WO2010099645A1

WO2010099645A1 - Method for coupling polyolefin chains

Info

Publication number: WO2010099645A1
Application number: PCT/CN2009/070599
Authority: WO
Inventors: 郑安呐; 李书召; 危大福; 肖苗苗; 胡福增; 管涌; 王书忠; 蒋蔚
Original assignee: 上海富元塑胶科技有限公司; 维龙(上海)新材料科技有限公司
Priority date: 2009-03-02
Filing date: 2009-03-02
Publication date: 2010-09-10

Abstract

Method for coupling polyolefin chains includes solution grafting or melt grafting polyolefin (100 pts. wt.) with a polyfunctional-containing alkene monomer (0-15 pts. wt.) in the presence of a second alkene monomer (0-15 pts. wt.) and an initiator (0.02-10.0 pts. wt.) at a determined temperature to obtain grafted polyolefin with a side chain comprising functional groups; then, by means of a solution-grafting or a melt-blending reaction, adding a polyfunctional organic coupling agent (0.1-20 pts. wt.) and an antioxidant (0-10.0 pts. wt.) to said grafted polyolefin (100 pts. wt.) at a specific temperature to obtain coupled polyolefin. Compared to the art, the method produces high-strength long-branched polyolefin with a controllable degree of coupling, at low cost and high production rates.

Description

Method for coupling polyolefin molecular chain

Technical field

The invention belongs to the technical field of polymer polymerization, processing and functionalization, and relates to a coupling method of a polyolefin molecular chain. Background technique

Polyolefin represented by polypropylene and polyethylene is one of the most widely used thermoplastic polymer materials. However, since the softening point of the semi-crystalline polypropylene is very close to the melting point, the melt strength rapidly drops after exceeding the melting point, resulting in a disadvantage of low melt strength and difficulty in blow molding and foaming. Polyethylene, due to its low melting point, low mechanical strength, and poor environmental stress resistance, limits the application range of polyethylene. By coupling modification, the heat shrinkage of polypropylene can be reduced, the impact strength of polypropylene can be increased, and the range of application can be expanded. The coupling treatment of polyethylene is an ideal method to improve the insufficiency of polyethylene. The three-dimensional network formed by coupling can greatly improve the thermal deformation, wear, viscous deformation, chemical resistance and stress crack resistance of polyethylene. , the impact and tensile strength of polyethylene are improved, the shrinkage rate is reduced, the use temperature is low, and the like, and the coupled product also has a shape memory function.

There are three main types of polyolefin coupling methods: peroxide crosslinking, irradiation crosslinking, and silane crosslinking. The irradiation cross-linking method is limited by thickness, and has the disadvantages of high cost and limited radiation source. The peroxide cross-linking method has low branching rate, easy degradation or excessive cross-linking, and is difficult to stabilize, and the silane cross-linking method exists. Water is required as a cross-linking catalyst, which can only be cross-linked after the product is finished. In fact, it lacks other industrial production value except for the pipe. It can be seen that the above three commonly used methods cannot satisfy the long-branched and industrial application of polyolefin.

Taking Chinese patent CN 1380344 as an example, it introduces a force chemistry method for melt-grafting vinyl monomers of polyolefin plastics, mixing vinyl monomers, lubricants and polyolefins with ultrasonic generators and ultrasonic sensors. In the extruder, a continuous extrusion grafting reaction is carried out to obtain a polyolefin graft polymer or copolymer. However, the apparatus used on the one hand is complicated, and the polyolefin used must be polyethylene or a copolymer containing ethylene segments, thereby limiting the application in polypropylene and having a low grafting ratio. Japanese Patent JP6172459 describes a technique for graft-modifying polyolefins by using an olefinic monomer and a peroxide in the presence of a special class of comonomers, which can prevent degradation and cross-linking. The combination increases the graft ratio of the vinyl monomer and is used for extrusion molding. Although this patent inhibits the degradation and cross-linking of polyolefins, the graft ratio of the ethylenic monomers is still not sufficiently improved. Most of these domestic patents use radiation grafting methods with high cost and poor grafting rate. For example, Chinese patents CN1485354 and CN1482151 use radiation grafting to obtain functionalized polyolefin resins.

