Beta crystal form polypropylene composite material and preparation method thereof

Abstract

The invention discloses a beta crystal form polypropylene composite material and a preparation method thereof. The beta crystal form polypropylene composite material comprises the following raw materials: polypropylene and polythiophene, polythiophene is added into polypropylene, polypropylene can be induced to form more beta crystal form polypropylene, the induction efficiency of polythiophene is high, the addition amount of polythiophene is low, and the problem that a polymer type nucleating agent is poor in nucleation induction efficiency is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polypropylene composite materials, and particularly relates to a beta crystal polypropylene composite material and a preparation method thereof. BACKGROUND

[0002] In 1954, Natta synthesized polypropylene with high stereoregularity for the first time, and then polypropylene realized industrial production, which opened a new era of polymer science and engineering. Good thermal performance and mechanical performance make polypropylene widely used in many fields, such as injection molding, film and fiber production.

[0003] Under different crystallization conditions, polypropylene can form α, β, γ and other crystal forms and smectic structures, among which α crystal form is the most common and stable crystal form. The β crystal form belongs to the trigonal system and is a metastable state in thermodynamics, which is easy to undergo phase transition during heating or stretching. Under high pressure conditions, γ crystal form is preferentially formed.

[0004] Compared with α crystal form and other crystal forms of polypropylene, β crystal form of polypropylene has the advantages of low elastic modulus and yield strength, high impact strength and heat distortion temperature, good toughness and ductility under high speed stretching conditions; on the other hand, β crystal can also improve the porosity of polypropylene and improve the printability and paintability of polypropylene products. Therefore, how to obtain β crystal form polypropylene or improve the content of β crystal in polypropylene has become one of the hotspots in the research of material science in recent years.

[0005] Adding “β nucleating agent” to induce the formation of β crystal is a simple, highly repeatable and currently the only industrialized method to obtain high content of β crystal form polypropylene. Since a dye γ-quinacridone (E3B) was studied as a polypropylene β nucleating agent, polypropylene β nucleating agent has not only made certain achievements in basic research, but also shown great value in commercial application. The existing β nucleating agents on the market include: fused ring compounds with quasi-planar structure, aromatic amine compounds, complex of alkaline earth metal and dibasic acid, rare earth compounds, polymer nucleating agent and complex nucleating agent. Small molecule nucleating agents have certain shortcomings, for example, they are easy to agglomerate and have poor dispersibility in the polymer processing process, and some nucleating agents need surface treatment or addition of dispersant to obtain better dispersion effect, while others are more likely to deposit.

[0006] There are significant differences between polymeric nucleating agents and small-molecule nucleating agents. First, the former have a much larger relative molecular weight than the latter, and their compatibility with the polymer matrix is ​​also better than that of small-molecule nucleating agents. Second, polymers such as polystyrene and liquid crystal polymers are mostly amorphous polymers, and their nucleation mechanism cannot be explained by the lattice size matching theory used for small-molecule induced nucleation. Therefore, the research on polymeric β-nucleating agents is not only of great theoretical significance but also has potential application prospects. For polymeric nucleating agents, because the relative molecular weight of macromolecular nucleating agents is much greater than that of small-molecule nucleating agents, the nucleating agent content is relatively high. However, the β-nucleation induction efficiency of polymers is generally low, and the addition amount is usually greater than 1%. Summary of the Invention

[0007] In response to the above-mentioned deficiencies in the prior art, a β-crystalline polypropylene composite material is provided. By adding polythiophene to polypropylene, polypropylene can be induced to form more β-crystalline polypropylene. Polythiophene has high induction efficiency and low addition amount, which solves the problem of poor nucleation induction efficiency of polymer-type nucleating agents.

[0008] The object of the present invention is to provide a β-crystal polypropylene composite material, comprising the following raw materials: polypropylene and polythiophene.

[0009] In some embodiments of the present invention, the polythiophene is selected from polymers of any of the following structures:

[0010] 、 、 、 ;

[0011] Among them, the number average molecular weight is 4.7~17.3KDa.

[0012] In some embodiments of the present invention, the structure of the polythiophene is as follows:

[0013] ;

[0014] Among them, the number average molecular weight is 6.5~8.9KDa.

