Modified ethylene propylene diene monomer and preparation method thereof
阅读说明：本技术 改性三元乙丙橡胶及其制备方法 (Modified ethylene propylene diene monomer and preparation method thereof ) 是由 邵明波 罗俊杰 张利霞 赵姜维 唐正伟 于 2020-06-22 设计创作，主要内容包括：本发明涉及橡胶领域,公开了一种改性三元乙丙橡胶及其制备方法。该改性三元乙丙橡胶含有乙烯提供的第一结构单元、丙烯提供的第二结构单元和非共轭二烯单体提供的第三结构单元,至少部分第三结构单元含有式(1)所示结构的丙烯腈接枝基团,所述改性三元乙丙橡胶的重量为基准,所述改性三元乙丙橡胶的接枝率为1.1-4.9重量％。所述改性三元乙丙橡胶具有高的不饱和度、接枝率以及硫化速度,且改性后的乙丙橡胶对乙丙橡胶与其他极性橡胶并用时具有较好的增容效果。且其制备方法反应快速、步骤简单易实施的特点。(The invention relates to the field of rubber, and discloses modified ethylene propylene diene monomer rubber and a preparation method thereof. The modified ethylene propylene diene monomer rubber comprises a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by a non-conjugated diene monomer, wherein at least part of the third structural unit contains an acrylonitrile grafting group with a structure shown in a formula (1), the weight of the modified ethylene propylene diene monomer rubber is taken as a reference, and the grafting rate of the modified ethylene propylene diene monomer rubber is 1.1-4.9 wt%. The modified ethylene propylene diene monomer rubber has high unsaturation degree, grafting rate and vulcanization speed, and the modified ethylene propylene diene monomer rubber has a good compatibilization effect on ethylene propylene rubber and other polar rubbers when used together. And the preparation method has the characteristics of quick reaction, simple steps and easy implementation.)
1. The modified ethylene propylene diene monomer is characterized by comprising a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by a non-conjugated diene monomer, wherein at least part of the third structural unit contains an acrylonitrile grafting group with a structure shown in a formula (1); the weight of the modified ethylene propylene diene monomer is taken as a reference, and the grafting rate of the modified ethylene propylene diene monomer is 1.1-4.9 wt%;
2. the modified ethylene-propylene-diene rubber of claim 1, wherein the non-conjugated diene monomer is selected from one or more of 1, 4-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene.
3. The modified ethylene-propylene-diene rubber of claim 1 or 2, wherein the non-conjugated diene monomer is dicyclopentadiene;
preferably, at least part of the third structural units containing the grafting groups have a structure represented by formula (I),
4. modified ethylene propylene diene monomer according to any of claims 1 to 3, wherein the unsaturation degree of the modified ethylene propylene diene monomer is from 0.42 to 1.05mol/kg, preferably from 0.42 to 0.91 mol/kg.
5. The modified ethylene-propylene-diene rubber of any one of claims 1 to 4, wherein ethylene provides from 50 to 70 wt% of first structural units and the non-conjugated diene monomer provides from 4 to 8 wt% of third structural units, based on the weight of the modified ethylene-propylene-diene rubber;
preferably, the weight average molecular weight of the modified ethylene propylene diene monomer is 10-40 ten thousand, preferably 10-30 ten thousand.
6. A preparation method of modified ethylene propylene diene monomer is characterized by comprising the following steps: in the presence of a catalyst, contacting ethylene propylene diene monomer with acrylonitrile with a structure shown in a formula (2) in an organic solvent under the condition of olefin cross metathesis reaction, wherein the ethylene propylene diene monomer comprises a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by non-conjugated diene monomer,
7. the method according to claim 6, wherein the catalyst has a structure represented by formula (3),
wherein, in the formula (3), R1Is hydrogen, substituted or unsubstituted C2-C20 alkenyl, substituted orUnsubstituted C2-C20 alkynyl, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C2-C20 carboxylate, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C2-C20 alkenyloxy, substituted or unsubstituted C2-C20 alkynyloxy, substituted or unsubstituted C6-C20 aryloxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C20 alkylsulfonyl or substituted or unsubstituted C1-C20 alkylsulfinyl;
X1and X2Identical or different, are each independently anionic ligands,
L1and L2Identical or different, are each independently a neutral ligand, and optionally L1And L2Can be linked to each other to form bidentate neutral ligands.
8. The method of claim 7, wherein R1Is a substituted or unsubstituted aryl group of C6-C20, preferably phenyl;
X1and X2Each independently a halide ion, preferably chloride;
L1and L2Each independently a phosphine, amine, thioether, carbene, or a substituted or unsubstituted imidazolidine; preferably, L1And L2Each independently a phosphine, a carbene, or a substituted or unsubstituted imidazolidine.
9. The method of claim 7 or 8, wherein R1Is phenyl, L1Is a substituted or unsubstituted imidazolidine, L2Is phosphine, X1And X2Is the chlorine ion, and the chlorine ion is the chlorine ion,
preferably, the phosphine is a trialkylphosphine.