Coupling polyolefins used in insulated cables, foamed materials, and thermoplastic elastomers at home and abroad are mostly prepared by peroxide crosslinking, irradiation crosslinking, and silane crosslinking. For example, the insulating cable prepared by the oxide cross-linking of Chinese patent CN1300085 reduces the size of the inner spherulites and improves the service life of the cable; Japanese patent JP9104052 prepares a drinking water bottle without odor by radiation crosslinking; Chinese patent CN1438262 introduces a kind Silane crosslinked polyolefin elastomer composition. Summary of the invention

The object of the present invention is to provide a coupling of a polyolefin molecular chain capable of producing high-strength long-branched polyolefin, controllable coupling degree, low cost and high productivity, in order to overcome the deficiencies of the prior art mentioned above. method.

The object of the present invention can be achieved by the following technical solutions: A method for coupling a polyolefin molecular chain, characterized in that the method is applied by a solution grafting reaction or a melt grafting reaction in an amount of 0.02 to 10.0 parts by weight of an initiator. Next, 0 to 15 parts by weight of the polyfunctional group-containing monomer is grafted with 100 parts by weight of the polyolefin at a certain temperature under the synergistic action of 0 to 15 parts by weight of the second olefin monomer to prepare a side chain. a functionalized grafted polyolefin; 100 parts by weight of a grafted polyolefin, 0.1 to 20 parts by weight of a polyfunctional organic coupling agent and 0 to 10.0 parts by weight at a certain temperature by solution reaction or melt blending reaction The grafting polyolefin is coupled with an antioxidant.

The polyolefin comprises a copolymer of general-purpose polypropylene, general-purpose polyethylene or ethylene propylene having a melt flow rate of 0.1 g/10 min to 50 g/10 min _; the polyfunctional group-containing monomer comprising acrylic acid, Maleic anhydride, methacrylic acid, fumaric acid, itaconic acid, undecylenic acid, glycidyl methacrylate, acrylamide, N-methylol acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate One or more of the second olefin monomers include styrene, divinylbenzene, a-methylstyrene, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate One or more of the initiators; the initiator includes dicumyl peroxide, benzoyl peroxide, dodecyl peroxide, di-tert-butyl peroxide, t-butyl hydroperoxide, tert-butyl Base benzoate, 1, 4-bis(tert-butylperoxyisopropyl)benzene, or one or more of azobisisobutyronitrile and azobishesin.

The solution grafting method comprises the steps of: adding 100 parts by weight of a polyolefin resin, 0 to 15 parts by weight of a polyfunctional group-containing monomer monomer, and 0 to 15 parts by weight of a second olefin monomer to an organic solvent. In the middle, gradually heat up, and stir to form a uniform solution of 5%~15%. After removing oxygen by drum nitrogen, gradually add 0.02~10.0 parts by weight of initiator to 3~5 times, and maintain the temperature reaction for 2~4 hours. After the reaction is over, The reaction solution is cooled, the solid is precipitated, filtered, and dried to obtain a grafted polyolefin.

The organic solvent includes xylene, toluene, trichlorobenzene, chloroform.

The melt grafting method comprises the steps of: 100 parts by weight of a polyolefin resin, 0 to 15 parts by weight of a polyfunctional group-containing monomer, 0 to 15 parts by weight of a second olefin monomer, and 0.02 to 10.0 The parts by weight of the initiator are mixed at high speed and then added to a Huck, single screw extruder, twin screw extruder, internal mixer, Banbury mixer or open mill, at 130 ° C ~ 250 ° C The melt grafting reaction is carried out for 1 min to 30 min, and the product is cooled and pelletized to obtain a graft polyolefin.

