阅读说明：本技术 一种邻苯二甲腈基固化物微球及其制备方法和应用 (Phthalonitrile-based cured material microsphere and preparation method and application thereof ) 是由 郭颖 周恒� 赵彤 丁江楠 栗昱博 于 2018-07-11 设计创作，主要内容包括：本发明提供了一种邻苯二甲腈基固化物微球及其制备方法和用途,所述方法是采用反应诱导相分离法制备邻苯二甲腈基固化物微球。邻苯二甲腈基化合物以珠滴状分散在热塑性大分子中,然后再用适当的有机溶剂洗去热塑性大分子,即可得到高耐热,近单分散,实心的邻苯二甲腈基固化物微球。这种制备方法操作简单,易于控制,收率接近100％,适合规模化工业生产。更重要的是,采用本发明制备的邻苯二甲腈基固化物微球增韧邻苯二甲腈基化合物(如式(I)所示邻苯二甲腈化合物或式(II)所示邻苯二甲腈低聚物)时,制备的固化物的冲击强度显著提高(如冲击强度可从7kJ/m<Sup>2</Sup>最高提高至23kJ/m<Sup>2</Sup>),显示了优异的增韧效果。(The invention provides phthalonitrile-based cured material microspheres and a preparation method and application thereof. The phthalonitrile-based compound is dispersed in the thermoplastic macromolecules in a bead shape, and then the thermoplastic macromolecules are washed away by using a proper organic solvent, so that the high-heat-resistance near-monodisperse solid phthalonitrile-based cured material microspheres can be obtained. The preparation method is simple to operate and easy to control, has the yield close to 100 percent, and is suitable for large-scale industrial production. More importantly, when the phthalonitrile-based cured material microspheres prepared by the method are used for toughening phthalonitrile-based compounds (phthalonitrile compounds shown in formula (I) or phthalonitrile oligomers shown in formula (II)), the impact strength of the prepared cured materials is remarkably improved (for example, the impact strength can be from 7 kJ/m) 2 The maximum is increased to 23kJ/m 2 ) And shows excellent toughening effect.)

1. A microsphere is a phthalonitrile-based cured microsphere and is characterized in that the chemical composition is a cured product of phthalonitrile-based compound.

2. The microsphere of claim 1, wherein the microsphere is a solid microsphere.

Preferably, the microspheres have a particle size in the range of 0.5-25 μm.

Preferably, the particle size distribution of the microspheres is between 5 and 25 μm.

Preferably, the glass transition temperature of the microspheres is above 400 ℃.

3. Microspheres according to claim 1 or 2, wherein the phthalonitrile based compound is one or more of a compound according to formula (I) or an oligomer according to formula (II):

in the formula (I), R is one of the following groups:

in the formula (II), R₁And R₂The same or different, each independently selected from-O-, -C_1～6Alkylene-; n is₁Is an integer of 1 to 5;

R₃and R₄Are the same or different and are each independently selected from-OH,

R₅is composed of

Preferably, R is

Preferably, R₁、R₂Are the same or different and are each independently selected from the group consisting of-O-and-C_1～4Alkylene- (more preferably-CH)₂-or-O-). More preferably, R₁、R₂Same, is selected from-CH₂-。

Preferably, R₃And R₄Are the same or different and are each independently selected from the group consisting of-OH and-OCH₂CH＝CH₂. More preferably, R₃And R₄And the same, is selected from-OH.

Preferably, R₅Is composed of

Preferably, the phthalonitrile-based compound may be a compound represented by formula (III):

preferably, the phthalonitrile-based compound may be an oligomer represented by formula (IV):

wherein n is₁Is an integer of 1 to 5.

4. A preparation method of phthalonitrile-based cured material microspheres comprises the following steps:

(1) dissolving a phthalonitrile-based compound, thermoplastic macromolecules and a catalyst in an organic solvent to obtain a mixed system;

(2) removing the organic solvent in the mixed system in the step (1), pouring and curing to obtain a cured substance;

(3) and (3) removing the thermoplastic macromolecules in the cured product obtained in the step (2) to prepare the phthalonitrile-based cured product microspheres.

Preferably, the phthalonitrile-based compound is as defined in claim 3.

