CN115725148A - Composite polypropylene material and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of polypropylene materials, and discloses a composite polypropylene material and a preparation method thereof. The preparation method of the composite polypropylene material comprises the following steps: carrying out ball milling and mixing on the modified homo-polypropylene and the calcium carbonate modified co-polypropylene uniformly at a temperature of between 100 ℃ below zero and 10 ℃ below zero to obtain a polypropylene mixture; uniformly mixing a polypropylene mixture and a beta-crystal form nucleating agent, and then melting and extruding; the modified homopolymerized polypropylene is a product obtained by modifying homopolymerized polypropylene by using a modified monomer, wherein the modified monomer is at least one of 1,6-hexanediol diacrylate and tripropylene glycol diacrylate; the calcium carbonate modified polypropylene copolymer is a product of calcium carbonate modified polypropylene copolymer. The composite polypropylene material is prepared by the preparation method. The preparation method provided by the invention can prepare the composite polypropylene material with high rigidity and toughness.

Description

Composite polypropylene material and preparation method thereof

technical field

The invention relates to the technical field of polypropylene materials, in particular to a composite polypropylene material and a preparation method thereof.

Background technique

At present, the production of high-rigidity and high-toughness polypropylene materials mainly adopts methods such as mixing modification, nucleation modification, filling modification, or a combination of these methods.

In the technical solutions of some existing patent applications, homopolypropylene is used as a raw material, but in the subsequent melt co-extrusion process, due to shearing, the molecular chain of polypropylene is broken, resulting in the rigidity and toughness of the material. performance has declined. In order to keep the average molecular weight of polyolefin from decreasing in subsequent processing, the present invention uses electron beam radiation technology to treat polypropylene. Through this processing method, the molecular weight of polypropylene can be increased, and to a certain extent, it can be avoided in subsequent melt co-extrusion. The average molecular weight decreases during the process. In addition, after electron beam treatment, the molecular weight distribution of polypropylene can be transformed from a unimodal distribution to a bimodal distribution. The bimodal distribution of the molecular weight is conducive to improving the toughness performance on the basis of maintaining the rigidity of the material.

In the technical solutions of some existing patent applications, melt co-extrusion (twin-screw) is used to blend and modify homopolypropylene, copolypropylene and fillers. In order to improve the connectivity between different components, generally carry out Grafting treatment to improve connectivity between different components. However, for non-polar fillers such as calcium carbonate or talcum powder, the graft cannot be well combined with these inorganic materials, resulting in the sliding between the surface of the inorganic material and the surface of polypropylene, which affects the mechanical properties. The present invention addresses this problem by performing mechanochemical ball milling on calcium carbonate and acrylic acid, so that acrylic acid and calcium carbonate can be well combined, and then blending with polypropylene to make the three materials at the microscopic level A good combination can be obtained, and the performance advantages of each component can be further exerted.

At present, in the preparation of high-rigidity and high-toughness polypropylene technology, both homopolymerized polypropylene and copolymerized polypropylene adopt melt co-extrusion. Due to the large macroscopic particle size of the two polyolefins, they may not be fully mixed evenly during the mixing process, resulting in the inability to effectively improve the rigidity-toughness balance of the material.

In view of this, the present invention is proposed.

Contents of the invention

The object of the present invention is to provide a composite polypropylene material and a preparation method thereof.

The present invention is achieved like this:

In a first aspect, the present invention provides a method for preparing a composite polypropylene material, comprising:

The modified homopolypropylene and the calcium carbonate modified copolymerized polypropylene are ball-milled and mixed at -100°C to -10°C to obtain a polypropylene mixture;

The polypropylene mixture and the β-crystal nucleating agent are evenly mixed and then melt-extruded;

The modified homopolypropylene is a product of homopolypropylene modified by a modified monomer, and the modified monomer is at least one of 1,6-hexanediol diacrylate and tripropylene glycol diacrylate;

Calcium carbonate-modified copolymerized polypropylene is the product of calcium carbonate-modified copolymerized polypropylene.