The structural formula of the polyfunctional organic coupling agent is as shown in formula I:

V Formula I R represents the main structure of the polyfunctional coupling agent, and includes an alkyl group, an aryl group, an aralkyl group, an oligomer or an organic structure containing various hetero atoms;

F, representing various functional functional groups, including a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an epoxy group, an isocyanate group, an amide group, a sulfonic acid group, an acid chloride group;

n , represents the number of functional groups, n l.

The antioxidant includes 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-a-dimethyl Amino-p-cresol, 2,4,6-tri-tert-butylphenol, dilauryl thiodipropionate, di(octadecyl) thiodipropionate, di(tetradecyl) thiodipropionate One or more of the antioxidant 1010, the antioxidant CA, the antioxidant B215, and the antioxidant B225.

The solution grafting method comprises the following steps: adding the prepared grafted polyolefin and an antioxidant to a polyolefin solvent, gradually heating up, and stirring to form a uniform solution of 5% to 15%, and removing nitrogen by drum After the oxygen is added, the polyfunctional organic coupling agent is added in one portion, and the temperature is maintained for 0.1 to 1 hour. After the reaction is completed, the reaction solution is cooled, and the solid is precipitated. After filtration and drying, a coupled polyolefin is obtained.

The polyolefin solvent includes xylene, toluene, trichlorobenzene, chloroform.

The melt grafting method comprises the following steps: mixing the grafted polyolefin, the antioxidant and the polyfunctional organic coupling agent in a high mixer, and then adding to the Huck, single screw extruder, double In a screw extruder, an internal mixer, a Banbury mixer or an open mill, the melting reaction is carried out at 130 ° C to 250 ° C for 1 min to 30 min, and the product is cooled and pelletized to obtain a coupled polymer. Olefins.

Compared with the prior art, the present invention reacts the polyfunctional group-containing monomer with the polyolefin by the synergistic action of the second olefin monomer by the solution grafting reaction or the melt grafting reaction under the action of the initiator. The grafting reaction is carried out at a certain temperature to prepare a graft polyolefin having a functional group in a side chain. The grafted polyolefin prepared is then coupled to a coupled, long-branched polyolefin by a solution reaction or a melt reaction using a polyfunctional organic coupling agent at a temperature. In this way, high-strength long-branched polyolefins can be produced with controlled coupling, low cost, and high productivity. Polyolefins of various coupling degrees can be prepared according to different use requirements, and the coupled polyolefin prepared by the method can be widely used for foaming materials, pipes, cables, thermoplastic elastomers, beverage bottles, and plates. detailed description

Determination of grafting rate of polyfunctional olefinic monomers in grafted polyolefins

The grafting ratio of the polyfunctional olefinic monomer of the grafted polyolefin obtained by infrared spectroscopy was measured, and the relative intensity of the characteristic peaks before and after the extraction was measured. According to Lambert Beer's law, the reaction efficiency was determined. The calculation formula is:

Reaction efficiency = 100% * C ₂ / dd )

Wherein the concentration of the polyfunctional grafting monomer in the ratio;

Concentration of polyfunctional grafting monomer after c ₂ extraction

1 - d The concentration of the polyolefin before extraction, which is the initial charge of the polyolefin.

Determination of melt flow rate (MFR) of coupled polyolefin

The MFR was measured using a SRSY-1 melt flow rate meter at 230 ° C under a load of 2.16 kg.