Preferably, in the mixed system in the step (1), the mass ratio of the phthalonitrile-based compound to the thermoplastic macromolecule to the catalyst is 100: (20-60): (2-10) namely 100 parts by mass of the phthalonitrile-based compound, 20-60 parts by mass of the thermoplastic macromolecule and 2-10 parts by mass of the catalyst.

Preferably, in the mixed system in the step (1), the mass ratio of the phthalonitrile-based compound to the thermoplastic macromolecule to the catalyst is 100: (20-60): (2-6), alternatively 100: (20-40): (2-10).

Preferably, in the mixed system in the step (1), the mass ratio of the phthalonitrile-based compound to the thermoplastic macromolecule to the catalyst is 100: (20-40): (2-6).

Preferably, in the mixed system of the step (1), the mass of the organic solvent is 1 to 5 times, for example, 2 times the sum of the mass of the phthalonitrile-based compound, the thermoplastic macromolecule and the catalyst.

Preferably, the dissolution temperature of step (1) is 40-80 ℃.

Preferably, the thermoplastic macromolecule in step (1) is one or a mixture of several of polymethyl methacrylate, polyethylene glycol, polypropylene glycol, polylactic acid and polypropylene carbonate, and the molecular weight of the thermoplastic macromolecule is 5000-.

Preferably, the catalyst in step (1) is one or a mixture of stannous chloride, zinc chloride, p-toluenesulfonic acid, trifluorobenzene sulfonic acid, p-phenylenediamine, aniline, 4 ' -diaminodiphenylmethane, 4 ' -diaminodiphenyl sulfone, 2 ' -bis (4-hydroxyphenyl) propane and 1, 3-bis (3-aminophenoxy) benzene.

Preferably, the organic solvent in step (1) is one or a mixture of acetone, ethanol, n-propanol, n-butanol and ethyl acetate.

Preferably, the curing in step (2) is performed at 170-250 ℃ for 5-10 hours and then at 250-300 ℃ for 1-5 hours.

Preferably, the removal in step (3) is carried out by washing off the thermoplastic macromolecules contained in the cured product with an organic solvent; the organic solvent is one or a mixture of acetone, ethanol and ethyl acetate.

Preferably, the preparation method specifically comprises the following steps:

(1) dissolving 100 parts by mass of a phthalonitrile-based compound, 20-60 parts by mass of a thermoplastic macromolecule and 2-10 parts by mass of a catalyst in an organic solvent at 40-80 ℃, and uniformly mixing;

(2) removing the organic solvent at 25-80 deg.C, and pouring the obtained mixture into a mold; curing the mixture in the mold for 5-7 hours at the temperature of 170-250 ℃ and then curing for 1-5 hours at the temperature of 250-300 ℃ to obtain a cured product;

(3) dissolving thermoplastic macromolecules contained in the cured material by using an organic solvent to obtain the phthalonitrile-based cured material microspheres.

5. A phthalonitrile-based cured microsphere prepared by the method of claim 4.

6. Use of the phthalonitrile-based cured resin microspheres of any one of claims 1 to 3 or 5 for toughening a modified phthalonitrile-based cured resin.

7. A composition comprising a phthalonitrile-based compound and phthalonitrile-based cured resin microspheres as claimed in any one of claims 1 to 3 or 5.

8. The composition according to claim 7, wherein the phthalonitrile-based compound is as defined in claim 3.

Preferably, in the composition, the phthalonitrile-based cured material microspheres account for 0.5-10 wt%, preferably 1-5 wt% of the composition.

Preferably, the composition further comprises an organic solvent, wherein the organic solvent accounts for 500 wt% of the composition by weight, and preferably 300 wt% of the composition by weight.

Preferably, the organic solvent is selected from one or more of acetone, ethanol, ethyl acetate and N, N' -dimethylformamide.

9. A phthalonitrile-based resin cured product prepared by blending and curing the composition according to claim 7 or 8.

10. The method for producing a cured product of a phthalonitrile-based resin according to claim 9, which comprises the steps of:

and (2) blending and curing a phthalonitrile-based compound, an optional organic solvent and the phthalonitrile-based cured resin microspheres to prepare the phthalonitrile-based resin cured resin.

Preferably, the curing is performed at 170-250 ℃ for 5-10 hours, and then at 250-315 ℃ for 3-5 hours, such as 170 ℃/1h, 200 ℃/1h, 250 ℃/5h, 315 ℃/3 h.

Technical Field

The invention belongs to the technical field of thermosetting resin materials, and particularly relates to phthalonitrile-based cured material microspheres and a preparation method and application thereof.

