Anhydride-containing modified polypropylene composite material and preparation method and application thereof

Abstract

The present application belongs to the field of polymers, and relates to anhydride-containing modified polypropylene composite material and a preparation method and application thereof. The anhydride-containing modified polypropylene composite material comprises a propylene-based continuous phase, a rubber phase dispersed in the propylene-based continuous phase, and a grafted phase derived from an anhydride monomer and an alkenyl-containing functional monomer; wherein the D50 of the grafted phase is less than 170 nm, the anhydride-containing modified polypropylene composite material has a flexural modulus of 200-1000 MPa; the xylene-soluble content of the anhydride-containing modified polypropylene composite material is 10-55 wt%; the content of structural units in a grafted state in the anhydride-containing modified polypropylene composite material is 0.3-5 wt%, and the content of structural units derived from the anhydride monomer and in a grafted state is 0.05-2 wt%. The anhydride-containing modified polypropylene composite material of the present application can balance mechanical properties and electrical properties at a relatively high working temperature, and is suitable for high-temperature and high-operation-field-strength working conditions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polymers, and in particular relates to an anhydride-containing modified polypropylene composite material, a preparation method of the anhydride-containing modified polypropylene composite material, and an application of the anhydride-containing modified polypropylene composite material. BACKGROUND

[0002] With the sustained and rapid development of China's economy, the people's living standards continue to improve, and the demand for electricity is also growing rapidly. Solving the problem of the channel for power energy delivery and delivering large-capacity electric energy to users is one of the major problems to be solved in the development of electricity. In order to solve this problem, China has established the basic development direction of building and developing ultra-high voltage and high-capacity AC and DC power transmission systems. In the development of extruded plastic insulated cables, the most important and key problem is the development of cable insulation materials. Traditional extruded DC cables generally use cross-linked polyethylene (XLPE) as the cable insulation material.

[0003] The main method for treating waste XLPE cable insulation is incineration, which not only wastes energy but also produces greenhouse gases and other environmental problems. In addition, XLPE cables need to be cross-linked and degassed during the production process, which produces harmful gases and other pollutants, and also wastes a lot of energy. Therefore, how to improve the environmental friendliness and compatibility of power cable insulation materials has become an important problem in the development of power cable insulation materials. In recent years, in order to meet the requirements of environmental protection and sustainable development, many institutions and scholars have begun to research new recyclable non-cross-linked polyolefin cable insulation materials.

[0004] Polypropylene-based materials have the advantages of high operating temperature and high breakdown field strength as cable insulation, and also have space charge suppression characteristics and recyclability, which has become the focus of the development of non-cross-linked polyolefin insulation materials. By blending polypropylene and polyolefin elastomer, and blending polypropylene and ethylene propylene copolymer, the brittleness of polypropylene is effectively improved, and the good thermal and electrical properties of polypropylene are retained. Nano-doping is an effective way to improve the electrical insulation performance of polypropylene materials. However, the problem of easy agglomeration of nanoparticles leading to a decrease in insulation performance limits the widespread application of this method in practical engineering.

[0005] Therefore, it is necessary to find a new type of polypropylene material with stable performance and easy preparation to adapt to higher temperature and high field strength applications. SUMMARY

[0006] The present application aims to overcome the defects of the prior art, and provides an anhydride-containing modified polypropylene composite material which can balance mechanical properties and electrical properties at a higher working temperature and is suitable for high-temperature and high-operating field intensity conditions.

[0007] The first aspect of the present application provides an anhydride-containing modified polypropylene composite material, which comprises a propylene-based continuous phase, a rubber phase dispersed in the propylene-based continuous phase, and a grafted phase derived from an anhydride monomer and an alkenyl-containing functional monomer; wherein the D50 of the grafted phase is less than 170 nm.

[0008] The xylene-soluble content of the anhydride-containing modified polypropylene composite material is 10-55 wt%, preferably 15-45 wt%, and more preferably 20-40 wt%, based on the total weight of the anhydride-containing modified polypropylene composite material; the content of structural units in a grafted state in the anhydride-containing modified polypropylene composite material is 0.3-5 wt%, preferably 0.7-3 wt%, and the content of structural units derived from an anhydride monomer and in a grafted state is 0.05-2 wt%, preferably 0.2-0.5 wt%; the anhydride-containing modified polypropylene composite material has a flexural modulus of 200-1000 MPa.

[0009] The second aspect of the present application provides a preparation method of the above-mentioned anhydride-containing modified polypropylene composite material, which comprises the following steps: blending a modified polypropylene (A) and a low-modulus polypropylene (B) to obtain the anhydride-containing modified polypropylene composite material, wherein the modified polypropylene (A) is a polypropylene (A) grafted with an alkenyl-containing functional monomer and optionally grafted with an anhydride monomer, and the low-modulus polypropylene (B) is an unmodified low-modulus polypropylene and / or a low-modulus polypropylene grafted with an alkenyl-containing functional monomer and optionally grafted with an anhydride monomer.

[0010] The third aspect of the present application provides an application of the above-mentioned anhydride-containing modified polypropylene composite material.

[0011] The anhydride-containing modified polypropylene composite material of the present application can balance mechanical properties and electrical properties at a higher working temperature and is suitable for high-temperature and high-operating field intensity conditions. Compared with a polypropylene material obtained by in-kettle alloying, the polypropylene material is mechanically blended with a low-modulus polypropylene, so that the structure of the product is more diverse and flexible to control, thereby obtaining better performance. Compared with a nano-doping technology, the anhydride monomer and the alkenyl-containing functional monomer polymer introduced by dispersion grafting can form a uniformly distributed nano-scale dispersed phase, i.e. an organic nanoparticle, in the composite material, thereby avoiding the problems of inorganic nanoparticles, such as difficult addition and dispersion. In addition, compared with a material with added small-molecule additives, the grafted modified polypropylene material of the present application avoids performance degradation caused by small-molecule migration, and thus has better stability.

[0012] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0013] The exemplary embodiments of the present application will be described in more detail by way of specific examples with reference to the accompanying drawings.

[0014] Figure 1 AFM image of the product in Example 1, wherein the bright white part indicated by the circle is the styrene-maleic anhydride graft phase, the black part is the rubber phase, and the other part is the continuous phase.

[0015] Figure 2 Microstructure image of the product in Example 1 under 20000 times electron microscope, wherein the spherical dispersed phase is the styrene-maleic anhydride graft phase.

[0016] Figure 3 Microstructure image of the product in Example 2 under 20000 times electron microscope.

[0017] Figure 4 Microstructure image of the product in Example 3 under 20000 times electron microscope.

[0018] Figure 5 Microstructure image of the product in Comparative Example 3 under 20000 times electron microscope.

[0019] Figure 6 Microstructure image of the product in Comparative Example 3 under 20000 times electron microscope after etching, wherein the black part is the rubber phase.

[0020] Figure 7 Microstructure image of the product in Comparative Example 4 under 20000 times electron microscope.

[0021] Figure 8 Microstructure image of the product in Comparative Example 5 under 20000 times electron microscope. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application will be described in detail below. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0023] The present application provides an anhydride-containing modified polypropylene composite material, which comprises a propylene-based continuous phase, a rubber phase dispersed in the propylene-based continuous phase, and a graft phase derived from an anhydride monomer and an alkenyl-containing functional monomer; wherein the D50 of the graft phase is less than 170 nm, preferably 10-150 nm, and more preferably 55-110 nm.