10. The method according to any one of claims 7 to 9, wherein the imidazolidine is an imidazolidine having a structure represented by the formula (4),
in the formula (4), R2And R3The same or different, each independently is a substituted or unsubstituted aryl group of C6-C20;
preferably, R2And R3Each independently isR4、R5、R6、R7And R8The same or different, each independently selected from hydrogen or substituted or unsubstituted C1-C5 alkyl;
more preferably, R2And R3Is composed of
11. The process according to any one of claims 6 to 10, wherein the non-conjugated diene monomer is selected from one or more of 1, 4-hexadiene, dicyclopentadiene and 5-ethylidene-2-norbornene, preferably dicyclopentadiene.
12. The method according to claims 6 to 11, wherein the acrylonitrile having the structure represented by formula (2) is used in an amount of 0.05 to 20 parts by weight and the catalyst is used in an amount of 0.05 to 10 parts by weight, relative to 100 parts by weight of the ethylene-propylene-diene monomer;
preferably, the ethylene-propylene-diene monomer contains 50-70 wt% of the first structural unit provided by ethylene and 4-8 wt% of the third structural unit provided by non-conjugated diene monomer;
preferably, the weight average molecular weight of the ethylene propylene diene monomer is 10-40 ten thousand, preferably 10-30 ten thousand.
13. The process of any of claims 6-12, wherein the olefin cross-metathesis conditions comprise: the olefin cross metathesis reaction is carried out in an inert atmosphere, and the reaction temperature is 0-150 ℃, preferably 20-100 ℃; the reaction time is 0.1 to 5 hours, preferably 0.1 to 3 hours.
14. The method according to any one of claims 6 to 13, wherein the catalyst is added to the reaction system in a single addition or in multiple additions;
preferably, the catalyst is added into the reaction system in 2-6 times, the time interval between two adjacent times of addition is 3-15 minutes, the difference of the catalyst addition amount of any two times accounts for less than 5 weight percent of the total catalyst addition amount,
more preferably, the organic solvent is selected from one or more of toluene, xylene, chlorobenzene, substituted or unsubstituted C6-C12 cycloalkanes, substituted or unsubstituted C5-C10 linear alkanes, tetrahydrofuran, acetone, and 1, 4-dioxane.
15. Modified ethylene propylene diene rubber prepared by the process according to any one of claims 6 to 14.
Technical Field
The invention relates to the field of rubber, in particular to modified ethylene propylene diene monomer, a preparation method of the modified ethylene propylene diene monomer and ethylene propylene diene monomer prepared by the method.
Background
The ethylene propylene diene monomer (ethylene propylene rubber) has excellent physical and chemical properties such as high elasticity, viscoelasticity, electrical insulation and the like, and is very prominent in application in aspects such as engineering plastic toughening, ozone aging resistance and the like. However, since ethylene propylene diene rubber is a nonpolar rubber, it is inferior in oil resistance, chemical resistance, self-adhesiveness and mutual adhesiveness, and it is expected that a rubber having a relatively excellent combination property can be obtained by combining with a diene rubber (e.g., natural rubber, butadiene rubber, nitrile rubber, chloroprene rubber, etc.). However, ethylene-propylene rubber has great difference with most diene rubbers in polarity and saturation, and is difficult to blend with polar polymers, so the application range of the ethylene-propylene rubber is limited to a certain extent. Therefore, it is important to modify the epdm rubber to enhance its compatibility with polar polymers.
The chemical modification of ethylene propylene diene monomer is to introduce other atoms or groups into the molecular chain through the chemical reaction of rubber to make the molecular chain have polarity or change the flexibility, so as to raise the compatibility of ethylene propylene rubber and diene rubber, that is, to introduce acrylonitrile, carboxyl and other polar groups into the main chain of ethylene propylene rubber, to modify ethylene propylene rubber as compatibilizer, so as to expand the application field of ethylene propylene rubber. The acrylonitrile modification is an important method in the chemical modification of the ethylene propylene rubber, and the acrylonitrile is introduced into the molecular chain of the ethylene propylene rubber through the chemical reaction of the ethylene propylene rubber and the acrylonitrile, so that the polarity of the molecular chain is increased, the compatibility of the ethylene propylene rubber and other high polymer materials is improved, and the application field of the ethylene propylene rubber is widened.
The acrylonitrile grafting reaction of the ethylene propylene diene monomer mainly takes radical reaction as main raw material, and the prepared modified ethylene propylene diene monomer has low grafting rate and low unsaturation degree, so that the vulcanization crosslinking efficiency of the ethylene propylene monomer is low, and the partial application of the ethylene propylene monomer is limited.
Disclosure of Invention
The invention aims to overcome the problem of low grafting rate and low unsaturation degree of acrylonitrile graft modified ethylene propylene diene monomer in the prior art, and provides modified ethylene propylene diene monomer, a preparation method of the modified ethylene propylene diene monomer and ethylene propylene diene monomer prepared by the method.