Background

The phthalonitrile-based resin is a novel thermosetting resin system, belongs to one of cyano-based resins, and has a monomer molecular structural formula shown in a formula (a), wherein R is an organic group.

The triazine ring and phthalocyanine ring skeleton structure formed in the curing process of the phthalonitrile-based resin endows the phthalonitrile-based cured resin with excellent heat resistance, the long-term use temperature of the phthalonitrile-based cured resin is over 350 ℃, the glass transition temperature of the phthalonitrile-based cured resin is close to 450 ℃, and the 5 percent weight loss temperature of the phthalonitrile-based cured resin is over 500 ℃, so that the phthalonitrile-based cured resin has wide application fields. However, the high crosslinking density of the resin causes great brittleness of the resin, and cannot meet the requirement of high-performance composite materials on toughness, so that the further application of the resin is limited.

The commonly used thermosetting resin toughening modification methods mainly comprise the following steps: rubber modification, epoxy resin modification, thermoplastic macromolecule modification, rigid particle modification, and the like. But the temperature resistance grades of rubber, epoxy resin and thermoplastic macromolecules are all less than 300 ℃, so that the heat resistance of the toughened and modified phthalonitrile-based resin is obviously reduced. The rigid particles are adopted for toughening modification, the problem of uniform dispersion of the rigid particles needs to be solved, and the rigid particles and a resin matrix interface are obvious, so that the toughening effect cannot be achieved at times. Therefore, no ideal toughening modifier for the phthalonitrile-based resin exists at present.

Microsphere toughening is a new toughening method developed in recent years. Bismaleimide microspheres (CN200410040866.1) and epoxy microspheres (CN201510654028.1, cn201210297791.x) were also reported in succession. In 2018, Wu Xiao (Xiao Wu, Xin Yang, Ran Yu, Xiao-Juan Zhuao, Ying Zhuang, Weihuang. Highly crosshatched and unmom thermoset epoxy, prepaaration and toughening study, Polymer,2018,143,145 and 154) reported that epoxy microspheres modified epoxy resin, the resin toughness was increased nearly twice, and an excellent toughening effect was shown. However, because the epoxy microspheres and the bismaleimide microspheres have poor heat resistance, the heat resistance of the phthalonitrile resin can be obviously reduced during toughening, and the toughening effect cannot be achieved due to the decomposition of the microspheres.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide phthalonitrile-based cured material microspheres and a preparation method and application thereof. The phthalonitrile-based cured resin microspheres are used for toughening phthalonitrile-based cured resin and ensuring that the impact strength of a cured product of the phthalonitrile-based resin is from 7kJ/m²Increased to 23kJ/m²And shows excellent toughening effect.

The purpose of the invention is realized by the following technical scheme:

a microsphere is a phthalonitrile-based cured microsphere, and the chemical composition of the microsphere is a cured product of phthalonitrile-based compound.

According to an embodiment of the invention, the microspheres are solid microspheres.

According to the embodiment of the invention, the microspheres have uniform particle size, are full in sphere and have good monodispersity.

According to an embodiment of the invention, the microspheres have a particle size in the range of 0.5-25 μm.

According to an embodiment of the invention, the microspheres have a particle size distribution between 5 and 25 μm.

According to an embodiment of the invention, the glass transition temperature of the microspheres is above 400 ℃.

According to an embodiment of the present invention, the phthalonitrile-based compound is one or more of a compound of formula (I) or an oligomer of formula (II):

in the formula (I), R is one of the following groups:

in the formula (II), R₁And R₂The same or different, each independently selected from-O-, -C_1～6Alkylene-; n is₁Is an integer of 1 to 5;

R₃and R₄Are the same or different and are each independently selected from-OH,

-OCH＝CH_2、-OCH₂CH＝CH_2、-OCH₂C≡CH；

R₅is composed of

According to the embodiment of the present invention, if the phthalonitrile-based compound is a mixture, the component contents of each substance are not particularly limited, and may be in any ratio as long as the preparation of phthalonitrile-based cured microspheres of the present invention can be achieved.