[0015] In some embodiments of the present invention, the structure of the polythiophene is as follows:

[0016] ;

[0017] Among them, the number average molecular weight is 9.7~17.3KDa.

[0018] In some embodiments of the present invention, the structure of the polythiophene is as follows:

[0019] ;

[0020] Among them, the number average molecular weight is 4.7~13.8KDa.

[0021] In some embodiments of the present invention, the structure of the polythiophene is as follows:

[0022] ;

[0023] Among them, the number average molecular weight is 7.5~13.5KDa.

[0024] In some embodiments of the present invention, the mole percentage of the hexylthiophene segment of the polythiophene chain segment is 80% to 97.1%.

[0025] In some embodiments of the present invention, the isotacticity of the polythiophene is ≥80%.

[0026] In some embodiments of the present invention, the isotacticity of the polythiophene is ≥90%.

[0027] In some embodiments of the present invention, the amount of the polythiophene is 300 ppm to 1000 ppm of the polypropylene, calculated as a percentage by mass.

[0028] In some embodiments of the present invention, the amount of the polythiophene is 500 ppm to 800 ppm of the polypropylene, calculated as a percentage by mass.

[0029] In some embodiments of the present invention, the crystallization temperature of the β-crystalline polypropylene composite material is 118-119°C.

[0030] In some embodiments of the present invention, the β-crystalline polypropylene composite material has a crystallinity of 38.8-51.3%.

[0031] In some embodiments of the present invention, the content of β-crystalline polypropylene in the β-crystalline polypropylene composite material is 6.4-53.5% of the total crystalline material, calculated as a percentage by mass.

[0032] Another object of the present invention is to provide a method for preparing the β-crystalline polypropylene composite material, comprising the following steps:

[0033] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0034] S2. Mix polythiophene and tetrachloroethane, heat to 120~160℃, dissolve to obtain a polythiophene solution;

[0035] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, a poor solvent was added, and the precipitation was performed to obtain a matrix material;

[0036] S4. Blending the base material with the remaining polypropylene powder, melt extruding to obtain the beta crystal form polypropylene composite material.

[0037] In some embodiments of the present application, in S2, the amount of the part of the polypropylene powder is not more than 1% of the total mass of the polypropylene powder.

[0038] In some embodiments of the present application, in S3, the poor solvent is selected from at least one of methanol and ethanol.

[0039] In some embodiments of the present application, in S3, the volume ratio of the homogeneous solution to the poor solvent is 1:100-500.

[0040] In some embodiments of the present application, in S4, the temperature of the melt extrusion is 180-230℃.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] The present application adds polythiophene into polypropylene, and the polythiophene has a high induction effect, can induce polypropylene to form more beta crystal form polypropylene, and has the advantages of high induction efficiency and low addition amount, thereby solving the problem of poor nucleation induction efficiency of polymer type nucleating agent. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 DSC second heating spectrum of the beta crystal form polypropylene composite material of Example 5.

[0044] Figure 2 DSC second heating spectrum of the beta crystal form polypropylene composite material of Comparative Example 1. DETAILED DESCRIPTION

[0045] In order to enable the personnel in the technical field to better understand the technical solutions in the present application, the technical solutions of the present application will be described clearly and completely in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the personnel in the field without making creative efforts should belong to the scope of protection of the present application.

[0046] Example 1

[0047] The present embodiment provides a beta crystal form polypropylene composite material, and the specific preparation steps are as follows:

[0048] S1. Grinding polypropylene into powder, mixing part of the polypropylene powder with tetrachloroethane, heating to 120-160℃, dissolving to obtain a polypropylene solution;

[0049] S2. Mixing polythiophene having an isotacticity of 91% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0050] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, methanol was added, the volume ratio of the homogeneous solution to methanol was 1:100, precipitated, and the precipitate was obtained to obtain a matrix material;

[0051] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0052] Wherein, the amount of polythiophene used is 300ppm of polypropylene in terms of mass percentage;

[0053] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0054] The structure of the polythiophene is shown below:

[0055] ;

[0056] Among them, the number average molecular weight Mn is 8.9 KDa, PDI is 2.61, x=4.7 mmol%, y=95.3 mmol%.

