.%; n-butenes, 9.52 wt%; isobutylene, 2.78 wt%; others, 4.4 wt%. The metered mixed butylene (the molar ratio of the maleic anhydride to the effective component (terminal olefin) in the mixed olefin is 1: 1) is introduced into 1L of isoamyl acetate solution containing 1mol/L of maleic anhydride, 0.05mol/L of azodiisobutyronitrile and 0.2mol/L of divinylbenzene in the nitrogen atmosphere, the relative pressure of the system is 0.5MPa through nitrogen stamping, and the system is reacted for 6 hours at 70 ℃. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min to obtain the crosslinked butylene/maleic anhydride polymer microspheres, washing and purifying by normal hexane, and drying in vacuum.

Determining the content of carbon and oxygen in the polymer by X-ray fluorescence spectrum analysis; analyzing the clear liquid after centrifugal separation by gas chromatography, and determining the content of the residual maleic anhydride and the crosslinking agent; and the molar ratio among the structural unit A, the structural unit B and the crosslinking structural unit in the polymer can be calculated by combining the analysis results, and is specifically shown in Table 1 (the same below).

(2) 14.5g of sodium hydroxide was dissolved in 350mL of water, and 50g of crosslinked butene/maleic anhydride polymer microspheres were added to an aqueous sodium hydroxide solution (1.5 mol of a base per mol of maleic anhydride) and reacted at 90 ℃ for 3 hours. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min, adding 400mL of water into the solid, stirring and washing the solid, centrifuging for 30 minutes by the centrifuge under the condition of 5000rad/min, adding 500mL of methanol into the solid, stirring and washing the solid, centrifuging for 30 minutes by the centrifuge under the condition of 5000rad/min, and drying the solid in vacuum to obtain the crosslinked butene/sodium maleate ionomer microsphere (marked as C1).

Example 2

This example illustrates the ionomeric microspheres of the present invention and methods of making the same.

(1) A metered mixed butene (maleic anhydride and the effective component (terminal olefin) in the mixed olefin in a molar ratio of 1: 0.75, the composition being the same as in example 1) was introduced into 1L of an isoamyl acetate solution containing 1mol/L of maleic anhydride, 0.01mol/L of azobisisobutyronitrile and 0.2mol/L of divinylbenzene in a nitrogen atmosphere, and the mixture was reacted at 60 ℃ for 12 hours under a relative pressure of 0.4MPa with nitrogen pressure. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min to obtain the crosslinked butylene/maleic anhydride polymer microspheres, washing and purifying by methanol, and drying in vacuum.

(2) 15.7g of sodium acetate trihydrate was dissolved in 300mL of water, and 50g of crosslinked butene/maleic anhydride polymer microspheres were added to an aqueous sodium acetate solution (0.43 mol of a base per mol of maleic anhydride) and reacted at 100 ℃ for 4 hours. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min, adding 400mL of water into the solid, stirring and washing the solid, centrifuging for 30 minutes by the centrifuge under the condition of 5000rad/min, adding 500mL of methanol into the solid, stirring and washing the solid, centrifuging for 30 minutes by the centrifuge under the condition of 5000rad/min, and drying the solid in vacuum to obtain the crosslinked butene/sodium maleate ionomer microsphere (marked as C2).

Example 3

(1) The mixed carbon five gas comprises the following components: dienes (isoprene, cyclopentadiene, 1, 4-pentadiene, piperylene), 47.83 wt%; monoolefin (1-pentene, 2-pentene, cyclopentene, 2-methyl-1-butene, 2-methyl-2-butene), 13.18% by weight; alkanes (n-pentane, isopentane, cyclopentane, 2-methylbutane), 21.29 wt%; alkyne (butyne-2, 3-penten-1-yne), 0.92 wt%; others, 16.78 wt%. The metered mixed carbon five (the molar ratio of the maleic anhydride to the effective component (terminal olefin) in the mixed olefin is 1: 1) is introduced into 1L of isoamyl acetate solution containing 1mol/L of maleic anhydride, 0.05mol/L of azodiisobutyronitrile and 0.1mol/L of divinylbenzene in the nitrogen atmosphere, and the mixed carbon five reacts for 6 hours at 70 ℃ under the relative pressure of 0.5MPa by nitrogen stamping.

(2) And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min to obtain the crosslinked pentene/maleic anhydride polymer microspheres, washing and purifying by methanol, and drying in vacuum.