In order to achieve the above object, a first aspect of the present invention provides a modified ethylene-propylene-diene rubber comprising a first structural unit provided by ethylene, a second structural unit provided by propylene, and a third structural unit provided by a non-conjugated diene monomer, wherein at least a part of the third structural unit comprises an acrylonitrile graft group having a structure represented by formula (1); the weight of the modified ethylene propylene diene monomer is taken as a reference, and the grafting rate of the modified ethylene propylene diene monomer is 1.1-4.9 wt%;
the second aspect of the present invention provides a method for producing a modified ethylene propylene diene monomer, comprising: in the presence of a catalyst, contacting ethylene propylene diene monomer with acrylonitrile with a structure shown in a formula (2) in an organic solvent under the condition of olefin cross metathesis reaction, wherein the ethylene propylene diene monomer comprises a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by non-conjugated diene monomer,
the third aspect of the invention provides modified ethylene propylene diene monomer prepared by the preparation method.
Through the technical scheme, the modified ethylene propylene diene monomer, the preparation method of the modified ethylene propylene diene monomer and the ethylene propylene diene monomer prepared by the method have the following beneficial effects:
the molecular chain of the modified ethylene propylene diene monomer rubber provided by the invention is grafted with an acrylonitrile structural unit, and the modified ethylene propylene diene monomer rubber has high grafting rate and unsaturation degree, and specifically, the unsaturation degree of the modified ethylene propylene diene monomer rubber provided by the invention is 0.42-1.05mol/kg, and the grafting rate is 1.1-4.9 wt%.
Further, compared with the existing ethylene propylene diene monomer, the modified ethylene propylene diene monomer provided by the invention has higher vulcanization speed.
Furthermore, the preparation method of the modified ethylene propylene diene monomer provided by the invention has the characteristics of quick reaction, simplicity and easiness in implementation.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
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 invention provides a modified ethylene propylene diene monomer, which is characterized by comprising a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by a non-conjugated diene monomer, wherein at least part of the third structural unit contains an acrylonitrile grafting group with a structure shown in a formula (1); the weight of the modified ethylene propylene diene monomer is taken as a reference, and the grafting rate of the modified ethylene propylene diene monomer is 1.1-4.9 wt%;
in the invention, acrylonitrile is introduced into the side chain of the modified ethylene propylene diene monomer, so that the polarity of the ethylene propylene diene monomer is improved, the double bond content in the side chain of the modified ethylene propylene diene monomer is increased, and the vulcanization speed is improved.
In the present invention, it is noted that in the ethylene-propylene-diene monomer rubber, the first structural unit provided by ethylene has a structure represented by formula (III), the second structural unit provided by propylene has a structure represented by formula (IV),
in the present invention, the third structural unit may contain all of acrylonitrile, or a part of the third structural unit may contain acrylonitrile. In view of further improving the vulcanization speed of the modified ethylene propylene diene monomer, the grafting ratio of the modified ethylene propylene diene monomer is 1.1-4.9 wt% based on the weight of the modified ethylene propylene diene monomer.
In the invention, the grafting ratio is the mass content of the acrylonitrile with the structure shown in the formula (1) in the modified ethylene propylene diene monomer.
In the present invention, the non-conjugated diene monomer may be a non-conjugated diene monomer which is conventional in the art, and in particular, it is possible to perform an olefin cross metathesis reaction between an ethylene-propylene-diene monomer and acrylonitrile having a structure represented by formula (3), and for example, one or more of 1, 4-hexadiene, dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene may be used, and in order to obtain a higher graft ratio to increase the vulcanization rate of the modified ethylene-propylene-diene monomer, dicyclopentadiene is preferred.
According to the invention, when the non-conjugated diene monomer is dicyclopentadiene (DCPD), at least part of the third structural units containing the grafting groups have a structure represented by formula (I),
according to the invention, the unsaturation degree of the modified ethylene propylene diene monomer is 0.42-1.05mol/kg, preferably 0.42-0.91mol/kg, from the viewpoint of further improving the vulcanization speed of the modified ethylene propylene diene monomer.
The unsaturation degree of the modified ethylene propylene diene monomer rubber is measured by an iodometry method.
According to the invention, based on the weight of the modified ethylene propylene diene monomer, the content of the first structural unit provided by ethylene is 50-70 wt%, and the content of the third structural unit provided by the non-conjugated diene monomer is 4-8 wt%.
In the invention, the total content of a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by a non-conjugated diene monomer in the modified ethylene propylene diene monomer is 100 wt% based on the weight of the modified ethylene propylene diene monomer.
According to the invention, the weight average molecular weight of the modified ethylene propylene diene monomer is 10-40 ten thousand, preferably 10-30 ten thousand.
The weight average molecular weight of the modified ethylene propylene diene rubber of the present invention is measured by a Gel Permeation Chromatography (GPC) method.
The second aspect of the invention provides a preparation method of modified ethylene propylene diene monomer, which is characterized by comprising the following steps: in the presence of a catalyst, contacting ethylene propylene diene monomer with acrylonitrile with a structure shown in a formula (2) in an organic solvent under the condition of olefin cross metathesis reaction, wherein the ethylene propylene diene monomer comprises a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by non-conjugated diene monomer,
according to the invention, the catalyst has a structure represented by formula (3),
wherein, in the formula (3), R1Is hydrogen, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C2-C20 carboxylate, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C2-C20 alkenyloxy, substituted or unsubstituted C2-C20 alkynyloxy, substituted or unsubstituted C6-C20 aryloxy, substituted or unsubstituted C1-C20 alkylthio, substituted or unsubstituted C1-C20 alkylsulfonyl or substituted or unsubstituted C1-C20 alkylsulfinyl;
X1and X2Identical or different, are each independently anionic ligands,
L1and L2Identical or different, are each independently a neutral ligand, and optionally L1And L2Can be linked to each other to form bidentate neutral ligands.