[0024] The acid anhydride-containing modified polypropylene composite has a xylene soluble content of 10 to 55 wt%, preferably 15 to 45 wt%, more preferably 20 to 40 wt%, based on the total weight of the acid anhydride-containing modified polypropylene composite; the content of structural units in the grafted state in the acid anhydride-containing modified polypropylene composite is 0.3 to 5 wt%, preferably 0.7 to 3 wt%, wherein the content of structural units derived from the acid anhydride monomer and in the grafted state is 0.05 to 2 wt%, preferably 0.2 to 0.5 wt%; the acid anhydride-containing modified polypropylene composite has a flexural modulus of 200 to 1000 MPa, preferably a flexural modulus of 200 to 700 MPa, more preferably a flexural modulus of 250 to 600 MPa.

[0025] In the present application, the acid anhydride-containing modified polypropylene composite is a phase-separated structure. The "continuous phase" is known to those skilled in the art and refers to the matrix portion, the "rubbery phase" refers to the soft xylene-soluble portion, and the "grafted phase" is formed by structural units derived from the acid anhydride monomer and the alkenyl-containing functional monomer, which can all come from grafted homopolymerized or copolymerized polypropylene or can partially come from grafted low-modulus polypropylene. Therefore, the structural units derived from the acid anhydride monomer and / or the alkenyl-containing functional monomer in the grafted state refer to structural units derived from the acid anhydride monomer and / or the alkenyl-containing functional monomer that are covalently linked (grafted) to the polypropylene and optionally the low-modulus polypropylene. The multi-phase structure can be observed by atomic force microscopy, in which the black portion observed by atomic force microscopy is the rubbery phase, the bright white portion is the grafted phase, and the other portion is the continuous phase. The grafted phase can also be directly observed by electron microscopy (dispersed phase in the electron microscopy image).

[0026] According to the present application, preferably, the acid anhydride-containing modified polypropylene composite has at least one of the following characteristics: a melt flow rate at 230°C under a load of 2.16 kg of 0.5 to 15 g / 10 min, preferably 1 to 10 g / 10 min, and further preferably 1.2 to 6 g / 10 min; an elongation at break of ≥ 200%, preferably an elongation at break of ≥ 300%; a tensile strength of more than 5 MPa, preferably 10 to 25 MPa.

[0027] According to the present application, preferably, the acid anhydride-containing modified polypropylene composite has at least one of the following characteristics:

[0028] - the acid anhydride-containing modified polypropylene composite has a maximum operating temperature of ≥ 90°C, preferably 100 to 160°C, and more preferably 110 to 140°C;

[0029] - the anhydride-containing modified polypropylene composite has a breakdown field strength Eg at 110°C of ≥ 285 kV / mm, preferably 290 to 800 kV / mm, more preferably 310 to 750 kV / mm; for example 320 kV / mm, 330 kV / mm, 340 kV / mm, 350 kV / mm, 400 kV / mm, 450 kV / mm, 500 kV / mm, 550 kV / mm, 600 kV / mm, 650 kV / mm, 700 kV / mm;

[0030] - the anhydride-containing modified polypropylene composite has a DC volume resistivity p at 110°C, 40 kV / mm field strength of ≥ 2.0 x 10 vg 13 Ω m, preferably 4.0 x 10 13 Ω m to 1.0 x 10 20 Ω m;

[0031] - the anhydride-containing modified polypropylene composite has a dielectric constant at 110°C, 50 Hz of greater than 2.0, preferably 2.1 to 2.5.

[0032] According to the present application, the anhydride monomer can be selected from anhydrides having at least one olefinic unsaturation; preferably, the anhydride monomer is selected from maleic anhydride and / or itaconic anhydride; further preferably, the anhydride monomer is maleic anhydride.

[0033] The alkenyl group in the alkenyl-containing functional monomer of the present application is used for grafting with polypropylene / low modulus polypropylene, and thus, any alkenyl-containing functional monomer having an alkenyl group at a reactive site is suitable for use in the present application.

[0034] Specifically, the alkenyl-containing functional monomer is selected from at least one of the monomers having the structure shown in Formula 1,

[0035]

[0036] In Formula 1, R b , R c , R d are each independently selected from H, substituted or unsubstituted alkyl; R a is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted ester, substituted or unsubstituted carboxyl, substituted or unsubstituted cycloalkyl or heterocyclic group, cyano, substituted or unsubstituted silyl group.

[0037] According to a preferred embodiment of the present application, R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6 alkyl; R a ​Selected from substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C1-C 20 Alkoxy, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C1-C 20 Ester group, substituted or unsubstituted C1-C 20 Carboxyl group, substituted or unsubstituted C3-C 20 Cycloalkyl or heterocyclic, cyano, substituted or unsubstituted C3-C 20 Silyl group; the substituted group is halogen, hydroxyl, amino, C1-C 12 Alkyl, C3-C6 cycloalkyl, C1-C 12 alkoxy groups, C1-C 12 Acyloxy group.

[0038] According to a more preferred embodiment of the present invention, wherein R b R c R d Each is independently selected from H, substituted or unsubstituted C1-C6 alkyl groups;

[0039] R a Selected from the groups shown in Formula 2, Formula 3, Formula 4, Formula 5, Formula 6, combinations of the groups shown in Formula 6 and Formula 7, and heterocyclic groups;

[0040]

[0041] In Equation 2, R 4 -R 8 Each is independently selected from H, halogen, hydroxyl, amino, phosphate group, sulfonic acid group, substituted or unsubstituted C1-C. 12 Alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester group, substituted or unsubstituted C1-C 12 The substituted amino group, wherein the substituted group is selected from halogen, hydroxyl, amino, phosphate, sulfonic acid, C1-C 12 Alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy groups, C1-C 12 ester group, C1-C 12 The amino group; preferably, R 4 -R 8 Each is independently selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy;

[0042]

[0043] In Equation 3, R4-R 10 Each is independently selected from H, halogen, hydroxyl, amino, phosphate group, sulfonic acid group, substituted or unsubstituted C1-C. 12 Alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester group, substituted or unsubstituted C1-C 12 The substituted amino group, wherein the substituted group is selected from halogen, hydroxyl, amino, phosphate, sulfonic acid, C1-C 12 Alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy groups, C1-C 12 ester group, C1-C 12 The amino group; preferably, R4-R 10 Each of the groups is independently selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituted group is selected from halogen, hydroxyl, amino, C1-C6 alkyl, C1-C6 alkoxy;

[0044]

[0045] In Equation 4, R4'-R 10 Each group is independently selected from H, halogen, hydroxyl, amino, phosphate, sulfonic acid, substituted or unsubstituted C1-C. 12 Alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester group, substituted or unsubstituted C1-C 12 The substituted amino group, wherein the substituted group is selected from halogen, hydroxyl, amino, phosphate, sulfonic acid, C1-C 12 Alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy groups, C1-C 12 ester group, C1-C 12 The amino group; preferably, R4'-R 10 Each of the following is independently selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, wherein the substituted group is selected from halogen, hydroxyl, amino, C1-C6 alkyl, C1-C6 alkoxy;

[0046]

[0047] In Equation 5, R', R”, and R”' are each independently selected from substituted or unsubstituted C1-C. 12 Straight-chain alkyl, substituted or unsubstituted C3-C 12 Branched alkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 The acyloxy group; preferably, R1 is a C2-C6 alkenyl group, preferably a monounsaturated alkenyl group; R2, R3, and R4 are each independently selected from substituted or unsubstituted C1-C6 straight-chain alkyl groups, substituted or unsubstituted C3-C6 branched alkyl groups, substituted or unsubstituted C1-C6 alkoxy groups, and substituted or unsubstituted C1-C6 acyloxy groups;

[0048]

[0049] In Equation 6, R m Selected from the following groups, substituted or unsubstituted: C1-C 20 Straight-chain alkyl, C3-C 20 Branched alkyl, C3-C 12 cycloalkyl, C3-C 12 Epoxyalkyl, C3-C 12 Epoxyalkylalkyl, wherein the substituted group is selected from at least one of halogen, amino and hydroxyl groups;

[0050] The heterocyclic group is selected from imidazole, pyrazol, carbazole, pyrrolidone, pyridinyl, piperidinyl, caprolactam, pyrazinyl, thiazolyl, purine, morpholino, and oxazolino.