10.8g of sodium hydroxide was dissolved in 350mL of water, and 50g of crosslinked pentene/maleic anhydride polymer microspheres were added to an aqueous sodium hydroxide solution (1 mol of a base per mol of maleic anhydride) to react at 90 ℃ for 3 hours. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min, adding 400mL of water into the solid, stirring and washing the solid, centrifuging the solid for 30 minutes by the centrifuge under the condition of 5000rad/min, adding 500mL of methanol into the solid, stirring and washing the solid, centrifuging the solid for 30 minutes by the centrifuge under the condition of 5000rad/min, and drying the solid in vacuum to obtain the crosslinked pentene/sodium maleate ionomer microsphere (marked as C3).

(3) 350g (11 wt%) of an aqueous sodium hydroxide solution was added to the reaction system obtained in the step (1), and the mixture was reacted at 90 ℃ for 3 hours. And standing and layering the reacted system, centrifuging and separating the heavy phase for 20 minutes by a centrifuge at 5000rad/min, adding 4L of water into the solid, stirring and washing the solid, centrifuging and separating for 20 minutes by the centrifuge at 5000rad/min, and drying the solid in vacuum to obtain the crosslinked pentene/sodium maleate ionomer microsphere (marked as C3-1).

Example 4

Ionomeric microspheres were prepared according to the method of example 1, except that the concentration of divinylbenzene in the solution was 0.075mol/L, giving ionomeric microspheres C4.

Comparative example 1

The reaction was carried out as in example 1, except that no crosslinking agent was used, and the specific procedure was as follows:

(1) the metered mixed butene (the molar ratio of the maleic anhydride to the effective component (terminal olefin) in the mixed olefin is 1: 1, the composition is the same as that in example 1) is introduced into 1L of isoamyl acetate solution containing 1mol/L of maleic anhydride and 0.05mol/L of azobisisobutyronitrile under the nitrogen atmosphere, nitrogen is pressed to the relative pressure of 0.5MPa, and the system reacts for 6 hours at 70 ℃. And centrifuging the reacted system for 30 minutes by a centrifuge under the condition of 5000rad/min to obtain a butene/maleic anhydride polymer, washing and purifying normal hexane, and drying in vacuum.

(2) 13.0g of sodium hydroxide was dissolved in 350mL of water, and 50g of a butene/maleic anhydride polymer was added to an aqueous sodium hydroxide solution (1 mol of a base per mol of maleic anhydride) to conduct a reaction at 90 ℃ for 3 hours. The reacted system was dried to give a butene/sodium maleate ionomer (designated as C-D1).

Test example 1

(1) The infrared spectroscopic analysis of the polymer obtained in example 1 showed that the ionomer was successfully synthesized as shown in FIG. 1, and the infrared spectroscopic analysis of examples 2 to 4 showed similar results to that of example 1, and all of the ionomers were successfully obtained.

(2) The ionomer microspheres prepared in the above examples and comparative examples were subjected to X-ray fluorescence spectroscopy to determine the metal cation content in the ionomer, i.e., the percentage of the total molar amount of the structural units a in the ionomer.

(3) The ionomers prepared in the above examples and comparative examples were examined by scanning electron microscopy, wherein the scanning electron microscopy of the ionomer obtained in example 1 is shown in fig. 2, and it can be seen that the ionomer of the present invention is in the form of microspheres. The average particle size and the degree of crosslinking of the ionomer microspheres (particle size test method: 500 microspheres were selected from an electron micrograph, the diameters thereof were measured, and the average particle size of the microspheres was calculated by a mathematical average method; degree of crosslinking test method: 2-3 g of polymer microspheres (w1) were weighed, wrapped with medium-speed qualitative filter paper, put into a soxhlet extractor, extracted with tetrahydrofuran for 24 hours, dried and weighed w2, and the degree of crosslinking was calculated by w2/w 1) were measured as shown in table 1 below, and the like.

TABLE 1

(4) The ionomer microspheres prepared in the above examples and comparative examples were respectively and uniformly mixed with PET, the addition amount of the ionomer microspheres was 1 wt% of the mass of PET, and then melt-blended at 280 ℃ for 8 minutes, and extruded and pelletized to obtain modified polyethylene terephthalate. The modified PET was subjected to Differential Scanning Calorimetry (DSC) tests and the results are shown in table 2 using unmodified PET as a control.