According to the invention, in formula (3), R1Is a substituted or unsubstituted aryl group of C6-C20, preferably phenyl.
According to the invention, in formula (3), X1And X2Various anionic ligands may be common, for example each independently a halide, preferably chloride.
According to the invention, in the formula (3), L1And L2Various neutral ligands may be commonly used, and specific examples thereof may include, but are not limited to: a phosphine, amine, thioether, carbene, or a substituted or unsubstituted imidazolidine; preferably, L1And L2Each independently a phosphine, a carbene, or a substituted or unsubstituted imidazolidine. More preferably, L1Is a substituted or unsubstituted imidazolidine, L2Is a phosphine.
In one embodiment of the present invention, in formula (3), R1Is phenyl, L1Is a substituted or unsubstituted imidazolidine, L2Is phosphine, X1And X2Is chloride ion。
The phosphine may be a compound formed by partially or totally substituting hydrogen in each phosphine molecule with an organic group, preferably a trialkylphosphine, which may be the same or different, and each may be selected from an alkanyl group (e.g. C1-C10) or a substituted or unsubstituted cycloalkyl group (e.g. substituted or unsubstituted C6-C12), preferably each is selected from a substituted or unsubstituted cycloalkyl group, more preferably a cyclohexyl group.
Specifically, the phosphine is preferably a trialkyl phosphine, specific examples of which may include, but are not limited to: one or more of trimethylphosphine, triethylphosphine, tri-n-butylphosphine, tri-sec-butylphosphine, tripropylphosphine, tripentylphosphine, trihexylphosphine, trioctylphosphine and tricyclohexylphosphine.
According to the invention, the imidazolidine is an imidazolidine with a structure represented by the formula (4),
in the formula (4), R2And R3The same or different, each independently is a substituted or unsubstituted aryl group of C6-C20.
Preferably, R2And R3Each independently isR4、R5、R6、R7And R8The same or different, each independently selected from hydrogen or substituted or unsubstituted C1-C5 alkyl.
More preferably, R2And R3Is composed of
In the present invention, specific examples of the C1-C5 alkyl group may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl and n-pentyl.
In a preferred embodiment of the present invention, in formula (3),R1is phenyl, L1Is a substituted or unsubstituted imidazolidine, L2Is phosphine, X1And X2Is chloride ion.
In a more preferred embodiment of the present invention, in formula (3), R1Is phenyl, L1Is composed ofL2Is a trialkylphosphine, X1And X2Is chloride ion.
In the present invention, in order to provide the catalyst with a better catalytic effect, it is further preferable that the catalyst is a catalyst having a structure represented by formula (5),
in the above formula (5), PCy3Represents tricyclohexylphosphine, Ph represents phenyl.
The catalyst represented by the above formula (5) can be obtained commercially.
According to the present invention, the substituted or unsubstituted C2-C20 alkenyl group may be straight-chain or branched, and specific examples may include, but are not limited to: vinyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl.
According to the present invention, the substituted or unsubstituted alkynyl group of C2-C20 may be straight chain or branched, and specific examples may include, but are not limited to: ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl and decynyl.
According to the present invention, the substituted or unsubstituted C1-C20 alkyl group may be linear or branched, and specific examples may include, but are not limited to: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl, undecyl, dodecyl, octadecyl.
Specific examples of substituted or unsubstituted aryl groups of C6-C20 according to the present invention may include, but are not limited to: phenyl, methylphenyl, naphthyl.
According to the invention, the substituted or unsubstituted carboxylic ester group of C2-C20 means a group containing a carboxylic ester in the molecular chainSpecific examples may include, but are not limited to: methyl propionate, ethyl acetate and propyl formate.
Specific examples of substituted or unsubstituted alkoxy groups of C1-C20 according to the present invention may include, but are not limited to: methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, octadecyloxy.
Specific examples of substituted or unsubstituted alkenyloxy groups of C2-C20 according to the present invention may include, but are not limited to: 1-allyloxy, 2-alkenylbutoxy, 1-alkenylpentoxy.
Specific examples of substituted or unsubstituted alkynyloxy groups of C2-C20 according to the present invention may include, but are not limited to: 1-alkynylpropoxy, 2-alkynylbutoxy, 1-alkynylpentyloxy.
Specific examples of substituted or unsubstituted aryloxy groups from C6 to C20 according to the present invention may include, but are not limited to: phenoxy, naphthyloxy.
According to the present invention, the substituted or unsubstituted alkylthio group of C1 to C20 is a straight or branched C1 to C20 alkyl group bonded through one sulfur atom, and specific examples include, but are not limited to: methylthio (CH)3-S-), ethylthio, propylthio, butylthio, pentylthio, 1-methylpropylthio, 2-methylpropylthio and 1, 1-dimethylethylthio.