Preferably, R is

Or

Preferably, R₁、R₂Are the same or different and are each independently selected from the group consisting of-O-and-C_1～4Alkylene- (more preferably-CH)₂-or-O-). More preferably, R₁、R₂Same, is selected from-CH₂-。

Preferably, R₃And R₄Are the same or different and are each independently selected from the group consisting of-OH and-OCH₂CH＝CH₂. More preferably, R₃And R₄Same is selected from-OH。

Preferably, R₅Is composed of

According to an embodiment of the present invention, the phthalonitrile-based compound may be a compound represented by formula (III):

according to an embodiment of the present invention, the phthalonitrile-based compound may be an oligomer represented by formula (IV):

wherein n is₁Is an integer of 1 to 5.

The invention also provides a preparation method of the phthalonitrile-based cured material microspheres, which comprises the following steps:

(1) dissolving a phthalonitrile-based compound, thermoplastic macromolecules and a catalyst in an organic solvent to obtain a mixed system;

(2) removing the organic solvent in the mixed system in the step (1), pouring and curing to obtain a cured substance;

(3) and (3) removing the thermoplastic macromolecules in the cured product obtained in the step (2) to prepare the phthalonitrile-based cured product microspheres.

According to an embodiment of the present invention, the phthalonitrile-based compound is as defined above.

According to an embodiment of the present invention, in the mixed system of step (1), the mass ratio of the phthalonitrile-based compound, the thermoplastic macromolecule, and the catalyst is 100: (20-60): (2-10) namely 100 parts by mass of the phthalonitrile-based compound, 20-60 parts by mass of the thermoplastic macromolecule and 2-10 parts by mass of the catalyst.

Preferably, in the mixed system in the step (1), the mass ratio of the phthalonitrile-based compound to the thermoplastic macromolecule to the catalyst is 100: (20-60): (2-6), alternatively 100: (20-40): (2-10).

Still preferably, in the mixed system of step (1), the mass ratio of the phthalonitrile-based compound, the thermoplastic macromolecule and the catalyst is 100: (20-40): (2-6).

According to an embodiment of the present invention, in the mixed system of step (1), the mass of the organic solvent is 1 to 5 times, for example, 2 times the sum of the mass of the phthalonitrile-based compound, the thermoplastic macromolecule and the catalyst.

According to an embodiment of the present invention, the dissolution temperature of step (1) is 40-80 ℃.

According to the embodiment of the present invention, the thermoplastic macromolecule in step (1) is one or more of polymethyl methacrylate, polyethylene glycol, polypropylene glycol, polylactic acid, and polypropylene carbonate, preferably, the molecular weight of the thermoplastic macromolecule is 5000-.

According to an embodiment of the present invention, the catalyst in step (1) is one or more of stannous chloride, zinc chloride, p-toluenesulfonic acid, trifluorobenzene sulfonic acid, p-phenylenediamine, aniline, 4 ' -diaminodiphenylmethane, 4 ' -diaminodiphenyl sulfone, 2 ' -bis (4-hydroxyphenyl) propane and 1, 3-bis (3-aminophenoxy) benzene.

According to an embodiment of the present invention, the organic solvent in step (1) is one or a mixture of acetone, ethanol, n-propanol, n-butanol and ethyl acetate.

According to the embodiment of the present invention, the removing method in the step (2) is a conventional manner known to those skilled in the art for removing the organic solvent in the mixed solution, and may be, for example, a manner of performing the removal of the organic solvent by rotary evaporation at a temperature of 80 to 100 ℃.

According to the embodiment of the present invention, the casting in step (2) is a conventional casting method known to those skilled in the art, and illustratively, the organic solvent-removed mixed system is cast in a mold, or is cast by other means.

According to the embodiment of the invention, the curing in the step (2) is performed for 5-10 hours at the temperature of 170-250 ℃ and then for 1-5 hours at the temperature of 250-300 ℃.

According to an embodiment of the present invention, the removing method described in the step (3) is a conventional manner known to those skilled in the art to remove the thermoplastic macromolecules in the cured product, and may be exemplified by dissolving the thermoplastic macromolecules with acetone at 25 to 40 ℃ and filtering.

According to the embodiment of the present invention, the removal in the step (3) is preferably to wash away the thermoplastic macromolecules contained in the cured product with an organic solvent; the organic solvent is one or a mixture of acetone, ethanol and ethyl acetate.

