A method for preparing a polypropylene / polyamide composite material with improved compatibility

Abstract

The present invention relates to a method for preparing a polypropylene / polyamide composite material for improving compatibility, and belongs to the technical field of polymer materials. The present invention comprises polyamide, polypropylene, a compatibilizer, an antioxidant, a flame retardant, an antistatic agent, and an ultraviolet absorber, and after stirring and mixing, extruding and granulating through a twin-screw machine to obtain a polypropylene / polyamide composite material; the compatibilizer of the present invention is to subject polypropylene grafted maleic anhydride to plasma treatment, after vacuuming, passing through mercaptoethanol steam, and treating under voltage to obtain sulfhydryl-containing polypropylene grafted maleic anhydride immersed in an impregnation solution, adding a photoinitiator, and then distilling and removing DMF; the product after immersion is subjected to ultraviolet irradiation treatment to obtain; the impregnation solution of the present invention is stirred by allyl (cyclopentadienyl) nickel, 4-vinylbenzene boric acid pinesol ester, and DMF to obtain; the compatibilizer prepared by the present invention can effectively improve the mechanical properties and heat resistance of polypropylene / polyamide composite materials.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a method for preparing a polypropylene / polyamide composite material with improved compatibility. Background Art

[0002] Polyamide is a highly polar crystalline polymer with excellent mechanical properties, wear resistance and good processing and forming properties. However, its strong polarity makes it absorb water at a high rate and has poor dimensional stability, thus limiting its application in the field of engineering plastics. Polypropylene has the advantages of excellent tensile properties, non-absorbent, easy processing and low cost, but it also has the disadvantages of large molding shrinkage and easy brittle cracking at low temperatures. If polypropylene is blended with polyamide, the disadvantages of a single polymer can be overcome, but the polarity and crystal structure of the two are quite different, resulting in incompatibility of the blend, which affects the performance of the mixture.

[0003] Chinese patent CN112538260A: discloses a glass fiber reinforced polypropylene / polyamide composite material and its preparation method, belonging to the field of polypropylene / polyamide composite materials. The glass fiber reinforced polypropylene / polyamide composite material comprises the following components by weight: 20-25 parts of polypropylene, 65-70 parts of polyamide, 30-35 parts of short glass fibers, 10-20 parts of compatibilizer, 0.2-0.4 parts of curing agent and 0.2-0.4 parts of antioxidant; the compatibilizer comprises PP-g-MAH, epoxy resin and oxazoline; the curing agent is one or two of diethyltetramethylimidazole and epoxy-imidazole complex.

[0004] Chinese patent CN104194147A: discloses a multi-scale fiber-reinforced polypropylene / polyamide composite material, comprising the following raw materials in weight percentage: 5-95% long fiber-reinforced polypropylene resin masterbatch and 5-95% short fiber-reinforced polypropylene / polyamide diluted resin.

[0005] Chinese patent CN107987453A: relates to the field of polymer material technology, specifically to an injection molding grade polypropylene / polyamide micro-foam composite material and a preparation method thereof, wherein the injection molding grade polypropylene / polyamide micro-foam composite material is made of a raw material composition, the raw material composition comprising: 49 to 78 parts by weight of polypropylene, 15 to 30 parts by weight of polyamide, 1 to 3 parts by weight of a chemical foaming agent, 5 to 15 parts by weight of a compatibilizer, 2 to 6 parts by weight of magnesium oxide, 2 to 12 parts by weight of isocyanate, 0.1 to 0.38 parts by weight of an aminosilane coupling agent, 0.2 to 0.4 parts by weight of an antioxidant, 0.5 to 1 parts by weight of a lubricant, and 0 to 2 parts by weight of an optional auxiliary agent.

[0006] The existing technology not only requires a large amount of compatibilizer to be added, but also has an insignificant volume-increasing effect, and it is difficult to simultaneously strengthen and toughen the composite material. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a method for preparing a polypropylene / polyamide composite material with improved compatibility, and the operating steps are as follows:

[0008] S1: Add 35-45 parts of polyamide, 15-20 parts of polypropylene, 1-5 parts of compatibilizer, 0.1-0.5 parts of antioxidant, 0.01-0.1 parts of flame retardant, 0.01-0.1 parts of antistatic agent, and 0.01-0.1 parts of ultraviolet absorber into a stirring tank, and mix for 5-15 minutes to obtain a mixed material;

[0009] S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material;

[0010] The extrusion temperature of the twin-screw machine is 220-240° C., the screw speed is 300-500 r / min, and the vacuum degree is -0.06 to -0.08 MPa.