TABLE 2

Item	Cold crystallization Peak/deg.C	Melting crystallization Peak/deg.C	Half peak width/deg.C	ΔH/J·g^-1
					PET	-	151.7	23.3	-11.3
C1 modified PET	116.0	204.7	5.6	-35.8
					C2 modified PET	117.4	204.8	5.8	-34.9
C3 modified PET	118.7	202.5	6.5	-34.6
					C3-1 modified PET	119.0	203.1	6.8	-35.4
C4 modified PET	121.3	195.2	8.9	-33.0
					C-D1 modified PET	125.4	192.3	11.5	-32.8

The results in table 2 show that the ionomer prepared by the method of the present invention has a significantly better nucleation effect on PET than the comparative example, and can significantly increase the crystallization temperature of PET and accelerate the crystallization rate. Further, as can be seen by comparing example 1 with example 4 and comparative example 1, controlling the amount of the crosslinking agent within the preferred range enables to obtain a better nucleation effect.

Test example 2

In the test example, PET was purchased from China petrochemical certified chemical fiber, and the intrinsic viscosity was 0.7 dl/g; the nitrogen-phosphorus type halogen-free flame retardant (HT202A) is purchased from Jinan Taxing Fine chemical Co., Ltd; lubricant (PET100) was purchased from bluegrass inc; glass fibers (or fiberglass or GF) were purchased from zhejiang ganglite group ltd; the processing aid antioxidant was purchased from Ciba specialty Chemicals. The method comprises the following specific steps:

weighing 100 parts by weight of PET, 1.5 parts by weight of ionomer microspheres, 0.2 part by weight of processing aid (antioxidant 1010 and antioxidant 168 with the weight ratio of 1: 1), 8 parts by weight of flame retardant and 0.04 part by weight of lubricant, putting into a high-speed stirrer, uniformly stirring, and extruding at the temperature of 230-segment temperature, 245-segment temperature, 255-segment temperature, 260-segment temperature, by using WP ZSK25 double screws; adding glass fiber into a double-screw feeding port; adding the nitrogen-phosphorus type halogen-free flame retardant (HT202A) through lateral feeding, extruding, cooling, granulating, drying (100 ℃, 8h), and injecting into a standard sample wafer (the mold temperature is 60 ℃) by a Haitian 125 injection machine at the temperature of 230-:

a standard sample strip with the size of 250 mm (length) multiplied by 25 mm (width) multiplied by 10 mm (thickness) is obtained by injection of a 300 g injection machine (manufactured by Ningbo Haitian company) and the tensile strength and the elongation at break of the standard sample strip are measured by a GB/T1040-1992 plastic tensile property test method;

a standard sample strip with the size of 80 mm (length) multiplied by 10 mm (width) multiplied by 4 mm (thickness) is obtained by injection of a 300 g injection machine (manufactured by Ningbo Haitian company), and the bending strength and the bending modulus of the standard sample strip are measured by a GB/T9341-2008 plastic bending performance test method;

injecting by a 300 g injection machine (manufactured by Ningbo Haitian company) to obtain a standard sample strip with the size of 80 mm (length) multiplied by 10 mm (width) multiplied by 4 mm (thickness) and the gap of 2mm, and measuring the impact strength of the simply supported beam gap of the standard sample strip by using a measuring method of GB/T1043-93 plastic cantilever beam impact strength;

deformation conditions are as follows: two injection-molded sample squares (60 mm. times.60 mm. times.2 mm) were taken, one of them was placed in an oven at 120 ℃ for 2 hours, and the other was placed at normal temperature, and the deformation of the sample was observed.

The results show that the ionomer of the invention can ensure that the obtained plastic product has the tensile strength in the range of 119-145MPa, the elongation at break of about 2 percent, the bending strength in the range of 140-180MPa, the bending modulus in the range of 6-10GPa and the impact strength of a simple beam notch in the range of 5-10kJ/m²Within this range, no significant deformation was observed after placing in an oven at 120 ℃ for 2 hours.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A microspheroidal ionomer having a crosslinked structure, which comprises a structural unit A represented by the formula (1), a structural unit B provided by a mixed olefin and a crosslinked structure provided by a crosslinking agent,

the compound of the formula (1),

wherein M is₁And M₂Each independently H or a metal cation, the metal being a monovalent metal and/or a divalent metal, the mixed olefin being derived from carbon four and/or carbonFifthly, providing;

the crosslinking degree of the ionomer is more than or equal to 65 percent;

the method for measuring the crosslinking degree of the ionomer comprises the following steps: weighing 2-3 g of ionomer microspheres, recording the weight as w1, wrapping the microspheres by using medium-speed qualitative filter paper, putting the microspheres into a Soxhlet extractor, extracting the microspheres for 24 hours by using tetrahydrofuran, drying and weighing w2 on the ionomer, and calculating the crosslinking degree according to w2/w 1.