In an optional embodiment, the way of modifying the monomer to modify the homopolypropylene is:

After mixing the homopolypropylene and the modified monomer, it is firstly subjected to banburying treatment and then to irradiation treatment;

Preferably, the conditions for banburying treatment are: 170°C-200°C for 30min-80min;

Preferably, the conditions of the irradiation treatment are: treatment at an irradiation intensity of 0.5kGy-10kGy for 30min-80min.

In an optional embodiment, the amount ratio of homopolypropylene to modified monomer is 100g:1-100mmol;

Preferably, an antioxidant is also used when the monomer is modified to modify the homopolypropylene, and the mass ratio of the amount of the antioxidant to the homopolypropylene is 0.05-0.3:100.

In an optional embodiment, the mass ratio of the β crystal form nucleating agent to the polypropylene mixture is 0.01˜0.5:100.

In an optional embodiment, the mode of calcium carbonate modified polypropylene copolymer is:

The first part of acrylic acid and calcium carbonate are ball milled in a ball mill, so that the first part of acrylic acid is modified on calcium carbonate to obtain modified calcium carbonate;

The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene are uniformly mixed, and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene.

In an optional embodiment, the mass ratio of the first acrylic acid to calcium carbonate is 1-10:1-10, the mass ratio of the second acrylic acid to calcium carbonate is 1-100:1-100, and the copolymerized polypropylene and The mass ratio of calcium carbonate is 1-10:1-2.

In an optional embodiment, the ball milling conditions for the first part of acrylic acid and calcium carbonate in the ball mill are: ball milling speed range 10r/min～300r/min, pellet mass: material mass is 1～10:1～ 10. The ball milling time is 30-900 minutes.

In an optional embodiment, the mass ratio of the modified homopolypropylene to the calcium carbonate-modified copolymerized polypropylene is 1-10:1-10.

In an optional embodiment, the ball milling mixing conditions of the modified homopolypropylene and the calcium carbonate modified copolymer polypropylene are as follows: the ball milling speed range is 10r/min-500r/min, and the ball milling time is 1-100min.

In a second aspect, the present invention provides a composite polypropylene material, which is prepared by the preparation method according to any one of the foregoing embodiments.

The present invention has the following beneficial effects:

The preparation method of the composite polypropylene material provided by this application is to treat the mixture of modified homopolypropylene and calcium carbonate modified copolymer polypropylene at low temperature to make it close to the glass transition temperature, at which temperature the material becomes brittle , mixed ball milling can significantly improve the mixing properties of the two materials, and then melt extrusion can obtain a high-rigidity and high-toughness composite polypropylene material with good rigidity and toughness balance.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The composite polypropylene material provided by the embodiment of the present invention and its preparation method are described in detail below.

The preparation method of composite polypropylene material provided by the invention comprises:

The modified homopolypropylene and the calcium carbonate modified copolymerized polypropylene are ball-milled and mixed at -100°C to -10°C to obtain a polypropylene mixture;

The polypropylene mixture and the β-crystal nucleating agent are evenly mixed and then melt-extruded;

Modified homopolypropylene is the product of homopolypropylene modified by modified monomers. The modified monomers are 1,6-hexanediol diacrylate (HDDA) and tripropylene glycol diacrylate (TPGDA). at least one;

Calcium carbonate-modified copolymerized polypropylene is the product of calcium carbonate-modified copolymerized polypropylene.

In the preparation method provided by this application, the mixture of modified homopolypropylene and calcium carbonate modified copolymerized polypropylene is treated at low temperature to make it close to the glass transition temperature. At this temperature, the material becomes brittle and crushed by mixing ball milling , can significantly improve the mixing properties of the two materials, and then melt extrusion can obtain a high rigidity and high toughness composite polypropylene material with good rigidity and toughness balance.

Specifically, the preparation method of the composite polypropylene material provided by the embodiment of the present application includes:

S1. Preparation of modified homopolypropylene

The homopolypropylene and the modified monomer are mixed and then sent to the internal mixer for internal mixing treatment, then irradiated by an electron beam accelerator, and finally sent to the twin-screw extruder for high-temperature mixing and extrusion. A modified homopolypropylene is obtained.