[0011] The polyamide is one of polyamide 6 (PA6), polyamide 66 (PA66), polyamide 11 (PA11), polyamide 12 (PA12), and polyamide 610 (PA610).

[0012] The polypropylene is one of homopolymer polypropylene, block copolymer polypropylene and random copolymer polypropylene.

[0013] The antioxidant is one of antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant 2246, antioxidant 702, antioxidant 300 and antioxidant DNP.

[0014] The flame retardant is one of tetrabromobisphenol A, hexabromocyclododecane, tris(2-chloroethyl) phosphate, tris(2-chloropropyl) phosphate and tris(2,3-dichloropropyl) phosphate.

[0015] The antistatic agent is one of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate, ethoxylated alkylamine, ethoxylated lauryl amide, and glyceryl monostearate.

[0016] The ultraviolet absorber is one of o-hydroxybenzoic acid phenyl ester, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone.

[0017] The preparation method of the compatibilizer is:

[0018] A1 plasma treatment: The polypropylene grafted with maleic anhydride is subjected to plasma treatment. After vacuuming to 100-150Pa, mercaptoethanol vapor is introduced and treated for 60-120 seconds at a power of 50-100KW and a voltage of 380V;

[0019] A2: Immersion treatment: Immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 60-80° C. for 50-100 minutes, then remove DMF by distillation;

[0020] A3 UV irradiation treatment: The product is subjected to UV irradiation treatment with a wavelength of 300 nm, a power of 500-1000 W, and a time of 10-30 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride.

[0021] The preparation method of the impregnation solution is:

[0022] According to weight, 0.08-0.16 parts of allyl(cyclopentadienyl)nickel CAS: 12107-46-9, 11-23 parts of 4-vinylbenzeneboronic acid pinesol ester CAS: 870004-04-9, and 100-140 parts of DMF are stirred at 40-50° C. for 1-3 hours to obtain an impregnation solution.

[0023] The photoinitiator is one of photoinitiator 1173, photoinitiator TPO, photoinitiator 819, photoinitiator benzophenone, and photoinitiator ITX.

[0024] Reaction mechanism

[0025] The compatibilizer is prepared by reacting thiol-containing polypropylene grafted with maleic anhydride with allyl (cyclopentadienyl) nickel and 4-vinylbenzene boric acid pinesol ester.

[0026] 1. Thiol click chemistry addition reaction

[0027] Thiol (-SH) is a highly active functional group that can undergo addition reactions with a variety of compounds. In the present invention, the thiol undergoes a click chemistry reaction with allyl (cyclopentadienyl) nickel and the olefin of 4-vinylbenzene boronic acid pinesol ester to form a stable thioether bond. This reaction has high selectivity and high efficiency and can be carried out quickly under mild conditions.

[0028] The mercapto group reacts with allyl (cyclopentadienyl) nickel to form polypropylene grafted maleic anhydride containing a nickelocene structure through an addition reaction. Nickelocene is an organic metal complex, and the cyclopentadienyl group in its structure forms a stable coordination bond with nickel, which can enhance the interaction between polymer chains.

[0029] The mercapto group reacts with 4-vinylbenzene boronic acid pinesol ester to generate polypropylene grafted maleic anhydride containing a borate structure. Borate is a highly polar functional group that can significantly improve the polarity and hydrophilicity of the polymer.

[0030] 2. Mechanisms to improve compatibility

[0031] Enhanced interfacial interaction: The introduction of nickelocene and borate esters gives polypropylene molecular chains more polar functional groups. These polar functional groups can form stronger hydrogen bonds or dipole interactions with polar groups on polyamide molecular chains, thereby enhancing the interfacial interaction between the two polymers.

[0032] Improved dispersibility: Due to the presence of nickelocene and borate, the spatial configuration and polarity of the polypropylene molecular chain are optimized, making it easier to disperse in the polyamide matrix. The uniformly dispersed polypropylene phase can more effectively transfer stress and improve the mechanical properties of the composite material.

[0033] Reduced phase separation: By introducing nickelocene and borate, the compatibility between polypropylene and polyamide is significantly improved, reducing the phase separation phenomenon. This helps to form a uniform composite material and improve its comprehensive performance.