Determination of storage modulus of coupled polyolefin

The PP sample was placed in a vacuum tableting machine at a temperature of 200 ° C, pressed for 30 min, and a sheet having a thickness of about 1 mm was prepared, and then the storage mold was tested by a Rheostress 600 rheometer manufactured by Thermo Haake. The following examples are illustrative of the invention and are not intended to limit the scope of the invention: The long-branched polyolefin prepared by the polyolefin coupling method of the present invention is composed of a specific amount of polyolefin resin, a specific amount of A functional group of an olefinic monomer, a specific amount of a second olefin monomer, and a specific amount of an initiator obtain a polyolefin having a side chain functional group by solution or melt grafting reaction. It is then obtained by solution or melt chemical reaction using a specific amount of a polyfunctional organic coupling agent and a specific amount of an antioxidant.

The materials and amounts used for the coupled polyolefin prepared by the polyolefin coupling method of the present invention are as follows:

(1) 100 parts by weight of a polyolefin resin, including a copolymer of polypropylene, polyethylene or ethylene propylene, having a melt flow rate of between 0.1 g/10 min and 50 g/10 min, preferably melting The body flow rate is lg/10 min to 30 g/10 min. The melt flow rate is too large or too small, which is unfavorable for the reaction of the polyolefin resin with the polyfunctional olefin-containing monomer, thereby lowering the reaction efficiency and affecting the branching rate of the final coupled polyolefin. Therefore, a further preferred polyolefin melt flow rate is from 3 g/10 min to 20 g/10 min.

(2) 0.1 to 25 parts by weight of a polyfunctional olefinic monomer, including acrylic acid, maleic anhydride, methacrylic acid, fumaric acid, itaconic acid, undecylenic acid, methyl One or more of glycidyl acrylate, acrylamide, N-methylol acrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate. The amount of addition is preferably 2 to 18 parts, more preferably 3 to 12 parts. 1份, if the amount of the polyfunctional monomer is less than 0.1 part, the amount of the polyfunctional monomer is less than 0.1 part, It is difficult to achieve the purpose of coupling.

(3) 0 to 25 parts by weight of the second olefin monomer, including methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, styrene, divinylbenzene, a-A One or several kinds of styrene. The amount of addition is preferably 2 to 18 parts, more preferably 3 to 12 parts. The addition of the olefin monomer can, on the one hand, increase the reaction efficiency of the polyfunctional group-containing monomer and, on the other hand, inhibit the degradation of the polyolefin. However, if the amount of the olefin monomer is more than 25 parts, the second olefin monomer will produce more homopolymer, which affects the performance of the coupled polyolefin.

(4) 0.02 to 10.0 parts by weight of an initiator, including dicumyl peroxide, benzoyl peroxide, dodecyl peroxide, di-tert-butyl peroxide, t-butyl hydroperoxide, Peroxide initiator such as t-butyl peroxybenzoate, 1, 4-bis(tert-butylperoxyisopropyl)benzene, and azo One or more of diisobutyl phthalate, azo diisoheptane, and the like. If the amount of the initiator is less than 0.02 part by weight, the concentration of the radical generated is too low, which lowers the reaction efficiency of the polyfunctional ethylenic monomer and the polyolefin, and affects the use properties of the coupled polyolefin. However, if the amount of the initiator is more than 10.0 parts by weight, serious crosslinking and degradation of the polyolefin may be caused, and in addition, the residual initiator may deteriorate the properties of the coupled polyolefin.

(5) The grafting reaction of the polyolefin can be carried out by a solution reaction and a melt reaction: the solution reaction is carried out by adding various materials other than the initiator to an organic solvent such as xylene, toluene, trichlorobenzene or chloroform. Gradually raise the temperature to 100 to 145 degrees and stir to form a uniform solution of 5% to 15%. After the nitrogen gas is removed from the drum, the initiator is gradually added in 3 to 5 times, and the temperature is maintained for 2 to 4 hours. After completion of the reaction, the reaction solution was cooled, and a solid precipitated, which was filtered and dried to obtain a graft polyolefin.

In the solution reaction, if the reaction temperature is lower than ioo °c, the polyolefin may be incompletely dissolved, making the grafting reaction difficult. If the reaction temperature is too high, the solvent is vigorously boiled so that the grafting reaction cannot be stably carried out.