Mixing and irradiation treatment can change the molecular weight distribution of homopolypropylene and increase the average molecular weight, thereby further improving the rigid performance indicators of polypropylene (tensile strength, flexural strength, flexural modulus, etc.), and through electron beam radiation Treatment can increase the surface activity of polypropylene, which is beneficial to the subsequent mixing performance with homopolypropylene materials.

Preferably, the conditions of banburying treatment are: 170°C-200°C (eg 170°C, 180°C, 190°C or 200°C) for 30min-80min (eg 30min, 50min, 60min or 80min);

Preferably, the irradiation treatment conditions are: 0.5kGy-10kGy (eg 0.5kGy, 1kGy, 2kGy, 4kGy, 6kGy, 8kGy or 10kGy) irradiation intensity for 30min-80min (eg 30min, 50min, 60min or 80min).

The specific banburying and irradiation conditions mentioned above can ensure the obtaining of modified homopolypropylene with concentrated average molecular weight and higher.

Modified monomer homopolypropylene can be modified to increase its rigidity index. Preferably, in order to ensure that the obtained composite polypropylene material has better rigidity, the ratio of homopolypropylene to modified monomer is 100g: 1-100mmol (eg 100g:1mmol, 100g:5mmol, 100g:10mmol, 100g:20mmol, 100g:40mmol, 100g:50mmol, 100g:60mmol, 100g:80mmol or 100g:100mmol), preferably 100g:40-60mmol.

Further, in order to improve the anti-oxidation performance of the composite polypropylene material, in this step, the antioxidant can also be mixed and banburyed together with the homopolypropylene and the modified monomer, then irradiated, and finally extruded to produce grain.

Preferably, in order to ensure that the prepared composite material has good oxidation resistance without affecting the rigidity and toughness of the composite material, the mass ratio of the amount of antioxidant added to the homopolypropylene is 0.05-0.3:100 ( For example 0.05:100, 0.1:100, 0.2:100 or 0.3:100).

Further, the antioxidant includes at least one of BASF Irganox 1010 and Irgafos 168, or the same antioxidant from other manufacturers as its component formulation.

S2, preparation of calcium carbonate modified polypropylene copolymer

The first part of acrylic acid and calcium carbonate are ball milled in a ball mill, so that the first part of acrylic acid is modified on calcium carbonate to obtain modified calcium carbonate;

The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene are uniformly mixed, and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene.

The first acrylic acid and calcium carbonate are mixed and ball-milled, and the calcium carbonate is mechanochemically modified to form a chemical bond between acrylic acid and calcium carbonate, which can further improve the subsequent combination of calcium carbonate and polypropylene in the modified material properties; the first and second parts of acrylic acid can improve the bonding strength between copolymerized polypropylene and homopolypropylene, so that the bonding of different components in the material can be improved.

Preferably, in order to obtain a composite polypropylene material with better performance, the mass ratio of the first acrylic acid to calcium carbonate is 1-10:1-10 (eg 1:10, 2:10, 5:10, 10:10, 10:1, 10:2 or 10:5), preferably 4～6:4～6 (such as 4:6, 1:1 or 6:4), the mass ratio of the second acrylic acid to calcium carbonate is 1～ 100:1～100 (such as 1:100, 10:100, 50:100, 100:100, 100:1, 100:10 or 10:50), preferably 1:2～7 (such as 1:2, 1 :3, 1:5 or 1:7), the mass ratio of copolymerized polypropylene to calcium carbonate is 1~10:1~2 (such as 10:1, 8:1, 6:1, 4:1, 2:1 , 1:1 or 1:2), preferably 5 to 10:1 (eg 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1).

Further, in order to ensure that acrylic acid can be fully combined with calcium carbonate chemical bonds, the ball milling conditions for the first part of acrylic acid and calcium carbonate in the ball mill are: ball milling speed range 10r/min～500r/min (such as 10r/min, 20r/min min. 50r/min. 100r/min. 200r/min. 300r/min. 2:10, 5:10, 10:10, 10:1, 10:2 or 10:5), the ball milling time is 30-900min (such as 30min, 50min, 80min, 100min, 200min, 400min, 600min or 900min), Preferably it is 60-120 min.

Preparation of S3, polypropylene mixture

After mixing the modified homopolypropylene and the calcium carbonate modified copolymerized polypropylene uniformly, the 10° C.) to obtain a polypropylene mixture evenly by ball milling.