[0051] According to a specific embodiment of the present invention, the alkenyl-containing functional monomer is an aromatic olefin monomer, wherein the aromatic olefin monomer is selected from at least one of styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene, monosubstituted or polysubstituted styrene, monosubstituted or polysubstituted α-methylstyrene, monosubstituted or polysubstituted 1-vinylnaphthalene, and monosubstituted or polysubstituted 2-vinylnaphthalene; the substituted group is preferably selected from at least one of halogen, hydroxyl, amino, phosphate group, sulfonic acid group, C1-C8 straight-chain alkyl, C3-C8 branched alkyl or cycloalkyl, C1-C6 straight-chain alkoxy, C3-C8 branched alkoxy or cyclic alkoxy, C1-C8 straight-chain ester group, C3-C8 branched ester group or cyclic ester group, C1-C8 straight-chain amino group, and C3-C8 branched amino group or cyclic amino group; preferably, the aromatic olefin monomer is selected from at least one of styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, and 4-methylstyrene.

[0052] According to one embodiment of the present application, the alkenyl group-containing functional monomer is an alkenyl group-containing silane-based monomer selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, vinyltri-t-butoxysilane, vinyltriacetoxysilane, methylvinyl dimethoxysilane, ethylvinyl diethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, allyltriisopropoxysilane, vinyltris(β-methoxyethoxy)silane, allyl tris(β-methoxyethoxy)silane, allyltri-t-butoxysilane, allyltriacetoxysilane, methylallyl dimethoxysilane, and ethylallyl diethoxysilane.

[0053] According to one embodiment of the present application, the alkenyl group-containing functional monomer is an acrylate-based monomer and optionally an acrylic monomer. Preferably, the acrylate-based monomer is selected from at least one of methyl (meth)acrylate, sec-butyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isooctyl (meth)acrylate, dodecyl (meth)acrylate, coconut oil (meth)acrylate, stearyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and glycidyl (meth)acrylate. Preferably, the acrylic monomer is selected from at least one of acrylic acid, methacrylic acid, and 2-ethylacrylic acid.

[0054] In the present application, the C3-C 12 Epoxyalkylalkyl means an epoxyalkyl group-substituted alkyl group having 3 to 12 carbon atoms, for example, an epoxyethane group-substituted methyl group.

[0055] In the present application, the structural unit derived from the acrylic monomer can be present or absent together with the structural unit derived from the acrylate monomer. Preferably, the molar ratio of the structural unit derived from the acrylate monomer to the structural unit derived from the acrylic monomer is 1:0 to 2, preferably 1:0.125 to 1.

[0056] According to one embodiment of the present application, the alkenyl group-containing functional monomer is an alkenyl group-containing heterocyclic compound. The alkenyl group-containing heterocyclic monomer of the present application can be any alkenyl group-containing heterocyclic compound capable of being polymerized by a free radical, and can be selected from at least one of an alkenyl group-substituted imidazole, an alkenyl group-substituted pyrazole, an alkenyl group-substituted carbazole, an alkenyl group-substituted pyrrolidine, an alkenyl group-substituted pyridine or pyridine salt, an alkenyl group-substituted piperidine, an alkenyl group-substituted caprolactam, an alkenyl group-substituted pyrazine, an alkenyl group-substituted thiazole, an alkenyl group-substituted purine, an alkenyl group-substituted morpholine, and an alkenyl group-substituted oxazoline; preferably, the alkenyl group-containing heterocyclic monomer is a mono-alkenyl group-containing heterocyclic monomer.

[0057] In particular, the alkenyl group-containing heterocyclic monomer can be selected from at least one of 1-vinylimidazole, 2-methyl-l-vinylimidazole, N-allylimidazole, 1-vinylpyrazole, 3-methyl-l-vinylpyrazole, vinylcarbazole, N-vinylpyrrolidone, 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, vinylpyridine N-oxide, vinylpyridine salt, vinylpiperidine, N-vinylcaprolactam, 2-vinylpyrazine, N-vinylpiperazine, 4-methyl-5-vinylthiazole, N-vinylpurine, vinylmorpholine, and vinyl oxazoline.

[0058] Further, the alkenyl group-containing polymerizable monomer can be selected from at least one of vinyl acetate, styrene, a-methylstyrene, a (meth)acrylate, a vinyl alkyl ether, vinyl pyrrolidone, vinyl pyridine, vinyl imidazole, and acrylonitrile; the (meth)acrylate can be at least one of methyl (meth)acrylate, ethyl (meth)acrylate, and glycidyl (meth)acrylate; preferably, the alkenyl group-containing polymerizable monomer can be selected from vinyl acetate, styrene, and a-methylstyrene; further preferably, the alkenyl group-containing polymerizable monomer is styrene.

[0059] According to the present application, preferably, the anhydride-containing modified polypropylene composite material comprises modified polypropylene (A) which is polypropylene grafted with an alkenyl functional monomer and optionally an anhydride monomer, and low modulus polypropylene (B) which is unmodified low modulus polypropylene, and / or low modulus polypropylene grafted with an alkenyl functional monomer and optionally an anhydride monomer. That is, the modified polypropylene (A) can be polypropylene grafted with an alkenyl functional monomer, or polypropylene grafted with both an alkenyl functional monomer and an anhydride monomer, the low modulus polypropylene (B) can be unmodified low modulus polypropylene, or low modulus polypropylene grafted with an alkenyl functional monomer, or low modulus polypropylene grafted with both an alkenyl functional monomer and an anhydride monomer, and mixtures thereof. When the modified polypropylene (A) is polypropylene grafted with an alkenyl functional monomer, the low modulus polypropylene (B) must be low modulus polypropylene grafted with both an alkenyl functional monomer and an anhydride monomer. When the modified polypropylene (A) is polypropylene grafted with both an alkenyl functional monomer and an anhydride monomer, the low modulus polypropylene (B) can be unmodified low modulus polypropylene, or low modulus polypropylene grafted with an alkenyl functional monomer, or low modulus polypropylene grafted with both an alkenyl functional monomer and an anhydride monomer. The present application does not have special requirements for the grafting component content of each raw material, as long as the total grafting amount of the anhydride-containing modified polypropylene composite material meets the above requirements.

[0060] Preferably, the content of the polypropylene (A) is 20-80 wt%, preferably 30-70 wt%, more preferably 35-65 wt%, and the content of the low modulus polypropylene (B) is 20-80 wt%, preferably 30-70 wt%, more preferably 35-65 wt%, based on the total weight of the anhydride-containing modified polypropylene composite material.