The melt reaction is carried out by mixing various materials at high speed and then adding them to a Huck, a single screw extruder, a twin screw extruder, an internal mixer, a Banbury mixer, and an open mill at 130 ° C to 250 °. The melting reaction is carried out in the range of C, and it is more preferable to carry out the melting reaction in the range of from 120 ° C to 200 ° C, and the reaction time is from 1 min to 30 min, more preferably from 3 min to 8 min. The product is cooled and pelletized to obtain a grafted polyolefin.

In the melt reaction, if the reaction temperature is lower than 100 °C, the polyolefin cannot be completely melted, and the graft reaction is difficult to proceed. If the reaction temperature is higher than 250 °C, not only will the graft ratio of the polyolefin be lowered, but also the polyolefin product will be degraded and its physical properties deteriorated. If the reaction time is less than 1 min, the grafting reaction does not proceed completely, affecting the graft ratio of the polyolefin, and the residual initiator may deteriorate the properties of the polyolefin product. If the reaction time is more than 30 minutes, it is possible to degrade the polyolefin.

(6) 100 parts by weight of a graft polyolefin resin which is produced by the above-described polyolefin grafting method.

(7) 0. 1~20 parts by weight of a polyfunctional organic coupling agent having the formula: , , _F Formula I

R, represents the main structure of the polyfunctional coupling agent, such as an alkyl group, an aryl group, an aralkyl group, an oligomer or an organic structure containing various hetero atoms. For the solution reaction, it is preferred to use an organic substance in which R is an alkyl group; for the melt blending reaction, it is preferred that R is an oligomer or an aralkyl organic substance, which can enhance the compatibility of the polyfunctional organic coupling agent with the grafted polyolefin. , the coupling reaction proceeds smoothly.

F, representing various functional functional groups, such as a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an epoxy group, an isocyanate group, an amide group, a sulfonic acid group, an acid chloride group, etc., preferably using F as a primary amino group or a carboxyl group. As the functional group, it is further preferred to use a functional group in which F is a primary amino group, which accelerates the reaction rate of the polyfunctional organic group with the grafted polyolefin.

n , represents the number of functional groups, nl, preferably n = 2, at this time can effectively control the degree of coupling of the polyolefin, if n is too small, may not produce a coupling reaction, if n is too large, the coupling reaction will be lost Control, deteriorate the properties of the coupled polyolefin.

(8) 0 to 10 parts by weight of the antioxidant content, including 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2, 6-di-tert-butyl-α-dimethylamino-p-cresol, 2,4,6-tri-tert-butylphenol, dilauryl thiodipropionate, di(octadecyl) thiodipropionate, One or more of di(tetradecyl thiodipropionate), antioxidant 1010, antioxidant CA, antioxidant B215, and antioxidant B225. The addition of the antioxidant can adjust the reaction state and melt flowability of the coupled polyolefin, but if it is added in an amount of more than 10 parts, the use properties of the coupled polyolefin are deteriorated.

(9) The coupling of the grafted polyolefin can be generally carried out by the following two methods, thereby obtaining the coupled polyolefin of the present invention.

1) Solution reaction method: According to the above-mentioned ingredients, the grafted polyolefin prepared according to the above method is added to an organic solvent such as xylene, toluene, trichlorobenzene, chloroform, etc., and gradually heated, and stirred to form 5%~ 15% homogeneous solution. After the nitrogen is removed from the drum, the polyfunctional organic substance is added to the solution at a time, and the temperature is maintained for 0.5 to 1 hour. After completion of the reaction, the reaction solution was cooled, and a solid precipitated, which was filtered and dried to obtain a coupled polyolefin.