Specific examples of substituted or unsubstituted C1-C20 alkylsulfonyl groups according to the present invention may include, but are not limited to: methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, nonylsulfonyl.
Specific examples of substituted or unsubstituted C1-C20 alkylsulfinyl groups according to the present invention may include, but are not limited to: methylsulfinyl, ethylsulfinyl.
According to the invention, the non-conjugated diene monomer can be a non-conjugated diene commonly used in the art, so as to enable the ethylene-propylene-diene monomer and the acrylonitrile with the structure shown in the formula (2) to perform olefin cross metathesis reaction, for example, one or more of 1, 4-hexadiene, dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene can be used, and in order to obtain higher grafting ratio so as to improve the vulcanization speed and the compatibility of the modified ethylene-propylene-diene monomer, dicyclopentadiene (DCPD) is preferred.
According to the invention, the amount of the ethylene propylene diene monomer, the acrylonitrile having the structure shown in the formula (2) and the catalyst can be changed within a wide range as long as the purpose of obtaining a modified ethylene propylene diene monomer having a rapid reaction and high target saturation and grafting ratio can be achieved, and the amount of the acrylonitrile having the structure shown in the formula (2) is 0.5-20 parts by weight, preferably 1-12 parts by weight, relative to 100 parts by weight of the ethylene propylene diene monomer; the catalyst is used in an amount of 0.05 to 10 parts by weight, preferably 0.2 to 5 parts by weight.
According to the invention, the ethylene propylene diene monomer can be any ethylene propylene diene monomer capable of undergoing olefin cross metathesis reaction with acrylonitrile having a structure shown in formula (2) in the prior art, for example, the ethylene propylene diene monomer contains 50-70 wt% of first structural units provided by ethylene and 4-8 wt% of third structural units provided by non-conjugated diene monomers, based on the total weight of the ethylene propylene diene monomer.
In the invention, the total content of a first structural unit provided by ethylene, a second structural unit provided by propylene and a third structural unit provided by a non-conjugated diene monomer in the ethylene propylene diene monomer is 100 wt% by taking the total weight of the ethylene propylene diene monomer as a reference.
According to the invention, the weight average molecular weight of the ethylene propylene diene monomer is 10-40 ten thousand, preferably 10-30 ten thousand.
According to the present invention, the metathesis reaction can be carried out according to the conventional olefin cross-metathesis reaction in the prior art, for example, the cross-metathesis reaction of the olefin is preferably carried out under an inert atmosphere.
In the present invention, the inert atmosphere refers to a gas that does not participate in the reaction, such as: nitrogen and a gas of a group zero element of the periodic table, such as argon.
According to the present invention, the olefin cross-metathesis conditions include: the olefin cross metathesis reaction is carried out in an inert atmosphere, and the reaction temperature is 0-150 ℃, preferably 20-100 ℃; the reaction time is 0.1 to 5 hours, preferably 0.1 to 3 hours.
According to the present invention, the method of adding the catalyst is not particularly limited, and the catalyst may be added to the reaction system of ethylene propylene diene monomer and acrylonitrile having the structure represented by formula (2) in a single addition or in multiple additions.
In view of the fact that the addition of the catalyst at one time tends to cause a side reaction of acrylonitrile having a structure represented by formula (2) in the reaction system, it is preferable to add the catalyst in divided portions. More preferably, the catalyst is added into the reaction system in 2-6 times, the time interval between two adjacent times of addition is 3-15 minutes, and the difference between the catalyst addition amounts in any two times accounts for less than 5 wt% of the total catalyst addition amount, so that the catalyst is added in such a way to be beneficial to improving the grafting rate of the modified ethylene propylene diene rubber.
Further preferably, in order to make the catalyst have better catalytic effect, the catalyst is added into the reaction system in the form of solution (preferably, the catalyst is dissolved in the organic solvent) in 2-6 times, the time interval between two adjacent times of addition is 3-15 minutes, and the difference between the two catalyst additions accounts for less than 5 wt% of the total catalyst addition.
According to the invention, the organic solvent for preparing the modified ethylene propylene diene monomer rubber is various organic substances capable of being used as a reaction medium, and preferably, the organic solvent is selected from one or more of toluene, xylene, chlorobenzene, substituted or unsubstituted C6-C12 naphthenic hydrocarbon, substituted or unsubstituted C5-C10 straight-chain alkane, tetrahydrofuran, acetone and 1, 4-dioxane. Further preferably, the organic solvent is one or more of toluene, xylene, chlorobenzene, cyclohexane, n-hexane, tetrahydrofuran, acetone and 1, 4-dioxane; most preferred is toluene and/or xylene. These solvents may be used alone or in combination. The amount of the organic solvent may be selected conventionally in the art and will not be described herein.
According to the invention, the preparation method of the modified ethylene propylene diene monomer further comprises a purification step. The purification step may be a conventional purification step in the art, for example, a reaction solution obtained after the reaction is filtered with a nickel mesh, and acetone is added to the filtrate to form a precipitate, and then the resulting precipitate is filtered, washed and dried.
The third aspect of the invention provides the modified ethylene propylene diene monomer prepared by the method.