[0034] Technical Effects

[0035] The present invention discloses a method for preparing a polypropylene / polyamide composite material with improved compatibility. Compared with the prior art, the present invention has the following significant effects:

[0036] 1. Improved thermal stability: The modified composite material exhibits better thermal stability in high temperature environment, and the heat deformation temperature is increased, which is suitable for a wider range of industrial applications.

[0037] 2. Optimization of processing performance: The fluidity and processing performance of the modified material have also been improved, making it perform better in injection molding, extrusion and other processing technologies.

[0038] 3. The compatibilizer prepared by the present invention can effectively improve the mechanical properties and heat resistance of polypropylene / polyamide composite materials. DETAILED DESCRIPTION

[0039] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with the embodiments and comparative examples, and the test results are shown in Table 1:

[0040] 1. Notched impact strength test: refer to ISO179-1-2010 for testing, the sample size is 80×8×4mm, and the notch type is type A;

[0041] 2. Heat deformation temperature test: refer to ISO75-2-2013 for testing, the sample size is 80×8×4mm.

[0042] Example 1

[0043] A method for preparing a polypropylene / polyamide composite material with improved compatibility, the operating steps of which are:

[0044] S1: Add 35 g of polyamide, 15 g of polypropylene, 1 g of compatibilizer, 0.1 g of antioxidant, 0.01 g of flame retardant, 0.01 g of antistatic agent, and 0.01 g of ultraviolet absorber into a stirring tank, and mix for 5 min to obtain a mixed material;

[0045] S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material;

[0046] The extrusion temperature of the twin-screw machine is 220° C., the screw speed is 300 r / min, and the vacuum degree is -0.06 MPa.

[0047] The polyamide is polyamide 6 (PA6).

[0048] The polypropylene is homopolymer polypropylene.

[0049] The antioxidant is antioxidant 1010.

[0050] The flame retardant is tetrabromobisphenol A.

[0051] The antistatic agent is octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

[0052] The ultraviolet absorber is phenyl o-hydroxybenzoate.

[0053] The preparation method of the compatibilizer is:

[0054] A1 plasma treatment: The polypropylene grafted with maleic anhydride was subjected to plasma treatment. After vacuuming to 100 Pa, mercaptoethanol vapor was introduced and treated for 60 seconds at a power of 50 KW and a voltage of 380 V.

[0055] A2 immersion treatment: immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 60° C. for 50 minutes, then distill and remove DMF;

[0056] A3 UV irradiation treatment: The product was subjected to UV irradiation treatment with a wavelength of 300 nm, a power of 500 W, and a time of 10 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride.

[0057] The preparation method of the impregnation solution is:

[0058] 0.08 g of allyl(cyclopentadienyl)nickel CAS: 12107-46-9, 11 g of 4-vinylbenzeneboronic acid pinesol ester CAS: 870004-04-9, and 100 g of DMF were stirred at 40° C. for 1 hour to obtain an impregnation solution.

[0059] The photoinitiator is photoinitiator 1173.

[0060] Example 2

[0061] A method for preparing a polypropylene / polyamide composite material with improved compatibility, the operating steps of which are:

[0062] S1: According to mass parts, 38g polyamide, 16g polypropylene, 2g compatibilizer, 0.2g antioxidant, 0.05g flame retardant, 0.05g antistatic agent, and 0.05g ultraviolet absorber were added to a stirring tank and mixed for 8min to obtain a mixed material;

[0063] S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material;

[0064] The extrusion temperature of the twin-screw machine is 225° C., the screw speed is 350 r / min, and the vacuum degree is -0.07 MPa.

[0065] The polyamide is polyamide 66 (PA66).

[0066] The polypropylene is block copolymer polypropylene.

[0067] The antioxidant is antioxidant 1076.

[0068] The flame retardant is hexabromocyclododecane.

[0069] The antistatic agent is ethoxylated alkylamine.

[0070] The ultraviolet absorber is 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0071] The preparation method of the compatibilizer is:

[0072] A1 plasma treatment: The polypropylene grafted with maleic anhydride was subjected to plasma treatment. After vacuuming to 110 Pa, mercaptoethanol vapor was introduced and treated for 80 seconds at a power of 60 KW and a voltage of 380 V.