2) Melt reaction method: According to the ingredients described above, the graft polymerization prepared according to the above method The olefin, antioxidant and polyfunctional organic matter are mixed at high speed and then gradually added to the Huck, single screw extruder, twin screw extruder, internal mixer, Banbury mixer, open mill, at 160 The reaction is melted at a temperature of from ° C to 190 ° C for a period of from 1 min to 30 min. After granulation or pulverization, granulation is carried out to obtain a coupled polyolefin.

Examples and comparisons:

Examples and Comparative Examples 1 to 2 are preparations of long-branched polypropylene in solution:

Example 1: Polypropylene EPS30R (Qilu Petrochemical Co., Ltd.) 100 g, 1010 antioxidant 0.1 g, was added to a 2000 ml flask, and then 1300 g of xylene was added thereto, and the temperature was gradually raised to 140 °C. After the solid was completely dissolved, 2 g of an acrylic graft monomer, 2 g of styrene was added, and then 0.36 g of benzoyl peroxide was added to the flask 5 times in 30 minutes to maintain the reaction at 140 °C. After completion of the reaction, the flask was cooled to room temperature, 100 g of acetone was added, and the solid was completely precipitated by stirring, and then dried in a vacuum oven to obtain a graft polyolefin. The grafting ratio results of acrylic acid and polypropylene are shown in Table 1.

50 g of the grafted polypropylene prepared by the above method, 0.05 g of 1010 antioxidant was added to a 2000 ml flask, and then 1000 g of xylene was added thereto, and the temperature was gradually raised to 140 °C. After all the solids were dissolved, 1.4 g of 1,4 butanediol diglycidyl ether was added as a polyfunctional coupling agent to the flask in 5 minutes over 30 minutes, and the reaction was maintained at 140 °C. After completion of the reaction, the flask was cooled to room temperature, 100 g of acetone was added, and the solid was completely precipitated by stirring, and then dried in a vacuum oven to obtain a long-branched polyolefin. The properties of the long-branched polyolefin are listed in Table 1.

Comparative Example 1: 50 g of the grafted polypropylene prepared in Example 1 was taken. The grafting method of the grafted polypropylene was the same as in Example 1, except that 1.2 g of ethylene glycol diglycidyl ether was added as a coupling agent to the grafted polypropylene solution for coupling reaction. The properties of the obtained long-branched polypropylene are shown in Table 1.

Example 2: The polypropylene grafting method was the same as in Example 1, except that glycolic acid methacrylate was grafted with polypropylene as a grafting monomer. The coupling method was also the same as in Example 1, except that 0.65 g of hexamethylene diisocyanate (HDI) was added as a coupling agent to the grafted polypropylene solution for the coupling reaction. The results of the graft ratio of hydroxyethyl methacrylate to polypropylene and the properties of the obtained long-branched polyolefin are shown in Table 1.

Comparative Example 2: 50 g of the grafted polypropylene prepared in Example 2 was taken. The coupling method of the grafted polypropylene was the same as in Example 1, except that 0.67 g of toluene-2,4-diisocyanate (TDI) was added as a coupling agent to the grafted polypropylene solution for coupling reaction. The properties of the obtained long-branched polypropylene are listed in the table. 1 in.

Examples and Comparative Examples 3 to 4 are preparations of long-branched polypropylene by a melt method:

Example 3: Take polypropylene EPS30R (Qilu Petrochemical Co., Ltd.) 10 kg, GMA graft monomer 0.2 kg, styrene 0.2 kg, dicumyl peroxide 36 g, dissolve dicumyl peroxide in GMA And styrene monomer, and then all mixed in a high-speed mixer for 2 minutes, discharging. The mixture was added to a twin-screw extruder which had been preheated to 170 ° C, and the reaction was extruded at 50 rpm. The extruded product is pelletized to obtain a grafted polyolefin. The grafting ratio results of GMA and polyolefin are shown in Table 1.