[0061] According to a preferred embodiment of the present application, the anhydride-containing modified polypropylene composite material is prepared by blending the modified polypropylene (A) and the low modulus polypropylene (B).

[0062] In the three-phase structure of the anhydride-containing modified polypropylene composite material of the present application, the modified polypropylene (A) provides at least a propylene-based continuous phase and a grafted phase; and the low modulus polypropylene (B) provides a propylene-based continuous phase and a rubber phase, and optionally a grafted phase.

[0063] In the present application, the polypropylene (A) grafted and modified with the functional monomer containing an alkenyl group includes structural units derived from homo- or co-polypropylene, and structural units derived from the functional monomer containing an alkenyl group, and optionally structural units derived from an anhydride monomer; the content of the structural units in the grafted state in the modified polypropylene (A) is 0.1 to 10 wt%, preferably 1 to 5 wt%, based on the weight of the modified polypropylene (A).

[0064] In the present application, the "structural unit" means that it is a part of the polypropylene (A) and its form is not limited. Specifically, the "structural unit derived from co-polypropylene" refers to the product formed from co-polypropylene, which includes both "radical" form and "polymer" form. The "structural unit derived from (maleic) anhydride monomer" refers to the product formed from (maleic) anhydride, which includes both "radical" form and "monomer" form, and also includes "polymer" form. The "structural unit derived from the alkenyl-containing polymer monomer" refers to the product formed from the alkenyl-containing polymer monomer, which includes both "radical" form and "monomer" form, and also includes "polymer" form. The "structural unit" can be a repeating unit or a non-repeating independent unit.

[0065] In the present application, the "comonomer" of the co-polypropylene is known to those skilled in the art, which refers to the monomer copolymerized with propylene.

[0066] According to a preferred embodiment of the present application, the homo- or co-polypropylene has at least one of the following characteristics: the comonomer content is 0 to 15 mol%, preferably 0 to 12 mol%, and more preferably 0 to 8 mol%; the melt flow rate at 230°C under a load of 2.16 kg is 1 to 10 g / 10 min, preferably 2 to 5 g / 10 min; the melting temperature Tm is 110 to 180°C, and further preferably 120 to 170°C; the weight average molecular weight is 20 x 10 4 4 g / mol; the flexural modulus is 500 to 2000 MPa, preferably 600 to 1700 MPa; the elongation at break is ≥ 200%, preferably the elongation at break is ≥ 300%; the tensile strength is greater than 5 MPa, and preferably 10 to 40 MPa.

[0067] ​According to a preferred embodiment of the present application, the comonomer of the copolymerized polypropylene is at least one selected from C2-C8 alpha-olefins other than propylene; preferably, the comonomer of the copolymerized polypropylene is at least one selected from ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene and 1-octene; further preferably, the comonomer of the copolymerized polypropylene is ethylene and / or 1-butene; the comonomer content is 0.1-15 mol%, preferably 0.1-12 mol%, and more preferably 0.1-8 mol%, based on the total moles of monomers. The copolymerized polypropylene according to the present application is preferably a porous particulate or powdery resin.

[0068] The homopolymerized or copolymerized polypropylene according to the present application can be any commercially available polypropylene powder suitable for the present application, or can be produced by the polymerization process described in Chinese Patents CN102453180B, CN101490096B, CN102816269B, CN102816270B, etc.

[0069] The concept of "low modulus polypropylene" according to the present application is well known to those skilled in the art, and preferably refers to an ethylene-propylene copolymer having a flexural modulus of less than 300 MPa; in particular, the ethylene-propylene impact copolymer comprises a propylene homopolymer and / or a propylene random copolymer matrix component (1) as a matrix phase, and another propylene copolymer component (2) dispersed therein as a dispersed phase, the propylene copolymer component comprising one or more ethylene or higher alpha-olefin comonomers. In the propylene random copolymer, the comonomers are randomly distributed along the main chain of the propylene polymer. Preferably, the propylene copolymer (2) dispersed in the homopolymer or copolymer matrix (1) of the low modulus polypropylene is substantially amorphous. The term "substantially amorphous" means herein that the propylene copolymer (2) has a lower crystallinity than the homopolymer or copolymer matrix (1).

[0070] The low modulus polypropylene can have a sea-island structure or a bi-continuous structure. Preferably, the copolymerized polypropylene according to the present application is a multiphase propylene copolymer prepared in situ in a reactor by existing processes.

[0071] According to the present application, preferably, the low modulus polypropylene has at least one of the following characteristics: a comonomer content of 8-25 wt%, preferably 10-22 wt%; a xylene solubles content of 18-75 wt%, preferably 30-70 wt%, more preferably 30-67 wt%; a melt flow rate at 230℃ under a load of 2.16 kg of 0.1-15 g / 10 min, preferably 0.2-7 g / 10 min; a melting temperature Tm of 120-165℃, further preferably 125-150℃; a flexural modulus of 10-300 MPa, preferably 15-250 MPa; a comonomer content in the xylene solubles of 10-50 wt%, preferably 20-35 wt%; a ratio of the intrinsic viscosity of the xylene solubles to the low modulus polypropylene of 0.5-3, preferably 0.8-1.3.

[0072] The low modulus polypropylene described in the present application includes, but is not limited to, any commercially available polypropylene powder and granules suitable for the present application, and can also be produced by the polymerization processes described in Chinese Patents CN1069908C, CN1049932C, CN1108315C, CN1117610C, CN1132865C and CN102020733B, etc. Commonly used polymerization processes include the Spheripol process of Basell Company, the Hypol process of Mitsui Petrochemical Company, the Borstar PP process of Borealis Company, the Unipol process of DOW Chemical Company, the Innovene gas phase process of INEOS (formerly BP-Amoco) Company, etc.

[0073] In the present application, when the grafting condition is not specified, the "low modulus polypropylene" generally refers to a low modulus polypropylene that is not grafted (i.e., not modified).

[0074] According to the present application, preferably, the content of the structural units in the grafted state in the low modulus polypropylene (B) is 0-5 wt%, preferably 0.5-2.5 wt%, based on the weight of the low modulus polypropylene (B).

[0075] The present application also provides a preparation method of the anhydride-containing modified polypropylene composite material, comprising the following steps: blending the modified polypropylene (A) with the low modulus polypropylene (B) to obtain the anhydride-containing modified polypropylene composite material, wherein the modified polypropylene (A) is a polypropylene (A) grafted and modified with an alkenyl functional monomer and optionally an anhydride monomer, and the low modulus polypropylene (B) is a low modulus polypropylene that is not modified and / or a low modulus polypropylene grafted and modified with an alkenyl functional monomer and optionally an anhydride monomer;

[0076] Preferably, the polypropylene (A) is used in an amount of 20-80 wt%, preferably 30-70 wt%, more preferably 35-65 wt%, and the low modulus polypropylene (B) is used in an amount of 20-80 wt%, preferably 30-70 wt%, more preferably 35-65 wt%, based on the total weight of the anhydride-containing modified polypropylene composite material.