Preferably, in order to obtain a composite polypropylene material with better rigidity and toughness, the mass ratio of modified homopolypropylene to calcium carbonate modified copolymer polypropylene is 1 to 10:1 to 10 (for example, 1:10, 2: 10, 5:10, 10:10, 10:1, 10:2, or 10:5).

Further, in order to ensure that the modified homopolypropylene and the calcium carbonate modified copolypropylene can be mixed more fully and evenly, the ball mill mixing conditions of the modified homopolypropylene and the calcium carbonate modified copolypropylene are as follows: the ball milling speed range is 10r/ min～500r/min (such as 10r/min, 20r/min, 50r/min, 100r/min, 200r/min, 300r/min, 400r/min or 500r/min), ball milling time is 1～100min (such as 1min, 10min, 20min, 40min, 60min, 80min or 100min).

S4, melt co-extrusion

After the obtained polypropylene mixture stops ball milling, the temperature is raised to normal temperature, then the polypropylene mixture is uniformly mixed with the β-crystal nucleating agent, and finally sent to a twin-screw extruder for melt co-extrusion to obtain a composite polypropylene material.

Preferably, in order to further ensure the preparation of a composite polypropylene material with better rigidity and toughness, the mass ratio of the amount of β crystal nucleating agent to the polypropylene mixture is 0.01-0.5:100 (for example, 0.01:100, 0.05:100 , 0.1:100, 0.2:100, 0.4:100 or 0.5:100), preferably 0.1 to 0.5:100.

The embodiment of the present application also provides a composite polypropylene material, which is prepared by the preparation method provided in the embodiment of the present application. The composite polypropylene material has high rigidity and toughness because it is prepared by the preparation method provided in the examples of the present application.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

Example 1

(1) After mixing homopolypropylene with an average molecular weight of 500,000, HDDA and antioxidant, it is first sent to the internal mixer for banburying treatment, then irradiated by an electron beam accelerator, and finally sent to twin-screw extrusion Extrude after kneading by machine to obtain modified homopolypropylene.

Antioxidant is 1010, and the mass ratio of its consumption and homopolypropylene is 0.05:100;

The consumption ratio of the consumption of HDDA and homopolypropylene is 1mmol: 100g;

The conditions of banburying treatment are: 170°C for 30 minutes;

The conditions of irradiation treatment are as follows: 30 minutes under the irradiation intensity of 0.5kGy.

(2) the first acrylic acid and calcium carbonate are ball milled in a ball mill, so that the first acrylic acid is modified to calcium carbonate to obtain modified calcium carbonate;

The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene with an average molecular weight of 350,000 are uniformly mixed, and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene.

The mass ratio of the first acrylic acid and calcium carbonate is 1:10, the mass ratio of the second acrylic acid and calcium carbonate is 1:100, and the mass ratio of copolymerized polypropylene and calcium carbonate is 10:1;

The ball milling conditions of the first acrylic acid and calcium carbonate in the ball mill are as follows: the ball milling speed range is 10r/min, the mass of the ball: the bulk volume ratio of the treated material is 1:10, and the ball milling time is 30min.

(3) After uniformly mixing the modified homopolypropylene and the calcium carbonate-modified copolymerized polypropylene, they are uniformly mixed by ball milling at -10° C. to obtain a polypropylene mixture.

The mass ratio of modified homopolymer polypropylene to calcium carbonate modified copolymer polypropylene is 1:10;

The ball milling mixing conditions of modified homopolypropylene and calcium carbonate modified copolypropylene are as follows: ball milling speed range 10r/min, ball milling time 1min.

(4) After ball milling, raise the temperature of the polypropylene mixture to normal temperature, then mix the polypropylene mixture with the β crystal nucleating agent evenly, and finally send it into a twin-screw extruder for melt co-extrusion to obtain a composite polypropylene material .

The mass ratio of the amount of β crystal form nucleating agent to the polypropylene mixture is 0.01:100.

Example 2

(1) After mixing homopolypropylene with an average molecular weight of 500,000, TPGDA and antioxidant, it is first sent to the internal mixer for banburying treatment, then irradiated by an electron beam accelerator, and finally sent to twin-screw extrusion Extrude after kneading by machine to obtain modified homopolypropylene.