According to the modified ethylene propylene diene monomer disclosed by the invention, the grafting ratio of the modified ethylene propylene diene monomer is 1.1-4.9 wt% based on the weight of the modified ethylene propylene diene monomer.
According to the invention, the unsaturation degree of the modified ethylene propylene diene monomer rubber can be 0.42-1.05mol/kg, and is preferably 0.42-0.91 mol/kg.
According to the modified ethylene propylene diene monomer disclosed by the invention, the weight average molecular weight of the modified ethylene propylene diene monomer is preferably 10-40 ten thousand, and preferably 10-30 ten thousand.
The present invention will be described in detail below by way of examples.
The following preparations and examples relate to the following measurements of properties:
(1) the graft ratio was determined as follows:
ethylene propylene rubber (W) to be measured1And/g) and dimethylbenzene are added into a reaction kettle with nitrogen protection, acrylonitrile is added after ethylene propylene rubber is completely dissolved, and then catalyst solution is added in batches. After the reaction is finished, precipitating the reaction product by acetone, dissolving residual reactants in the reaction kettle by a proper amount of dimethylbenzene, precipitating by acetone, soxhlet extracting all precipitates by DMF, and vacuum drying at 60 ℃ to obtain the grafting product. Graft product weighing (W)2Per g), calculated as followsThe branch rate is as follows:
(2) the unsaturation degree of the modified ethylene propylene diene monomer is measured by an iodometry method, and the specific method is as follows: accurately weighing 2 g of modified ethylene propylene diene monomer sample, placing the sample in a 250mL ground conical flask, and adding 50mLCCl4Dissolving the sample, adding 20mL of iodine bromide (IBr) solution by a pipette, fully shaking, standing in the dark for 1h, then adding 10mL of 10 wt% potassium iodide solution, shaking up, titrating with 0.1N sodium thiosulfate standard solution until the solution is yellow, adding 5mL of starch indicator, and continuing to titrate until the blue disappears, namely the end point. And simultaneously performing a blank test. The unsaturation is calculated as follows:
in the formula, V0: the blank test consumes the volume, mL, of the sodium thiosulfate standard solution; v: the sample consumed the volume of sodium thiosulfate standard solution, mL; c: concentration of sodium thiosulfate standard solution, mol/L; m: sample mass, g. The unit of unsaturation in the formula is mol/kg.
(3) The weight average molecular weight of the modified ethylene propylene diene rubber was determined by means of Gel Permeation Chromatography (GPC) using a Waters 1515Isocratic HPLC gel chromatograph.
Ethylene-propylene-diene monomer ESPRENE 305, available from sumitomo, having an ethylene structural unit content of 65 wt%, a third structural unit content of 7 wt% provided by a non-conjugated diene monomer, which is dicyclopentadiene (DCPD), and a weight average molecular weight of 12 ten thousand;
ethylene propylene diene monomer 3280, available from Yanshan petrochemical company, having an ethylene structural unit content of 55 wt%, a third structural unit content provided by a non-conjugated diene monomer of weight average molecular weight of 30 ten thousand, the non-conjugated diene monomer being ENB;
acrylonitrile: commercially available from carbofuran technologies, inc;
catalyst I: having the structure shown below, commercially available from carbofuran technologies ltd;
wherein, PCy3Represents tricyclohexylphosphine, Ph represents phenyl;
catalyst II: having the structure shown below, commercially available from carbofuran technologies ltd;
wherein, PCy3Represents tricyclohexylphosphine, Ph represents phenyl;
catalyst III: having the structure shown below, commercially available from carbofuran technologies ltd;
wherein L isPCy3Represents tricyclohexylphosphine;
carbon black N550, available from Shanghai Kabot chemical Co., Ltd;
carbon black N330, available from Shanghai Kabot chemical Co., Ltd;
ASTM103# oil, available from ningbo co-evolution chemical ltd;
accelerator TMTD, available from shanghai essence-rubber science ltd;
sulfur, purchased from Shijiazhuang Ruiton chemical technology, Inc.;
nitrile rubber: 3945, available from Langshen;
ethylene propylene rubber: 2450, available from Langshen;
examples and comparative examples all other materials were commercially available.
Example 1
9 g of ethylene propylene diene monomer ESPRENE 305 and 1.08 g of acrylonitrile in N2Under protection, dissolving the mixture in 100mL of dimethylbenzene solution until the mixture is completely dissolved to form a reaction system; 0.045 g of catalyst I was also weighed and dissolved in 10mL of xylene solution to give catalyst solution C1.
Heating the obtained reaction system to 70 ℃, adding 2mL of catalyst solution C1 into the reaction system, after reacting for 5min, uniformly dividing the rest 8mL of catalyst solution C1 into 4 parts, adding into the reaction system in a manner of adding one part per 5min, and stopping the reaction after the last part of catalyst solution C1 is added into the reaction system for 5min, wherein the total reaction time is 30 min. After the reaction, the reaction solution was filtered with a nickel screen while it was hot, and acetone was added to the filtrate to remove impurities and precipitate. Separating out the precipitate, washing the precipitate with acetone until the filtrate is clear, and drying the precipitate in a vacuum oven at 60 ℃ for 14h to obtain the modified ethylene propylene diene monomer A1. The properties of the modified ethylene propylene diene rubber were analyzed and determined, and the results are shown in table 1.