[0077] According to a preferred embodiment of the present application, the preparation method comprises the following steps:

[0078] S1: grafting reaction of a reaction mixture A comprising a homo- or co-polypropylene and a first grafting monomer in the presence of an inert gas to obtain a modified polypropylene;

[0079] Optionally, grafting reaction of a reaction mixture B comprising a low modulus polypropylene and a second grafting monomer in the presence of an inert gas to obtain a modified low modulus polypropylene;

[0080] S2: mixing, extruding and granulating the modified polypropylene, the unmodified low modulus polypropylene and / or the modified low modulus polypropylene and optional additives to obtain the anhydride-containing modified polypropylene composite material;

[0081] The first grafting monomer and the second grafting monomer are each independently an alkenyl functional monomer and optionally an anhydride monomer. The grafting monomers are determined according to the target grafting product.

[0082] Preferably, the grafting point is initiated by a free radical initiator and the grafting reaction is further carried out. In this case, the reaction mixture A and the reaction mixture B each independently further comprise a free radical initiator.

[0083] Preferably, the peroxide free radical initiator is selected from at least one of dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, dodecanoyl peroxide, tert-butyl benzene percarboxylate, diisopropyl peroxydicarbonate, tert-butyl peroxy(2-ethylhexanoate) and dicyclohexyl peroxydicarbonate; and the azo free radical initiator is preferably azobis-isobutyronitrile and / or azobis-isohexylnitrile.

[0084] More preferably, the grafting point is initiated by a peroxide free radical initiator and the grafting reaction is further carried out.

[0085] In addition, the grafting reaction of the present application can also be carried out by the methods described in CN106543369A, CN104499281A, CN102108112A, CN109251270A, CN1884326A and CN101492517B.

[0086] In the case of satisfying the above product characteristics, the amounts of the components in the grafting reaction are not particularly limited, and specifically, the mass ratio of the radical initiator to the total mass of the grafting monomers in the reaction system can be 0.1 to 10:100, preferably 0.5 to 6:100. The total mass of the first grafting monomers to the mass of the homopolymerized or copolymerized polypropylene can be 0.5 to 35:100, preferably 2 to 30:100, and further preferably 2.5 to 20:100. The total mass of the second grafting monomers to the mass of the low modulus polypropylene can be 0.5 to 15:100, preferably 2 to 10:100. When the grafting monomers include an alkenyl group-containing functional monomer and an acid anhydride monomer, the mass ratio of the alkenyl group-containing functional monomer to the acid anhydride monomer can be 0.5 to 10:1, preferably 2 to 8:1.

[0087] The process conditions of the grafting reaction are not particularly limited, and preferably, the grafting reaction is a solid phase grafting reaction, and specifically, the temperature of the grafting reaction is 30 to 130°C, preferably 60 to 120°C, and the time is 0.5 to 10 hours, preferably 1 to 6 hours.

[0088] In the present application, the "reaction mixture" includes all materials added to the grafting reaction system, which can be added at one time or at different stages of the reaction.

[0089] The reaction mixture A and the reaction mixture B of the present application can each independently include a dispersant, which is preferably water or an aqueous sodium chloride solution. The mass amount of the dispersant is preferably 50 to 300% of the mass of the polypropylene.

[0090] The reaction mixture A and the reaction mixture B of the present application can each independently include an interfacial agent, which is an organic solvent having a swelling effect on polyolefins, and preferably at least one of the following organic solvents having a swelling effect on polypropylene: ether solvents, ketone solvents, aromatic hydrocarbon solvents, and alkane solvents; more preferably at least one of the following organic solvents: chlorobenzene, polychlorobenzene, C6 or more alkanes or cycloalkanes, benzene, C1-C4 alkyl-substituted benzene, C2-C6 fatty ethers, C3-C6 fatty ketones, decalin; and further preferably at least one of the following organic solvents: benzene, toluene, xylene, chlorobenzene, tetrahydrofuran, diethyl ether, acetone, hexane, cyclohexane, decalin, and heptane. The mass content of the interfacial agent is preferably 1 to 30% of the mass of the polypropylene, and further preferably 10 to 25%.

[0091] The reaction mixture A and the reaction mixture B of the present application can each independently further comprise an organic solvent as a solvent for dissolving the solid radical initiator, which preferably comprises at least one of C2-C5 alcohols, C2-C4 ethers and C3-C5 ketones, more preferably at least one of C2-C4 alcohols, C2-C3 ethers and C3-C5 ketones, and most preferably at least one of ethanol, diethyl ether and acetone. The mass content of the organic solvent is preferably 1-35% of the mass of the polypropylene.

[0092] According to a preferred embodiment of the present application, the preparation method comprises the following steps:

[0093] a. placing the homo- or co-polypropylene into a closed reactor and performing inert gas replacement;

[0094] b. adding the radical initiator and the first grafting monomer into the closed reactor and stirring to mix;

[0095] c. optionally adding an interfacial agent and optionally allowing the reaction system to swell;

[0096] d. optionally adding a dispersing agent, heating the reaction system to a grafting reaction temperature and performing grafting reaction;

[0097] e. after the reaction is completed, optionally performing filtration and drying to obtain the modified polypropylene;

[0098] f. mixing the modified polypropylene with the ungrafted and / or grafted low modulus polypropylene and optional adjuvants, melt-extruding and granulating to obtain the anhydride-containing modified polypropylene composite material;

[0099] wherein the preparation method of the grafted low modulus polypropylene comprises the following steps:

[0100] i. placing the low modulus polypropylene into a closed reactor and performing inert gas replacement;

[0101] ii. adding the radical initiator and the second grafting monomer into the closed reactor and stirring to mix;

[0102] iii. optionally adding an interfacial agent and optionally allowing the reaction system to swell;

[0103] iv. optionally adding a dispersing agent, heating the reaction system to a grafting reaction temperature and performing grafting reaction;

[0104] v. after the reaction is completed, optionally performing filtration and drying to obtain the modified low modulus polypropylene.

[0105] Specifically, the preparation method comprises the following steps:

[0106] a. Put the homo- or co-polypropylene into a closed reactor, and perform inert gas replacement;

[0107] b. Add the radical initiator and the first grafting monomer into the closed reactor, and mix under stirring;

[0108] c. Add the interfacial agent 0-30 parts, and optionally swell the reaction system at 20-60°C for 0-24 hours;

[0109] d. Add the dispersing agent 0-300 parts, and heat the system to the grafting polymerization temperature 30-130°C, and react for 0.5-10 hours;

[0110] e. After the reaction is completed, optionally perform filtration (in the case of using the aqueous dispersing agent), and after drying, obtain the modified polypropylene;

[0111] f. Weigh and mix the modified polypropylene with the ungrafted and / or grafted low modulus polypropylene and optional adjuvants in proportion, and use a twin-screw extruder to mix and granulate at the melting temperature 180-230°C and the screw rotation speed 30-600 rpm, to obtain the anhydride-containing modified polypropylene composite material;

[0112] The preparation method of the grafted low modulus polypropylene comprises the following steps:

[0113] i. Put the low modulus polypropylene into a closed reactor, and perform inert gas replacement;

[0114] ii. Add the radical initiator and the second grafting monomer into the closed reactor, and mix under stirring;

[0115] iii. Add the interfacial agent 0-30 parts, and optionally swell the reaction system at 20-60°C for 0-24 hours;

[0116] iv. Add the dispersing agent 0-300 parts, and heat the system to the grafting polymerization temperature 30-130°C, and react for 0.5-10 hours;

[0117] v. After the reaction is completed, optionally perform filtration (in the case of using the aqueous dispersing agent), and after drying, obtain the modified low modulus polypropylene.