2. The ionomer of claim 1, wherein the molar ratio between structural unit a, structural unit B, and crosslinked structure is 100: 100-120: 1-40.

3. The ionomer of claim 2, wherein the molar ratio between structural unit a, structural unit B, and the crosslinked structure is 100: 100-105: 10-30.

4. The ionomer of claim 1, wherein the molar amount of metal cations in the ionomer is 10-120% of the total molar amount of structural units a in the ionomer; the average particle size of the ionomer is 150-2000 nm.

5. The ionomer of claim 1, wherein the crosslinker is divinylbenzene and/or an acrylate crosslinker comprising at least two acrylate groups of the formula: -O-C (O) -C (R') = CH₂R' is H or C₁-C₄Alkyl group of (1).

6. The ionomer of claim 1, wherein the crosslinker is selected from at least one of divinylbenzene, propylene glycol diacrylate, propylene glycol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, diethylene glycol diacrylate phthalate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ethoxylated multifunctional acrylates.

7. The ionomer of claim 1, wherein the crosslinker is polyethylene glycol diacrylate and/or polyethylene glycol dimethacrylate.

8. A method of making a microspheroidal ionomer, comprising:

(2) salifying the product obtained in step (1) by reacting it with a base in the presence of water;

the alkali is selected from hydroxides of metals and/or acetates of metals, and the metals are monovalent metals and/or divalent metals;

in the step (1), the reaction condition ensures that the crosslinking degree of the ionomer is more than or equal to 65 percent;

the method for measuring the crosslinking degree of the ionomer comprises the following steps: weighing 2-3 g of ionomer, recording the weight as w1, wrapping the ionomer by using medium-speed qualitative filter paper, putting the wrapped ionomer into a Soxhlet extractor, extracting the ionomer by using tetrahydrofuran for 24 hours, drying the ionomer, weighing w2, and calculating the crosslinking degree according to w2/w 1.

9. The method according to claim 8, wherein the mixed olefin is used in an amount of 50 to 200mol in terms of terminal olefin with respect to 100mol of maleic anhydride; the dosage of the cross-linking agent is 1-40 mol; the dosage of the organic solvent is 50-150L; the dosage of the initiator is 0.05-20 mol; the amount of the alkali is 10-200 mol.

10. The process according to claim 9, wherein the mixed olefin is used in an amount of 75 to 100mol in terms of terminal olefin relative to 100mol of maleic anhydride.

11. The method according to claim 9 or 10, wherein the crosslinking agent is used in an amount of 10 to 20mol with respect to 100mol of maleic anhydride.

12. The method according to claim 9 or 10, wherein the organic solvent is used in an amount of 75 to 100L with respect to 100mol of maleic anhydride.

13. The method according to claim 9 or 10, wherein the initiator is used in an amount of 1 to 8mol with respect to 100mol of maleic anhydride.

14. The method of any of claims 8-10, wherein the organic solvent comprises an organic acid alkyl ester;

and/or the initiator is selected from at least one of dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile and azobisisoheptonitrile;

and/or the crosslinking agent is divinyl benzene and/or an acrylate crosslinking agent containing at least two acrylate groups, and the acrylate groups have the structural formula: -O-C (O) -C (R') = CH₂R' is H or C₁-C₄Alkyl group of (1).

15. The method according to claim 14, wherein the crosslinking agent is selected from at least one of divinylbenzene, propylene glycol diacrylate, propylene glycol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, diethylene glycol diacrylate phthalate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and ethoxylated multifunctional acrylates.

16. The method of claim 14, wherein the crosslinking agent is polyethylene glycol diacrylate and/or polyethylene glycol dimethacrylate.

17. The method of claim 14, wherein the base is selected from at least one of lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide, magnesium hydroxide, lithium acetate, sodium acetate, potassium acetate, calcium acetate, barium acetate, and zinc acetate.

18. The method of claim 8, wherein in step (1), the reaction conditions comprise: inert atmosphere at 50-90 deg.C and 0.3-1MPa for 3-15 hr.

19. The method of claim 8, wherein in step (2), the salinated conditions comprise: the temperature is 20-100 ℃ and the time is 0.5-8 h.

20. A microspheroidal ionomer produced by the process of any one of claims 8 to 19.

21. Use of the ionomer of any one of claims 1-7 and 20 as a nucleating agent for the modification of polyethylene terephthalate.