Example 2
Modified ethylene-propylene-diene monomer was prepared in the same manner as in example 1, except that the reaction system was heated to 70 ℃ and then 10mL of the catalyst solution C1 was added to the reaction system at once, followed by reaction for 30 min. Obtaining the modified ethylene propylene diene monomer A2. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 3
Modified ethylene propylene diene monomer was prepared in the same manner as in example 2, except that the reaction system was heated to 70 ℃ and then 10mL of the catalyst solution C1 was added to the reaction system twice, the addition time was 5mL each time when the reaction system was heated to 70 ℃ i.e. when the reaction started and after the reaction proceeded for 15min, the reaction was stopped after 30min of reaction. Obtaining the modified ethylene propylene diene monomer A3. The properties of the modified ethylene propylene diene rubber were analyzed and determined, and the results are shown in table 1.
Comparative example 1
Ethylene propylene diene monomer, i.e., unmodified ethylene propylene diene monomer, was used as a reference ethylene propylene diene monomer D1, and the results of analytical determination of the reference ethylene propylene diene monomer D1 are shown in Table 1.
Example 4
A modified ethylene-propylene-diene monomer was prepared in the same manner as in example 1, except that the reaction time was 1 hour, that is, the reaction was stopped 35 minutes after the last portion of the catalyst solution was added to the reaction system. Obtaining the modified ethylene propylene diene monomer A4. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 5
Modified ethylene propylene diene monomer was prepared in the same manner as in example 1, except that the reaction system was heated to 40 ℃ to obtain modified ethylene propylene diene monomer A5. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 6
Modified ethylene-propylene-diene rubber was prepared in the same manner as in example 1, except that 0.81 g of acrylonitrile was added to obtain modified ethylene-propylene-diene rubber A6. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 7
Modified ethylene-propylene-diene monomer rubber was prepared in the same manner as in example 1, except that 0.08 g of catalyst I was weighed and dissolved in 10mL of xylene solution, and the solution was divided into 5 parts, and the manner of adding each part was the same as in example 1, to obtain modified ethylene-propylene-diene monomer rubber a 7. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 8
9 g of ethylene propylene diene monomer ESPRENE 305 and 0.1 g of acrylonitrile in N2Under protection, dissolving the mixture in 100mL of dimethylbenzene solution until the mixture is completely dissolved to form a reaction system; 0.45 g of catalyst I was also weighed and dissolved in 10mL of xylene solution to give catalyst solution C8.
Heating the reaction system to 20 ℃, adding 2mL of catalyst solution C8 into the reaction system, after reacting for 5min, uniformly dividing the rest 8mL of catalyst solution C8 into 4 parts, adding into the reaction system in a manner of adding one part per 5min, and stopping the reaction after the last part of catalyst solution C8 is added into the reaction system for 35min, wherein the total reaction time is 1 h. After the reaction, the reaction solution was filtered with a nickel screen while it was hot, and acetone was added to the filtrate to remove impurities and precipitate. Separating out the precipitate, washing the precipitate with acetone until the filtrate is clear, and drying the precipitate in a vacuum oven at 60 ℃ for 14h to obtain the modified ethylene propylene diene monomer A8. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 9
Mixing 9 g of ethylene propylene diene monomer 3280 and 0.54 g of acrylonitrile in N2Under protection, dissolving the mixture in 100mL of dimethylbenzene solution until the mixture is completely dissolved to form a reaction system; simultaneously, 0.018 g of catalyst I was weighed out and dissolved in 10mL of xylene solution to give catalyst solution C9.
Heating the reaction system to 100 ℃, adding 2mL of catalyst solution C9 into the reaction system, after reacting for 15min, uniformly dividing the rest 8mL of catalyst solution into 4 parts, adding one part of catalyst solution into the reaction system every 15min, and stopping the reaction after the last part of catalyst solution is added into the reaction system for 105min, wherein the total reaction time is 3 h. After the reaction, the reaction solution was filtered with a nickel screen while it was hot, and acetone was added to the filtrate to remove impurities and precipitate. Separating out the precipitate, washing the precipitate with acetone until the filtrate is clear, and drying the precipitate in a vacuum oven at 60 ℃ for 14h to obtain the modified ethylene propylene diene monomer A9. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Comparative example 2
Ethylene propylene diene monomer 3280, i.e., unmodified ethylene propylene diene monomer, was used as a reference ethylene propylene monomer D2, and the reference ethylene propylene diene monomer D2 was analyzed and measured, and the results are shown in Table 1.
Example 10
Modified ethylene propylene diene monomer rubber A10 was prepared in the same manner as in example 1, except that catalyst II was used in place of catalyst I. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
Example 11
Modified ethylene propylene diene monomer rubber A11 was prepared in the same manner as in example 1, except that catalyst I was replaced with catalyst III. The properties of the modified ethylene propylene diene monomer rubber were analyzed and determined, respectively, and the results are shown in table 1.