Antioxidant is 1010, and the mass ratio of its consumption and homopolypropylene is 0.3:100;

The consumption ratio of the consumption of TPGDA and homopolypropylene is 100mmol:100g;

The conditions of banburying treatment are: 80 minutes at 200°C;

The conditions of irradiation treatment are as follows: 80 minutes under the irradiation intensity of 10kGy.

(2) the first acrylic acid and calcium carbonate are ball milled in a ball mill, so that the first acrylic acid is modified to calcium carbonate to obtain modified calcium carbonate;

The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene with an average molecular weight of 350,000 are uniformly mixed and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene.

The mass ratio of the first acrylic acid and calcium carbonate is 10:1, the mass ratio of the second acrylic acid and calcium carbonate is 100:1, and the mass ratio of polypropylene copolymer and calcium carbonate is 1:2;

The ball milling conditions of the first acrylic acid and calcium carbonate in the ball mill are as follows: the ball milling speed range is 500r/min, the mass of the ball: the bulk volume ratio of the treated material is 10:1, and the ball milling time is 900min.

(3) After uniformly mixing the modified homopolypropylene and the calcium carbonate-modified copolymerized polypropylene, they are uniformly mixed by ball milling at -100° C. to obtain a polypropylene mixture.

The mass ratio of modified homopolymer polypropylene to calcium carbonate modified copolymer polypropylene is 10:1;

The ball milling mixing conditions of the modified homopolypropylene and the calcium carbonate modified copolymer polypropylene are as follows: the ball milling speed is 500r/min, and the ball milling time is 100min.

(4) After ball milling, raise the temperature of the polypropylene mixture to normal temperature, then mix the polypropylene mixture with the β crystal nucleating agent evenly, and finally send it into a twin-screw extruder for melt co-extrusion to obtain a composite polypropylene material .

The mass ratio of the amount of β crystal form nucleating agent to the polypropylene mixture is 0.5:100.

Example 3

(1) After mixing homopolypropylene with an average molecular weight of 450,000, modified monomers and antioxidants, they are first sent to a banbury mixer for banburying treatment, then irradiated by an electron beam accelerator, and finally sent to a double Extrude after kneading by a screw extruder to obtain modified homopolypropylene.

Antioxidant is 1010, and the mass ratio of its consumption and homopolypropylene is 0.1:100;

The ratio of the amount of modified monomer to the amount of homopolypropylene is 100mmol:100g, and the modified monomer is a mixture of HDDA and TPGDA with a molar ratio of 2:1;

The conditions of banburying treatment are: 60 minutes at 180°C;

The conditions of the irradiation treatment are as follows: 50min under the irradiation intensity of 5kGy.

(2) the first acrylic acid and calcium carbonate are ball milled in a ball mill, so that the first acrylic acid is modified to calcium carbonate to obtain modified calcium carbonate;

The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene with an average molecular weight of 350,000 are uniformly mixed and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene.

The mass ratio of the first acrylic acid and calcium carbonate is 1:1, the mass ratio of the second acrylic acid and calcium carbonate is 1:5, and the mass ratio of polypropylene copolymer and calcium carbonate is 9:1;

The ball milling conditions of the first acrylic acid and calcium carbonate in the ball mill are as follows: the ball milling speed range is 300r/min, the mass of the ball: the bulk volume ratio of the treated material is 1:1, and the ball milling time is 100min.

(3) After uniformly mixing the modified homopolypropylene and the calcium carbonate-modified copolymerized polypropylene, they are uniformly mixed by ball milling at -50° C. to obtain a polypropylene mixture.

The mass ratio of modified homopolymer polypropylene to calcium carbonate modified copolymer polypropylene is 6:4;

The ball mill mixing conditions of modified homopolypropylene and calcium carbonate modified copolymer polypropylene are as follows: ball mill speed range 100r/min, ball mass: treatment material bulk volume ratio is 1:1, ball mill time is 20min.