According to an embodiment of the present invention, the preparation method specifically comprises the steps of:

(1) dissolving 100 parts by mass of a phthalonitrile-based compound, 20-60 parts by mass of a thermoplastic macromolecule and 2-10 parts by mass of a catalyst in an organic solvent at 40-80 ℃, and uniformly mixing;

(2) removing the organic solvent at 25-80 deg.C, and pouring the obtained mixture into a mold; curing the mixture in the mold for 5-7 hours at the temperature of 170-250 ℃ and then curing for 1-5 hours at the temperature of 250-300 ℃ to obtain a cured product;

(3) dissolving thermoplastic macromolecules contained in the cured material by using an organic solvent to obtain the phthalonitrile-based cured material microspheres.

The invention also provides phthalonitrile-based cured material microspheres, which are prepared by the method.

The invention also provides application of the phthalonitrile-based cured resin microspheres in toughening modified phthalonitrile-based cured resin.

The invention also provides a composition which comprises the phthalonitrile-based compound and the phthalonitrile-based cured material microsphere.

According to an embodiment of the present invention, the phthalonitrile-based compound is as defined above.

According to the invention, in the composition, the phthalonitrile-based cured material microspheres account for 0.5-10 wt%, preferably 1-5 wt% of the composition.

According to the invention, the composition further comprises an organic solvent, wherein the organic solvent accounts for 500 wt% of the composition by weight, and preferably 300 wt% of the composition by weight.

According to the invention, the organic solvent is selected, for example, from one or a mixture of several of acetone, ethanol, ethyl acetate and N, N' -dimethylformamide.

The invention also provides a phthalonitrile-based resin cured product which is prepared by blending and curing the composition.

The invention also provides a preparation method of the phthalonitrile-based resin cured product, which comprises the following steps:

and (2) blending and curing a phthalonitrile-based compound, an optional organic solvent and the phthalonitrile-based cured resin microspheres to prepare the phthalonitrile-based resin cured resin.

The blending according to the present invention is carried out by conventional mixing means known to those skilled in the art, for example, by stirring after mixing.

According to the invention, the curing is performed in the temperature range of 170-250 ℃ for 5-10 hours, and then in the temperature range of 250-315 ℃ for 3-5 hours, such as 170 ℃/1 hour, 200 ℃/1 hour, 250 ℃/5 hour, 315 ℃/3 hour.

The invention has the beneficial effects that:

the invention provides phthalonitrile-based cured material microspheres and a preparation method and application thereof. The reaction induced phase separation method is that before the curing reaction begins, a solvent or thermoplastic macromolecules and thermosetting resin (phthalonitrile-based compound) are in a homogeneous phase state, the molecular weight of the thermosetting resin is gradually increased along with the progress of the curing reaction, the compatibility with the thermoplastic macromolecules is gradually deteriorated, the thermosetting resin is not compatible any more in thermodynamics, phase separation begins to occur, and different phase state structures are formed. When the mass ratio of the phthalonitrile-based compound to the thermoplastic macromolecule is 100: (20-60) in the range of the molecular weight distribution of the phthalonitrile-based compound in the form of droplets dispersed in the thermoplastic macromolecule, followed by washing with a suitable organic solventRemoving thermoplastic macromolecules to obtain the high-heat-resistance near-monodisperse solid phthalonitrile-based cured material microspheres. The preparation method is simple to operate and easy to control, has the yield close to 100 percent, and is suitable for large-scale industrial production. More importantly, when the phthalonitrile-based cured material microspheres prepared by the method are used for toughening phthalonitrile-based compounds (phthalonitrile compounds shown in formula (I) or phthalonitrile oligomers shown in formula (II)), the impact strength of the prepared cured materials is remarkably improved (for example, the impact strength can be from 7 kJ/m)²The maximum is increased to 23kJ/m²) And shows excellent toughening effect.

Drawings

FIG. 1 is a Scanning Electron Microscope (SEM) image of phthalonitrile-based cured microspheres prepared in example 1 of the present invention;

FIG. 2 is a laser particle size distribution diagram of phthalonitrile-based cured microspheres prepared in example 1 of the present invention;

FIG. 3 is a DSC of phthalonitrile-based cured microspheres prepared in example 1 of the present invention;

FIG. 4 is a Scanning Electron Microscope (SEM) image of the cross section of phthalonitrile-based resin cured material (a casting) toughened by phthalonitrile-based cured material microspheres prepared in example 1 of the present invention.

Detailed Description

The preparation method of the present invention will be described in further detail with reference to specific examples. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.