[0073] A2 immersion treatment: immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 65° C. for 70 minutes, then distill and remove DMF;

[0074] A3 UV irradiation treatment: The product was subjected to UV irradiation treatment with a wavelength of 300 nm, a power of 600 W, and a time of 15 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride.

[0075] The preparation method of the impregnation solution is:

[0076] 0.11 g of allyl(cyclopentadienyl)nickel CAS: 12107-46-9, 16 g of 4-vinylbenzeneboronic acid pinesol ester CAS: 870004-04-9, and 110 g of DMF were stirred at 45° C. for 2 h to obtain an impregnation solution.

[0077] The photoinitiator is photoinitiator TPO.

[0078] Example 3

[0079] A method for preparing a polypropylene / polyamide composite material with improved compatibility, the operating steps of which are:

[0080] S1: According to the mass fraction, 43 g of polyamide, 18 g of polypropylene, 4 g of compatibilizer, 0.4 g of antioxidant, 0.08 g of flame retardant, 0.08 g of antistatic agent, and 0.08 g of ultraviolet absorber were added into a stirring tank and mixed for 13 min to obtain a mixed material;

[0081] S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material;

[0082] The extrusion temperature of the twin-screw machine is 235° C., the screw speed is 450 r / min, and the vacuum degree is -0.07 MPa.

[0083] The polyamide is polyamide 11 (PA11).

[0084] The polypropylene is block copolymer polypropylene.

[0085] The antioxidant is antioxidant 264.

[0086] The flame retardant is tris(2-chloroethyl) phosphate.

[0087] The antistatic agent is ethoxylated lauryl amide.

[0088] The ultraviolet absorber is 2,4-dihydroxybenzophenone.

[0089] The preparation method of the compatibilizer is:

[0090] A1 plasma treatment: The polypropylene grafted with maleic anhydride was subjected to plasma treatment. After vacuuming to 140Pa, mercaptoethanol vapor was introduced and treated for 100 seconds at a power of 90KW and a voltage of 380V;

[0091] A2 immersion treatment: immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 75°C for 90 minutes, then distill and remove DMF;

[0092] A3 UV irradiation treatment: The product was subjected to UV irradiation treatment with a wavelength of 300 nm, a power of 900 W, and a time of 25 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride.

[0093] The preparation method of the impregnation solution is:

[0094] 0.13 g of allyl(cyclopentadienyl)nickel CAS: 12107-46-9, 21 g of 4-vinylbenzeneboronic acid pinesol ester CAS: 870004-04-9, and 130 g of DMF were stirred at 45° C. for 2 h to obtain an impregnation solution.

[0095] The photoinitiator is photoinitiator 819.

[0096] Example 4

[0097] A method for preparing a polypropylene / polyamide composite material with improved compatibility, the operating steps of which are:

[0098] S1: According to the mass fraction, 45 g of polyamide, 20 g of polypropylene, 5 g of compatibilizer, 0.5 g of antioxidant, 0.1 g of flame retardant, 0.1 g of antistatic agent, and 0.1 g of ultraviolet absorber were added into a stirring tank and mixed for 15 min to obtain a mixed material;

[0099] S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material;

[0100] The extrusion temperature of the twin-screw machine is 240° C., the screw speed is 500 r / min, and the vacuum degree is -0.08 MPa.

[0101] The polyamide is polyamide 610 (PA610).

[0102] The polypropylene is random copolymer polypropylene.

[0103] The antioxidant is antioxidant DNP.

[0104] The flame retardant is tris(2,3-dichloropropyl) phosphate.

[0105] The antistatic agent is glyceryl monostearate.

[0106] The ultraviolet absorber is 2-hydroxy-4-n-octyloxybenzophenone.

[0107] The preparation method of the compatibilizer is:

[0108] A1 plasma treatment: The polypropylene grafted with maleic anhydride was subjected to plasma treatment. After vacuuming to 150Pa, mercaptoethanol vapor was introduced and treated for 120 seconds at a power of 100KW and a voltage of 380V;

[0109] A2: Immersion treatment: immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 80° C. for 100 minutes, then distill and remove DMF;

[0110] A3 UV irradiation treatment: The product was subjected to UV irradiation treatment with a wavelength of 300 nm, a power of 1000 W, and a time of 30 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride.