(4) After ball milling, raise the temperature of the polypropylene mixture to normal temperature, then mix the polypropylene mixture with the β crystal nucleating agent evenly, and finally send it into a twin-screw extruder for melt co-extrusion to obtain a composite polypropylene material .

The mass ratio of the amount of β crystal nucleating agent to the polypropylene mixture is 0.15:100.

Example 4

This embodiment is basically the same as Example 3, except that the first part of acrylic acid and calcium carbonate is not mixed by ball milling, but only mixed by mechanical stirring, and the speed and time of stirring and mixing are the same as those of ball milling.

Example 5

This embodiment is basically the same as Embodiment 3, except that electron beam radiation is not performed.

Example 6

This example is basically the same as Example 1, except that the mass ratio of the modified homopolypropylene to the calcium carbonate-modified copolypropylene is 0.5:10.

Example 7

This example is basically the same as Example 2, except that the mass ratio of the modified homopolypropylene to the calcium carbonate-modified copolypropylene is 10:0.5.

Comparative example 1

This comparative example is basically the same as Example 3, except that the mixing of the modified homopolypropylene and the calcium carbonate-modified copolymerized polypropylene is carried out at normal temperature (25° C.).

Comparative example 2

This comparative example is basically the same as Example 3, the only difference being: the mixing of modified homopolypropylene and calcium carbonate modified copolymerized polypropylene is carried out at normal temperature (25°C);

The first part of acrylic acid and calcium carbonate is not mixed by ball milling, but only mixed by mechanical stirring, and the speed and time of stirring and mixing are the same as those of ball milling.

Experimental example

The rigidity (tensile strength and flexural modulus) and toughness (notched Charpy impact strength) of the composite polypropylene materials prepared in Examples 1-7 and Comparative Examples 1 and 2 were tested. Standard tensile measurements and bend tests are performed using a general purpose materials tester. Dumbbell specimens for tensile testing were tested according to ASTM D-638 (Type I) at a tensile speed of 50 mm/min and a gauge length of 50 mm. Static bending test measured at a crosshead speed of 2 mm/min using three-point bending set up according to ASTM D-790, with dimensions 127 x 12.7 x 3.0 mm ³ , simply supported with an impact tester according to ASTM D-256 Notched beam impact strength, the size of the sample is 63.5×12.7×33.0mm ³ , with a “V”-shaped notch. All mechanical tests were performed at room temperature. For each specimen, five measurements were performed and the average result calculated.

Record the test results in Table 1.

Table 1 Properties of each group of composite polypropylene materials

As can be seen from the test results in the above table, the composite polypropylene material prepared by each embodiment of the present application has higher rigidity and toughness, which is obviously better than that of Comparative Example 2, especially in Examples 1-3, and the rigidity and toughness are obviously higher. good. Comparing Example 3 and Comparative Example 1, it can be seen that the rigidity and toughness of Example 3 are significantly higher than that of Comparative Example, indicating that the ball milling of modified homopolypropylene and calcium carbonate modified copolymer polypropylene can significantly improve the The uniformity of the two mixtures improves the performance of the final composite material; comparing Example 4 with Example 3, its Charpy notched impact strength index is slightly worse, indicating that ball milling is used to make acrylic acid form chemical bonds with calcium carbonate , is conducive to improving the performance of the composite material obtained; Contrasting Example 5 with Example 3, the impact toughness of the tensile strength of Example 5 is slightly poor, illustrating that electron beam radiation treatment helps to improve the composite material obtained. Rigidity; Embodiment 6, embodiment 7 are compared with embodiment 1, 2 respectively, and the performance of embodiment 6 and 7 is slightly worse than the corresponding embodiment, illustrates the effect of modified homopolypropylene and calcium carbonate modified copolymerized polypropylene. Composite materials with better properties can be produced when the proportioning relationship is within the preferred range defined in this application.

In summary, the preparation method of the composite polypropylene material provided by this application is to treat the mixture of modified homopolypropylene and calcium carbonate modified copolymer polypropylene at a low temperature to make it close to the glass transition temperature. At this temperature, The material becomes brittle, and mixed ball milling can significantly improve the mixing properties of the two materials, and then melt extrusion can obtain a high rigidity and high toughness composite polypropylene material with good rigidity and toughness balance.