[0118] According to another preferred embodiment of the present application, the preparation method comprises the following steps:

[0119] a. Put the homo- or co-polypropylene into a closed reactor, and perform inert gas replacement;

[0120] b. Mix the organic solvent and the radical initiator, and add into the closed reactor;

[0121] c. Remove the organic solvent;

[0122] d. adding a first grafting monomer, optionally adding an interfacial agent, and optionally swelling the reaction system;

[0123] e. optionally adding a dispersing agent, heating the reaction system to a grafting reaction temperature, and performing a grafting reaction;

[0124] f. after the reaction is completed, optionally performing filtration, and drying to obtain the modified polypropylene;

[0125] g. weighing and mixing the modified polypropylene with ungrafted and / or grafted low modulus polypropylene and optional auxiliaries, melt-extruding and granulating to obtain the anhydride-containing modified polypropylene composite material;

[0126] wherein the preparation method of the grafted low modulus polypropylene comprises the following steps:

[0127] i. placing low modulus polypropylene in a closed reactor and performing inert gas replacement;

[0128] ii. mixing an organic solvent and a free radical initiator, and adding them to the closed reactor;

[0129] iii. removing the organic solvent;

[0130] iv. adding a second grafting monomer, optionally adding an interfacial agent, and optionally swelling the reaction system;

[0131] v. optionally adding a dispersing agent, heating the reaction system to a grafting reaction temperature, and performing a grafting reaction;

[0132] vi. after the reaction is completed, optionally performing filtration, and drying to obtain the modified low modulus polypropylene.

[0133] Specifically, the preparation method comprises the following steps:

[0134] a. placing homopolymerized or copolymerized polypropylene in a closed reactor and performing inert gas replacement;

[0135] b. mixing an organic solvent and a free radical initiator, and adding them to the closed reactor;

[0136] c. removing the organic solvent;

[0137] d. adding a first grafting monomer, adding an interfacial agent in an amount of 0-30 parts, and optionally swelling the reaction system at 20-60°C for 0-24 hours;

[0138] e. adding a dispersing agent in an amount of 0-300 parts, heating the system to a grafting polymerization temperature of 30-130°C, and reacting for 0.5-10 hours;

[0139] f. After the reaction, the modified polypropylene is optionally filtered and dried to obtain the modified polypropylene;

[0140] g. The modified polypropylene is mixed with the ungrafted and / or grafted low modulus polypropylene and optional additives in a proportion, and is mixed and granulated by a twin-screw extruder at a melting temperature of 180-230°C and a screw rotation speed of 30-600 rpm to obtain the anhydride-containing modified polypropylene composite material;

[0141] The preparation method of the grafted low modulus polypropylene comprises the following steps:

[0142] i. The low modulus polypropylene is placed in a closed reactor and subjected to inert gas replacement;

[0143] ii. The organic solvent and the free radical initiator are mixed and added to the closed reactor;

[0144] iii. The organic solvent is removed;

[0145] iv. The second grafting monomer is added, and an interfacial agent is optionally added, and the reaction system is optionally allowed to swell;

[0146] v. A dispersing agent is optionally added, the reaction system is heated to a grafting reaction temperature, and the grafting reaction is carried out;

[0147] vi. After the reaction, the modified low modulus polypropylene is obtained after optional filtration (in the case of using an aqueous dispersing agent) and drying.

[0148] According to the method of the present application, if there is a volatile component in the system after the reaction, the method of the present application preferably comprises a step of devolatilization, which can be carried out by any conventional method, including vacuum extraction at the end of the grafting process or using a stripping agent. Suitable stripping agents include but are not limited to inert gases.

[0149] As described above, the "modified polypropylene" or "modified low modulus polypropylene" of the present application includes not only the product (crude product) directly prepared by grafting reaction of polypropylene / low modulus polypropylene with anhydride monomers and / or alkenyl-containing functional monomers, but also the grafted modified polypropylene purified product obtained by further purification of the product, and therefore, the preparation method of the present application can optionally comprise a step of purifying the crude product. The purification can be carried out by various methods conventional in the art, such as extraction.

[0150] The grafting efficiency of the grafting reaction is not particularly limited in the present application, but a higher grafting efficiency is more advantageous for obtaining the desired anhydride group-containing and alkenyl group-containing functional group graft-modified polypropylene material by one-step grafting reaction. Therefore, it is preferred that the grafting efficiency of the grafting reaction is controlled to be 20 to 100%, and more preferably 25 to 80%. The concept of the grafting efficiency is well known to those skilled in the art, and refers to the amount of the anhydride group-containing and alkenyl group-containing functional group grafted / the total amount of the alkenyl group-containing functional monomer in the reaction feed.

[0151] The inert gas of the present application can be any of various inert gases commonly used in the art, including but not limited to nitrogen, argon.

[0152] In the process of the present application, the graft-modified polypropylene can be mixed with the low modulus polypropylene and optional additives by mechanical mixing, preferably by twin-screw mechanical blending. The additives are, for example, any one or more of antioxidants, stabilizers, processing aids. The types and amounts of the additives are conventional and known to those skilled in the art.

[0153] The anhydride-containing modified polypropylene composite material of the present application described above can be applied in the field of cables, for example, as an insulating material.

[0154] The present application will be further described below in conjunction with examples, but the scope of the present application is not limited to these examples.

[0155] Test methods

[0156] 1. Determination of comonomer content in polypropylene:

[0157] The comonomer content was determined by quantitative Fourier transform infrared (FTIR) spectroscopy. The correlation of the determined comonomer content was calibrated by quantitative nuclear magnetic resonance (NMR) spectroscopy. The quantitative 13 The calibration method of the results obtained by C-NMR spectroscopy was performed according to the conventional method in the art.

[0158] 2. Determination of xylene solubles content (XS)

[0159] The test was performed according to the method specified in GB / T 24282-2009.

[0160] 3. Determination of comonomer content in xylene solubles (XSC2) and the ratio of the intrinsic viscosity of the solubles to the copolymerized polypropylene in the low modulus polypropylene:

[0161] The test was performed using the CRYST-EX instrument of Polymer Char Company. Trichlorobenzene solvent was used, and the temperature was raised to 150°C for dissolution, and kept constant for 90 minutes, and then sampled for testing, and then the temperature was lowered to 35°C, and kept constant for 70 minutes, and then sampled for testing.

[0162] 4. Determination of the weight average molecular weight (M w ) of the polypropylene:

[0163] Determination by high temperature GPC using a Polymer Laboratory PL-GPC 220 gel permeation chromatograph, the sample was dissolved in 1,2,4-trichlorobenzene at a concentration of 1.0 mg / ml. The test temperature was 150°C and the solution flow rate was 1.0 ml / min. The molecular weight of polystyrene was used as an internal reference to establish a standard curve, and the molecular weight and molecular weight distribution of the sample were calculated according to the elution time.

[0164] 5. Determination of the melt flow rate MFR:

[0165] According to the method specified in GB / T 3682-2018, using a CEAST 7026 melt index tester, the melt flow rate was determined at 230°C under a load of 2.16 kg.

[0166] 6. Determination of the melting temperature Tm:

[0167] The melting process and crystallization process of the material were analyzed using a differential scanning calorimeter. The specific operation was as follows: under the protection of nitrogen, 5-10 mg of sample was measured from 20°C to 200°C using a three-stage temperature measurement method, and the change of heat flow was used to reflect the melting and crystallization process of the material, so as to calculate the melting temperature Tm.