TABLE 1
Test example 1
The modified ethylene-propylene-diene rubbers A1-A11 prepared in examples 1 to 11 of the present invention were subjected to vulcanization property measurement in accordance with the following methods.
100 parts by weight of the modified ethylene propylene diene monomer A1 prepared in the invention example is placed on a double-roller rubber mixing mill, 5 parts by weight of active zinc oxide, 1 part by weight of stearic acid, 80 parts by weight of carbon black N550, 50 parts by weight of ASTM103# oil, 1 part by weight of accelerator TMTD and 1.5 parts by weight of sulfur are added in sequence at the temperature of 35 +/-5 ℃, and the mixture is uniformly mixed and mixed for 21 minutes to obtain a blend. And vulcanizing the blend for 15 minutes on a hydraulic flat vulcanizing machine with the temperature of 160 ℃ and the pressure of 15MPa to obtain the vulcanized ethylene propylene diene monomer rubber sheet.
The vulcanized ethylene propylene diene monomer rubber sheets were tested according to the method of GB/T16584-1996, and the vulcanization speed parameter, positive vulcanization time TC90, was recorded, and the test results are shown in Table 2.
The modified ethylene propylene diene monomer A2-A11 was subjected to vulcanization performance measurement in the manner described above, and the test results are shown in Table 2.
Comparative test example 1
An ethylene-propylene-diene monomer rubber sheet was produced in the same manner as in test example 1, except that a commercially available ethylene-propylene-diene monomer rubber D1(ESPRENE 305) was used in place of the modified ethylene-propylene-diene monomer rubber. The test results are shown in Table 2.
Comparative test example 2
An ethylene-propylene-diene monomer rubber sheet was produced in the same manner as in test example 1, except that a commercially available ethylene-propylene-diene monomer rubber D2(3280) was used in place of the modified ethylene-propylene-diene monomer rubber. The test results are shown in Table 2.
TABLE 2
Test example 2
The modified ethylene propylene diene rubbers A1-A11 prepared in examples 1 to 11 of the present invention were subjected to compatibilization measurement in accordance with the following methods.
Taking the use of the ethylene propylene rubber and the nitrile rubber as an example, a carbon black master batch method mixing process is adopted, the compatibilization effect of the ethylene propylene rubber grafted acrylonitrile on the ethylene propylene rubber/nitrile rubber mixed rubber is preliminarily inspected, and the basic formula (parts by mass) is as follows: nitrile rubber 70, ethylene propylene rubber 30, modified ethylene propylene rubber 5, an anti-aging agent MB 1, stearic acid 0.5, paraffin 1, carbon black N33040, polystyrene 10, dioctyl phthalate 12, dicumyl peroxide 3, trimethylolpropane trimethacrylate 1, trimethylolmethylamine 0.5 and triallyl isocyanurate 2.
Tensile strength was measured according to the method in GB 528-1998, and the results are shown in Table 3.
The vulcanized ethylene propylene diene monomer and nitrile rubber were tested in combination with film according to the method of GB/T16584-1996, and the vulcanization rate parameter, positive vulcanization time TC90, was recorded, and the test results are shown in Table 3.
Comparative test example 3
A blend of ethylene propylene rubber and nitrile rubber was prepared in the same manner as in test example 2, except that no modified ethylene propylene rubber was added during the test, and the test results are shown in Table 3.
TABLE 3
As can be seen from Table 1, acrylonitrile can be grafted to ethylene-propylene-diene rubber by cross metathesis using olefin, and the grafting ratio is relatively high and the reaction is rapid.
Comparing example 1 and example 9 with comparative example 1 and comparative example 2 (unmodified ethylene propylene diene monomer), the unsaturation degree of the modified ethylene propylene diene monomer obtained by the invention is 0.42-0.91mol/kg, and is obviously improved compared with the unmodified ethylene propylene diene monomer, because the side chain double bonds of the ethylene propylene diene monomer are increased after the acrylonitrile and the ethylene propylene diene monomer are subjected to olefin cross metathesis reaction.
Comparing the example 1 with the example 2, it can be seen that the grafting rate of the modified ethylene propylene diene rubber obtained by the method of dropping the catalyst in portions is higher, which is probably because the catalyst concentration in the system is higher after the catalyst is added at one time, and the acrylonitrile is easy to generate cross metathesis side reaction, so that the number of the acrylonitrile participating in the grafting reaction is reduced, and the grafting rate is reduced finally. Further, from example 2 to example 11, it can be seen that the degree of reaction can be effectively controlled by adjusting the reaction conditions, so that a modified ethylene-propylene-diene rubber having a desired graft ratio can be obtained.
As can be seen from the data in Table 2, the modified EPDM provided by the present invention has a significantly improved vulcanization rate compared with unmodified EPDM, mainly because acrylonitrile is introduced into the modified EPDM, and the unsaturation degree is improved to a certain extent.
As can be seen from the data in Table 3, the addition of a small amount of the modified graft copolymer to the ethylene-propylene rubber and nitrile rubber blend significantly increases the vulcanization rate and the tensile strength at break of the vulcanizate. This shows that the modified ethylene propylene diene rubber provided by the invention has better compatibilization effect.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.