In the preferred scheme, banburying and irradiation treatment can change the molecular weight distribution of homopolypropylene and increase the average molecular weight, thereby further improving the rigid performance indicators of polypropylene (tensile strength, flexural strength, flexural modulus, etc.) , In addition, through electron beam radiation treatment, the surface activity of polypropylene can be increased, which is beneficial to the subsequent mixing performance with homopolypropylene materials.

In the preferred scheme, the first part of acrylic acid and calcium carbonate are mixed and ball milled, and the calcium carbonate is mechanochemically modified to form a chemical bond between acrylic acid and calcium carbonate, which can further improve the subsequent calcium carbonate in the modified material. Combination with polypropylene body; the first part and the second part of acrylic acid can improve the bonding strength between copolymerized polypropylene and homopolypropylene, so that the bonding of different components in the material can be improved.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A preparation method for composite polypropylene material, characterized in that, comprising: The modified homopolypropylene and the calcium carbonate modified copolymerized polypropylene are ball-milled and mixed at -100°C to -10°C to obtain a polypropylene mixture; Melting and extruding the polypropylene mixture and the β crystal form nucleating agent evenly after mixing; The modified homopolypropylene is a product of homopolypropylene modified by a modified monomer, and the modified monomer is at least one of 1,6-hexanediol diacrylate and tripropylene glycol diacrylate kind; The calcium carbonate-modified copolymerized polypropylene is a calcium carbonate-modified copolymerized polypropylene. 2. the preparation method of composite polypropylene material according to claim 1, is characterized in that, the mode of described modified monomer modification described homopolypropylene is: After mixing the homopolypropylene and the modified monomer, first perform banburying treatment and then perform irradiation treatment; Preferably, the conditions for banburying treatment are: 170°C-200°C for 30min-80min; Preferably, the conditions of the irradiation treatment are: treatment at an irradiation intensity of 0.5kGy-10kGy for 30min-80min. 3. according to the preparation method of the described composite polypropylene material of claim 1 or 2, it is characterized in that, the consumption ratio of described homopolypropylene and described modified monomer is 100g:1～100mmol; Preferably, an antioxidant is also used when the modified monomer modifies the homopolypropylene, and the mass ratio of the amount of the antioxidant to the homopolypropylene is 0.05-0.3:100 . 4. The preparation method of the composite polypropylene material according to claim 1, characterized in that, the mass ratio of the β crystal form nucleating agent to the polypropylene mixture is 0.01-0.5:100. 5. the preparation method of composite polypropylene material according to claim 1, is characterized in that, the mode of described calcium carbonate modification described polypropylene copolymer is: The first part of acrylic acid and the calcium carbonate are ball milled in a ball mill, so that the first part of acrylic acid is modified on the calcium carbonate to obtain modified calcium carbonate; The modified calcium carbonate, the second part of acrylic acid and the copolymerized polypropylene are uniformly mixed, and then melt-extruded to obtain the calcium carbonate-modified copolymerized polypropylene. 6. the preparation method of composite polypropylene material according to claim 5 is characterized in that, the mass ratio of described first acrylic acid and described calcium carbonate is 1～10:1～10, and described second acrylic acid The mass ratio to the calcium carbonate is 1-100:1-100, and the mass ratio of the copolymerized polypropylene to the calcium carbonate is 1-10:1-2. 7. the preparation method of composite polypropylene material according to claim 5 is characterized in that, the ball milling condition when described first acrylic acid and described calcium carbonate are ball milled in a ball mill is: ball milling speed 10r/min～500r /min, ball mass: the bulk volume ratio of the treated materials is 1-10:1-10, and the ball milling time is 30-900min. 8. the preparation method of composite polypropylene material according to claim 1 is characterized in that, the mass ratio of described modified homopolypropylene and described calcium carbonate modified copolymerized polypropylene is 1～10:1～10 . 9. The preparation method of the composite polypropylene material according to claim 1, characterized in that, the ball milling mixing condition of the modified homopolypropylene and the calcium carbonate modified copolymer polypropylene is: 10r/min～500r /min, the ball milling time is 1-100min. 10. A composite polypropylene material, characterized in that it is prepared by the preparation method according to any one of claims 1-9.