[0168] 7. Determination of grafting efficiency GE, parameters M1, M2:

[0169] 2-4 g of the grafted product or the granules of the composite material after crushing were placed in a Soxhlet extractor, and extracted with an organic solvent (for aromatic olefin monomers, acrylate monomers, acid anhydrides, ethyl acetate was used; for silane monomers, acetone was used) for 24 hours, and the unreacted monomers and their homopolymers were removed to obtain a pure grafted product, which was dried and weighed to calculate the parameters Mn, M1, M2 and grafting efficiency GE.

[0170] The parameter Mn (n = A or B) represents the content of structural units derived from acid anhydride monomers and alkenyl-containing polymerized monomers in the grafting state in component A or component B, the parameter M1 represents the content of structural units derived from acid anhydride monomers and alkenyl-containing polymerized monomers in the grafting state in the composite material, which is calculated from M A and M B . The parameter M2 represents the content of structural units derived from acid anhydride monomers in the grafting state in the composite material. In the present application, the calculation formulas of M1, M2 and Mn are as follows:

[0171]

[0172]

[0173]

[0174]

[0175] In the above formula, w0 is the mass of the PP matrix; w1 is the mass before extraction of the grafted product; w2 is the mass after extraction of the grafted product; w3 is the total mass of the grafted monomer added; and w4 is the mass of the composite after extraction. A is the mass of component A in the composite, m B is the mass of component B in the composite, m 产品 is the mass of the composite, %G MAH is the mass content of maleic anhydride. The mass content of maleic anhydride in the composite was tested and calculated according to the method described in the reference (Zhang Guangping, Solid-phase grafting of maleic anhydride onto polypropylene in a screw reactor, China Plastics, Vol. 16, No. 2, 2002, 69-71). MAH .

[0176] 8. Measurement of volume resistivity of direct current:

[0177] The measurement was performed according to the method specified in GB / T 1410-2006.

[0178] 9. Measurement of breakdown field strength:

[0179] The measurement was performed according to the method specified in GB / T 1408-2006.

[0180] 10. Measurement of tensile strength:

[0181] The measurement was performed according to the method specified in GB / T 1040.2-2006.

[0182] 11. Measurement of flexural modulus:

[0183] The measurement was performed according to the method specified in GB / T 9341-2008.

[0184] 12. Measurement of elongation at break:

[0185] The measurement was performed according to the method specified in GB / T 1040-2006.

[0186] 13. Measurement of dielectric constant:

[0187] The measurement was performed according to the method specified in GB / T 1409-2006.

[0188] 14. Characterization of rubber phase

[0189] 1 to 2 composite samples of 5 to 10 cm in length were taken during twin screw extrusion granulation. The composite samples were brittle fractured after being soaked in liquid nitrogen for 15 minutes. The fracture surface of the samples was soaked in xylene at room temperature for 24 hours, then soaked in clean water for 15 minutes under ultrasonic, and finally the fracture surface was rinsed with alcohol and dried. The sample fracture surface was treated with gold spraying, and then the material was characterized by scanning electron microscopy.

[0190] 15. Characterization of the grafted phase and calculation of D50

[0191] The composite samples were brittle fractured after being soaked in liquid nitrogen for 15 minutes. The fracture surface of the samples was treated with gold spraying, and then the material fracture surface was characterized by scanning electron microscopy to obtain the micro-morphology photos. 200 dispersed phases of each sample were taken and the diameter was measured by analysis software, and D50 was calculated by data processing software. D50 represents the median particle size, i.e. the particle size corresponding to the cumulative particle size distribution percentage of 50% of a sample.

[0192] 16. Characterization of the three-phase structure

[0193] The composite samples were sliced after being cooled to -50°C by liquid nitrogen. The micro-morphology of the composite material was characterized by a Dimension rapid scanning atomic force microscope of Bruker Company, Germany.

[0194] Examples

[0195] The raw materials used in the examples and their properties are described in Table A, Table B and Table C.

[0196] Table A

[0197]

[0198]

[0199] *PP 1 : Homopolymer polypropylene used in Examples 1, 3, 5, Comparative Examples 1, 5.

[0200] *PP 2: Copolymer polypropylene used in Examples 2, 6, Comparative Examples 3, 4.

[0201] *PP 3: Copolymer polypropylene used in Example 4.

[0202] *b-PP 1 : Low modulus polypropylene used in Examples 1, 3, 5, Comparative Examples 3, 4, 5.

[0203] *b-PP 2: Low modulus polypropylene used in Examples 2, 6.

[0204] *b-PP 3: Low modulus polypropylene used in Example 4.

[0205] Table B

[0206]

[0207] Table C

[0208]

[0209]

[0210] Example 1

[0211] PP1 powder 2.0 kg, which was screened to remove fine powder less than 40 mesh, was weighed into a 10 L reactor with mechanical stirring. The reactor was closed and the system was deoxygenated by nitrogen replacement. A mixture of 3.95 g of t-butyl peroxy(2-ethylhexanoate) and 30 g of maleic anhydride and 120 g of styrene was added, and the mixture was stirred for 30 minutes. 2 kg of water was added as a dispersant, and the system was swelled at 50 °C for 2 hours. The temperature was raised to 90 °C, and the reaction was carried out for 4 hours. After the reaction was completed, the system was cooled, and the dispersant water was removed by filtration. The polypropylene-g-styrene / maleic anhydride powder was obtained by vacuum drying at 70 °C for 10 hours. The Mw of the product was 1.2 x 105, and the Mw / Mn was 2.0. The content of the styrene / maleic anhydride grafting phase was 4.9%. A = 4.9%.

[0212] Polypropylene-g-styrene / maleic anhydride powder and b-PP1 were weighed in a mass ratio of 36:64, i.e., 1.2 kg in total, and 3000 ppm of antioxidant 1010 / 168 (mass ratio 1:1) was added. The mixture was stirred in a high-speed mixer and granulated by a twin-screw extruder at partition temperatures of 190-200-210-220-220-220-220-220-210-200 °C and a screw rotation speed of 400 rpm to obtain a composite material C1. The performance parameters of the product were tested, and the results are shown in Table 1.

[0213] Figure 1 The atomic force microscope (AFM) image (Log modulus mode) of the material product in Example 1 is shown in FIG. 1. The white area in the figure represents the styrene / maleic anhydride grafting phase, the black area represents the rubber phase, and the other areas represent the continuous phase.

[0214] Figure 2 The microstructure image of the material product in Example 1 under a 20000-fold electron microscope is shown in FIG. 2, in which the spherical dispersed phase is the styrene / maleic anhydride grafting phase. It can be seen that the particle size of the styrene / maleic anhydride grafting phase is small, and the morphology is regular.

[0215] Example 2

[0216] PP2 powder 2.0 kg, which was screened to remove fine powder less than 40 mesh, was added to a 10 L reactor with mechanical stirring. The reaction system was closed and deoxygenated by nitrogen replacement. A mixture of 1.5 g of dibenzoyl peroxide and 13 g of maleic anhydride and 39 g of styrene was added, and the mixture was stirred for 30 minutes. Swelling was carried out at 40 °C for 2 hours, and the temperature was raised to 100 °C. The reaction was carried out for 3 hours. After the reaction was completed, the temperature was lowered, and vacuum drying was carried out at 70 °C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder having a Mw= 1.4%. A = 1.4%.