5 kg of grafted polypropylene prepared by the above method, 20 g of an antioxidant, 40.8 g of hexamethylenediamine, and then all mixed in a high-speed mixer for 2 minutes were discharged. The mixture was added to a twin-screw extruder which had been preheated to 180 ° C and reacted and extruded at 80 rpm. The extruded product is pelletized to obtain a coupled polyolefin. The properties of the long-branched polyolefin are listed in Table 2.

Comparative Example 3: 5 kg of the grafted polypropylene prepared in Example 3 was taken. The coupling method of the grafted polypropylene was the same as in Example 3 except that 3 1.0 g of butanediamine was added as a coupling agent to the grafted polypropylene for the coupling reaction. The properties of the obtained long-branched polypropylene are shown in Table 2.

Example 4: Its polypropylene grafting method was the same as in Example 3 except that maleic anhydride was grafted with polypropylene as a grafting monomer. The coupling method was also the same as in Example 3 except that 74.5 g of octanediol was added as a coupling agent to the grafted polypropylene for coupling reaction. The results of the graft ratio of maleic anhydride to polypropylene and the properties of the obtained long-branched polyolefin are shown in Table 2.

Comparative Example 4: 5 kg of the grafted polypropylene prepared in Example 4 was taken. The coupling method of the grafted polypropylene was the same as in Example 4 except that 32.7 g of ethylene glycol was added as a coupling agent to the grafted polypropylene for the coupling reaction. The properties of the obtained long-branched polypropylene are shown in Table 2.

Table 1

It can be seen from Table 1 that both acrylic acid and hydroxyethyl methacrylate can be grafted with polypropylene, and the graft ratio is relatively high, and the graft ratio of hydroxyethyl methacrylate to acrylic acid is higher. This may be because hydroxyethyl methacrylate is more compatible with polypropylene than acrylic acid.

The long-branched polypropylene coupled with 1,4 butanediol diglycidyl ether and HDI has a lower melt flow rate than EPS30R, and the storage modulus is higher than EPS30R, indicating that after the coupling of the two coupling agents The polypropylene is effectively branched. The performance of polypropylene coupled with ethylene glycol diglycidyl ether and TDI was deteriorated. This is because the latter two coupling agents have a relatively short molecular chain and are embedded in the molecular chain of the polypropylene during the coupling reaction, resulting in a failure of the coupling reaction. The longer coupling agent can carry out the coupling reaction between different polypropylene molecular chains to cause the polypropylene to be branched. Table 2

It can also be seen from Table 2 that GMA and maleic anhydride have good grafting effect with polypropylene, and the grafting efficiency of the two reaches 80%. Moreover, hexamethylenediamine and octanediol having a long-chain structure can produce a good coupling effect for the grafted polypropylene.

Claims

Rights request

A method for coupling a molecular chain of a polyolefin, characterized in that the method comprises a solution grafting reaction or a melt grafting reaction, and comprises 0 to 15 parts by weight under the action of 0.02 to 10.0 parts by weight of an initiator. The functional group of the ethylenic monomer is grafted with 100 parts by weight of the polyolefin at a certain temperature under the synergistic action of 0 to 15 parts by weight of the second olefin monomer to prepare a grafted polyolefin having a functional group in the side chain; a grafted polyolefin, by solution reaction or melt blending reaction, adding 0.1 to 20 parts by weight of a polyfunctional organic coupling agent and 0 to 10.0 parts by weight of an antioxidant at a certain temperature to graft the graft The polyolefin is coupled.

2 . The method for coupling a polyolefin molecular chain according to claim 1 , wherein the polyolefin comprises a copolymer of general-purpose polypropylene, general-purpose polyethylene or ethylene propylene, and the melt flow rate thereof is 0. 1g/10min~50 g/10min _; the polyfunctional group-containing monomer includes acrylic acid, maleic anhydride, methacrylic acid, fumaric acid, itaconic acid, undecylenic acid, methacrylic acid One or more of glycidyl ester, acrylamide, N-methylol acrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate; the second olefin monomer comprises styrene, divinylbenzene, a One or more of methyl styrene, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate; the initiator includes dicumyl peroxide, benzoyl peroxide Acyl, dodecyl peroxide, di-tert-butyl peroxide, t-butyl hydroperoxide, t-butyl peroxybenzoate, 1, 4-bis(tert-butylperoxyisopropyl)benzene, Or one of azobisisobutanide and azobishesin Or several.