[0111] The preparation method of the impregnation solution is:

[0112] 0.16 g of allyl(cyclopentadienyl)nickel CAS: 12107-46-9, 23 g of 4-vinylbenzeneboronic acid pinesol ester CAS: 870004-04-9, and 140 g of DMF were stirred at 50° C. for 3 h to obtain an impregnation solution.

[0113] The photoinitiator is photoinitiator ITX.

[0114] Comparative Example 1

[0115] The process is not immersed in the immersion liquid, and the other aspects are the same as those in Example 1.

[0116] Comparative Example 2

[0117] Allyl(cyclopentadienyl)nickel was not added, and the rest was the same as in Example 1.

[0118] Comparative Example 3

[0119] The other steps were the same as in Example 1 except that 4-vinylbenzene boric acid pinesol ester was not added.

[0120] Table 1

[0121] <![CDATA[Notched impact strength / kJ / m 2 > Heat deformation temperature / ℃ Example 1 7.8 137 Example 2 8.1 140 Example 3 8.3 140 Example 4 8.6 143 Comparative Example 1 6.7 119 Comparative Example 2 7.2 131 Comparative Example 3 7.5 133

[0122] Through the data analysis of the above examples and comparative examples, the compatibilizer prepared by the present invention can effectively improve the mechanical properties and heat resistance of the polypropylene / polyamide composite material.

[0123] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a polypropylene / polyamide composite material with improved compatibility, the operating steps of which are: S1: Add 35-45 parts of polyamide, 15-20 parts of polypropylene, 1-5 parts of compatibilizer, 0.1-0.5 parts of antioxidant, 0.01-0.1 parts of flame retardant, 0.01-0.1 parts of antistatic agent, and 0.01-0.1 parts of ultraviolet absorber into a stirring tank, and mix for 5-15 minutes to obtain a mixed material; S2: extruding and granulating the mixed material through a twin-screw machine to obtain a polypropylene / polyamide composite material; The extrusion temperature of the twin-screw machine is 220-240°C, the screw speed is 300-500r / min, and the vacuum degree is -0.06 to -0.08MPa; The compatibilizer is prepared by reacting thiol-containing polypropylene grafted with maleic anhydride with allyl (cyclopentadienyl) nickel and 4-vinylbenzene boric acid pinesol ester; The preparation method of the compatibilizer is: A1 plasma treatment: The polypropylene grafted with maleic anhydride is subjected to plasma treatment. After vacuuming to 100-150Pa, mercaptoethanol vapor is introduced and treated for 60-120 seconds at a power of 50-100KW and a voltage of 380V; A2: Immersion treatment: Immerse the thiol-containing polypropylene grafted with maleic anhydride treated in step A1 in an immersion solution, add a photoinitiator, and stir at 60-80° C. for 50-100 minutes, then remove DMF by distillation; A3 UV irradiation treatment: The product is subjected to UV irradiation treatment at a wavelength of 300 nm, a power of 500-1000 W, and a time of 10-30 min, and finally dried to obtain modified polypropylene grafted with maleic anhydride; The preparation method of the impregnation solution is: According to weight, 0.08-0.16 parts of allyl(cyclopentadienyl)nickel, 11-23 parts of 4-vinylbenzeneboronic acid pinesol ester, and 100-140 parts of DMF are stirred at 40-50° C. for 1-3 hours to obtain an impregnation solution.

2. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The polyamide is one of polyamide 6, polyamide 66, polyamide 11, polyamide 12 and polyamide 610.

3. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The polypropylene is one of homopolymer polypropylene, block copolymer polypropylene and random copolymer polypropylene.

4. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The antioxidant is one of antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant 2246, antioxidant 702, antioxidant 300 and antioxidant DNP.

5. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The flame retardant is one of tetrabromobisphenol A, hexabromocyclododecane, tris(2-chloroethyl) phosphate, tris(2-chloropropyl) phosphate and tris(2,3-dichloropropyl) phosphate.

6. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The antistatic agent is one of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate, ethoxylated alkylamine, ethoxylated lauryl amide, and glyceryl monostearate.

7. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The ultraviolet absorber is one of o-hydroxybenzoic acid phenyl ester, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone.

8. The method for preparing a polypropylene / polyamide composite material with improved compatibility according to claim 1, characterized in that: The photoinitiator is one of photoinitiator 1173, photoinitiator TPO, photoinitiator 819, photoinitiator benzophenone, and photoinitiator ITX.