[0057] Example 2

[0058] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0059] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0060] S2. Mixing polythiophene having an isotacticity of 92% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0061] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, ethanol was added, the volume ratio of the homogeneous solution to ethanol was 1:500, precipitated, and the precipitate was obtained to obtain a matrix material;

[0062] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0063] Wherein, the amount of polythiophene used is 800ppm of polypropylene in terms of mass percentage;

[0064] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0065] The structure of the polythiophene is shown below:

[0066] ;

[0067] Among them, the number average molecular weight Mn is 6.5 KDa, PDI is 2.67, x=8.3 mmol%, y=91.7 mmol%.

[0068] Example 3

[0069] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0070] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0071] S2. Mixing 80% isotactic polythiophene with tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0072] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, methanol was added, the volume ratio of the homogeneous solution to methanol was 1:300, precipitated, and the precipitate was obtained to obtain a matrix material;

[0073] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0074] Wherein, the amount of polythiophene used is 500ppm of polypropylene in terms of mass percentage;

[0075] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0076] The structure of the polythiophene is shown below:

[0077] ;

[0078] Among them, the number average molecular weight Mn is 9.7 KDa, PDI is 3.51, x=5 mmol%, y=95 mmol%.

[0079] Example 4

[0080] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0081] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0082] S2. Mixing polythiophene having an isotacticity of 84.5% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0083] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, ethanol was added, the volume ratio of the homogeneous solution to ethanol was 1:200, precipitated, and the precipitate was obtained to obtain a matrix material;

[0084] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0085] Wherein, the amount of polythiophene used is 1000ppm of polypropylene in terms of mass percentage;

[0086] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0087] The structure of the polythiophene is shown below:

[0088] ;

[0089] Among them, the number average molecular weight Mn is 17.3 KDa, PDI is 3.82, x=11.8 mmol%, y=88.2 mmol%.

[0090] Example 5

[0091] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0092] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0093] S2. Mixing polythiophene having an isotacticity of 85% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0094] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, methanol was added, the volume ratio of the homogeneous solution to methanol was 1:250, precipitated, and the precipitate was obtained to obtain a matrix material;

[0095] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0096] Wherein, the amount of polythiophene used is 600ppm of polypropylene in terms of mass percentage;

[0097] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0098] The structure of the polythiophene is shown below:

[0099] ;

[0100] Among them, the number average molecular weight Mn is 13.8 KDa, PDI is 2.2, x=4.3 mmol%, y=95.7 mmol%.

[0101] Example 6

[0102] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0103] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0104] S2. Mixing polythiophene having an isotacticity of 83% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0105] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, ethanol was added, the volume ratio of the homogeneous solution to ethanol was 1:400, precipitated, and the precipitate was obtained to obtain a matrix material;

[0106] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0107] Wherein, the amount of polythiophene used is 700ppm of polypropylene in terms of mass percentage;

[0108] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0109] The structure of the polythiophene is shown below:

[0110] ;

[0111] Among them, the number average molecular weight Mn is 4.7 KDa, PDI is 1.3, x=20 mmol%, y=80 mmol%.

[0112] Example 7

[0113] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0114] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0115] S2. Mixing polythiophene having an isotacticity of 87% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0116] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, methanol was added, the volume ratio of the homogeneous solution to methanol was 1:350, precipitated, and the precipitate was obtained to obtain a matrix material;

[0117] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0118] Wherein, the amount of polythiophene used is 900ppm of polypropylene in terms of mass percentage;

[0119] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0120] The structure of the polythiophene is shown below:

[0121] ;

[0122] Among them, the number average molecular weight Mn is 13.5KKDa, PDI is 2.5, x=2.5mmol%, y=97.5mmol%.