The method for coupling a polyolefin molecular chain according to claim 1, wherein the solution grafting method comprises the following steps: 100 parts by weight of a polyolefin resin, 0 to 15 parts by weight The polyfunctional group-containing monomer and 0 to 15 parts by weight of the second olefin monomer are added to the organic solvent, gradually heated, and stirred to form a uniform solution of 5% to 15%, and after the nitrogen gas is removed by the nitrogen gas, the fraction is 3 5% to 50.0 parts by weight of the initiator was gradually added thereto, and the temperature was maintained for 2 to 4 hours. After the completion of the reaction, the reaction solution was cooled, and the solid was precipitated. After filtration and drying, a graft polyolefin was obtained.

The method for coupling a polyolefin molecular chain according to claim 3, wherein the organic solvent comprises xylene, toluene, trichlorobenzene, chloroform.

5. The method for coupling a polyolefin molecular chain according to claim 1, wherein: The melt grafting method comprises the steps of: 100 parts by weight of a polyolefin resin, 0 to 15 parts by weight of a polyfunctional group-containing monomer, 0 to 15 parts by weight of a second olefin monomer, and 0.02 to 10.0 The parts by weight of the initiator are mixed at high speed and then added to a Huck, single screw extruder, twin screw extruder, internal mixer, Banbury mixer or open mill at 130 ° C to 250 ° C. The melt grafting reaction is carried out for 1 min to 30 min, and the product is cooled and pelletized to obtain a graft polyolefin.

The method for coupling a polyolefin molecular chain according to claim 1, wherein the polyfunctional organic coupling agent has the structural formula:

Formula I

R, representing the main structure of the polyfunctional coupling agent, including an alkyl group, an aryl group, an aralkyl group, an oligomer or an organic structure containing various hetero atoms;

n , represents the number of functional groups, n l.

The method for coupling a polyolefin molecular chain according to claim 1, wherein the antioxidant comprises 2,6-di-tert-butyl-4-ethylphenol, 2,6- Di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-a-dimethylamino-p-cresol, 2,4,6-tri-tert-butylphenol, dilauryl thiodipropionate One or more of bis(octadecyl thiodipropionate), di(tetradecyl thiodipropionate), antioxidant 1010, antioxidant CA, antioxidant B215, and antioxidant B225 Kind.

The method for coupling a polyolefin molecular chain according to claim 1, wherein the solution grafting method comprises the following steps: adding the prepared graft polyolefin and an antioxidant to the polyolefin In the solvent, gradually increase the temperature, and stir to form a uniform solution of 5%~15%. After removing the oxygen by the nitrogen gas, the organic coupling agent containing the polyfunctional group is added in one time, and the temperature reaction is maintained for 0.1 to 1 hour. After the reaction is finished, The reaction solution was cooled, and a solid precipitated, which was filtered and dried to obtain a coupled polyolefin.

The method for coupling a polyolefin molecular chain according to claim 8, wherein the polyolefin solvent comprises xylene, toluene, trichlorobenzene, chloroform.

10. The method for coupling a polyolefin molecular chain according to claim 1, wherein: The melt grafting method comprises the following steps: mixing the grafted polyolefin, the antioxidant and the polyfunctional organic coupling agent in a high mixer, and then adding to the Huck, single screw extruder, double In a screw extruder, an internal mixer, a Banbury mixer or an open mill, the melting reaction is carried out at 130 ° C to 250 ° C for 1 min to 30 min, and the product is cooled and pelletized to obtain a coupled polymer. Olefins.