[0123] Example 8

[0124] This embodiment provides a β-crystalline polypropylene composite material, and the specific preparation steps are as follows:

[0125] S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution;

[0126] S2. Mixing polythiophene having an isotacticity of 89% and tetrachloroethane, heating to 120-160°C, and dissolving to obtain a polythiophene solution;

[0127] S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, ethanol was added, the volume ratio of the homogeneous solution to ethanol was 1:450, precipitated, and the precipitate was obtained to obtain a matrix material;

[0128] S4. The matrix material is blended with the remaining polypropylene powder and melt-extruded at 180-230 ° C to obtain a β-crystalline polypropylene composite material;

[0129] Wherein, the amount of polythiophene used is 400ppm of polypropylene in terms of mass percentage;

[0130] The amount of partial polypropylene powder used is 0.1% of the total mass of polypropylene powder;

[0131] The structure of the polythiophene is shown below:

[0132] ;

[0133] Among them, the number average molecular weight Mn is 7.5KKDa, PDI is 2.1, x=13.9mmol%, y=86.1mmol%.

[0134] Comparative Example 1

[0135] No polythiophene was added, and the polypropylene powder of any one of Examples 1 to 5 was used.

[0136] Performance testing:

[0137] The performance tests were conducted on the β-crystal polypropylene composite materials of Examples 1 to 8 and the polypropylene of Comparative Example 1. The results are shown in Table 1.

[0138] Table 1. Properties of β-crystalline polypropylene composites and polypropylene.

[0139]

[0140] As shown in Table 1, by comparing Examples 1 to 8 with Comparative Example 1, the present invention adds polythiophene to polypropylene. Polythiophene has a high efficiency induction effect and can induce polypropylene to form more β-crystalline polypropylene. Polythiophene has the advantages of high induction efficiency and low addition amount, which solves the problem of poor nucleation induction efficiency of polymer type nucleating agents.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the specification of this application, technicians can still modify or replace the specific implementation methods of the present invention with equivalents, but these modifications or changes do not depart from the scope of protection of the pending claims of the present application.

Claims

1. A β-crystalline polypropylene composite material, characterized in that: The invention comprises the following raw materials: polypropylene and polythiophene.

2. The β-crystalline polypropylene composite material according to claim 1, wherein The polythiophene is selected from polymers of any of the following structures: 、 、 、 Among them, the number average molecular weight is 4.7~17.3KDa.

3. The β-crystalline polypropylene composite material according to claim 2, wherein: The mole percentage of the hexylthiophene chain segment of the polythiophene is 80% to 97.1% of the polythiophene chain segment.

4. The β-crystalline polypropylene composite material according to claim 1, wherein The isotacticity of the polythiophene is ≥80%.

5. The β-crystalline polypropylene composite material according to claim 1, wherein Calculated by mass percentage, the amount of the polythiophene is 300ppm to 1000ppm of the polypropylene.

6. The β-crystalline polypropylene composite material according to any one of claims 1 to 5, wherein The crystallization temperature of the β-crystalline polypropylene composite material is 118-119°C.

7. The β-crystalline polypropylene composite material according to any one of claims 1 to 5, wherein The crystallinity of the β-crystalline polypropylene composite material is 38.8-51.3%.

8. The β-crystalline polypropylene composite material according to any one of claims 1 to 5, wherein Calculated by mass percentage, the content of beta-crystalline polypropylene in the beta-crystalline polypropylene composite material is 6.4-53.5% of the total crystalline matter.

9. The method for preparing the β-crystalline polypropylene composite material according to any one of claims 1 to 5, characterized in that: The steps include: S1. Grind polypropylene into powder, take part of the polypropylene powder, mix with tetrachloroethane, heat to 120~160℃, dissolve to obtain a polypropylene solution; S2. Mix polythiophene and tetrachloroethane, heat to 120~160℃, dissolve to obtain a polythiophene solution; S3. The polypropylene solution and the polythiophene solution were mixed into a homogeneous solution, a poor solvent was added, and the precipitation was performed to obtain a matrix material; S4. Blending the matrix material with the remaining polypropylene powder, and melt-extruded to obtain a β-crystalline polypropylene composite material.

10. The method for preparing the β-crystalline polypropylene composite material according to claim 9, wherein: The amount of the partial polypropylene powder is no more than 1% of the total mass of the polypropylene powder; And / or, the temperature of the melt extrusion is 180-230°C.

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