[0217] Polypropylene-g-styrene / maleic anhydride powder and b-PP2, 1.2 kg in total, were weighed in a mass ratio of 60:40, and 3000 ppm of antioxidant 1035 was added. The mixture was mixed in a high-speed blender and granulated by a twin-screw extruder at partition temperatures of 190-200-210-220-220-220-220-220-210-200 °C and a screw rotation speed of 450 rpm to obtain composite material C2. The performance parameters of the obtained product were tested, and the results are shown in Table 1. Figure 3 The microstructure of the material product in Example 2 under a 20000-fold electron microscope is shown in Figure 1. The spherical dispersed phase, i.e., the styrene / maleic anhydride grafting phase, can be seen. It can be seen that the particle size of the styrene / maleic anhydride grafting phase is small, and the morphology is regular.

[0218] Example 3

[0219] PP1 powder 2.0 kg, which was screened to remove fine powder less than 40 mesh, was added to a 10 L reactor with mechanical stirring. The reaction system was closed and deoxygenated by nitrogen replacement. A mixture of 3.95 g of tert-butyl peroxy(2-ethylhexanoate) and 30 g of maleic anhydride and 120 g of styrene was added, and the mixture was stirred for 30 minutes. Deionized water 2 L was added, and swelling was carried out at 50 °C for 2 hours. The temperature was raised to 90 °C, and the reaction was carried out for 4 hours. After the reaction was completed, the temperature was lowered, and the deionized water was removed by filtration. Vacuum drying was carried out at 70 °C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder having a Mw= 4.9%. A = 4.9%.

[0220] b-PP1 powder 2.0 kg was added to a 10 L reactor with mechanical stirring. The reaction system was closed and deoxygenated by nitrogen replacement. A mixture of 0.28 g of dibenzoyl peroxide and 64.0 g of styrene was added, and the mixture was stirred for 20 minutes. Deionized water 2 L was added, and the temperature was raised to 90 °C. The reaction was carried out for 5 hours. After the reaction was completed, the temperature was lowered, and vacuum drying was carried out at 70 °C for 10 hours to obtain polypropylene-g-styrene powder having a Mw= 1.1%. B = 1.1%.

[0221] Take 1.2 kg of polypropylene-g-styrene / maleic anhydride powder and polypropylene-g-styrene powder in the mass ratio of 38:62, add 3000 ppm of antioxidant 1010 / 168 (mass ratio 1:1) and mix in a high-speed mixer. Granulate through a twin-screw extruder at partition temperatures of 190-200-210-220-220-220-220-220-210-200 °C and a screw speed of 400 rpm to obtain composite material C3. Test the various performance parameters of the product obtained, and the results are shown in Table 1.

[0222] Figure 4 The microstructure photograph of the material product in Example 3 under a 20000-fold electron microscope is shown, wherein the spherical dispersed phase is the styrene / maleic anhydride grafting phase. It can be seen that the particle size of the styrene / maleic anhydride grafting phase is small and the morphology is regular.

[0223] Example 4

[0224] Take 2.0 kg of PP3 powder with fine powder less than 40 mesh removed by sieving, add to a 10 L reaction kettle with mechanical stirring, seal the reaction system and replace oxygen with nitrogen. Add a mixture of 3.5 g of lauryl peroxide and 30 g of maleic anhydride and 32 g of α-methylstyrene, mix for 30 minutes, add 2 L of dispersant deionized water, heat to 90 °C and react for 6 hours. After the reaction is completed, cool down, vacuum dry at 70 °C for 10 hours to obtain polypropylene-g-α-methylstyrene / maleic anhydride powder with a M A = 0.9%.

[0225] Take 1.2 kg of polypropylene-g-α-methylstyrene / maleic anhydride powder and b-PP3 in the mass ratio of 41:59, add 2000 ppm of antioxidant 1024 and mix in a high-speed mixer. Granulate through a twin-screw extruder at partition temperatures of 200-210-220-230-230-230-230-220-220-210 °C and a screw speed of 400 rpm to obtain composite material C4. Test the various performance parameters of the product obtained, and the results are shown in Table 1.

[0226] Example 5

[0227] Take 2.0 kg of PP1 powder with fine powder less than 40 mesh removed by sieving, add to a 10 L reaction kettle with mechanical stirring, seal the reaction system and replace oxygen with nitrogen. Add a mixture of 1.8 g of dibenzoyl peroxide and 120.5 g of methyl methacrylate, mix for 30 minutes, add 2 L of dispersant deionized water, heat to 90 °C and react for 2.5 hours. After the reaction is completed, cool down, vacuum dry at 70 °C for 10 hours to obtain polypropylene-g-methyl methacrylate powder with a M A = 4.6%.

[0228] Take b-PP1 powder 2.0 kg, add to the 10 L reactor with mechanical stirring, close the reaction system, replace oxygen with nitrogen. Add 0.29 g of dibenzoyl peroxide and a mixture of 14.3 g of maleic anhydride and 85.7 g of styrene, stir for 20 minutes, heat to 90°C, and react for 5 hours. After the reaction is completed, cool down, vacuum dry at 70°C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder, its M B = 2.6%.

[0229] According to the mass ratio of 38:62, take 1.2 kg of polypropylene-g-methyl methacrylate powder and polypropylene-g-styrene / maleic anhydride powder, add 3000 ppm of antioxidant 1010 / 168 (mass ratio 1:1), mix in a high-speed mixer. And through the twin-screw extruder, granulate at partition temperature 190-200-210-220-220-220-220-220-210-200°C, screw speed 400 rpm, to obtain composite material C5. Test the performance parameters of the product, and the results are shown in Table 1.

[0230] Example 6

[0231] Take PP2 powder 2.0 kg, add to the 10 L reactor with mechanical stirring, close the reaction system, replace oxygen with nitrogen. Add 1.5 g of dibenzoyl peroxide and a mixture of 13 g of maleic anhydride and 39 g of styrene, stir for 30 minutes, swell at 40°C for 2 hours, heat to 100°C, and react for 3 hours. After the reaction is completed, cool down, vacuum dry at 70°C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder, its M A = 1.4%.

[0232] Take b-PP2 powder 2.0 kg, add to the 10 L reactor with mechanical stirring, close the reaction system, replace oxygen with nitrogen. Add 0.6 g of dibenzoyl peroxide and a mixture of 8.4 g of maleic anhydride and 31.5 g of styrene, stir for 20 minutes, add 2 L of deionized water as a dispersant, heat to 90°C, and react for 5 hours. After the reaction is completed, cool down, vacuum dry at 70°C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder 2, its M B = 1.3%.

[0233] Polypropylene-g-styrene / maleic anhydride powder 1, polypropylene-g-styrene / maleic anhydride powder 2 were weighed according to the mass ratio 60:40, 1.2 kg in total, 3000 ppm antioxidant 1035 was added and mixed in a high-speed mixer. The composite material C6 was obtained by granulation through a twin-screw extruder at partition temperature 190-200-210-220-220-220-220-220-210-200 °C, screw speed 450 rpm. The performance parameters of the obtained product were tested, and the results are shown in Table 1.

[0234] Comparative Example 1

[0235] PP1 powder 2.0 kg, from which fine powder less than 40 mesh was removed by sieving, was weighed and added to a 10 L reaction kettle with mechanical stirring. The reaction system was closed and deoxygenated by nitrogen replacement. 1 g of dibenzoyl peroxide and a mixture of 10 g of maleic anhydride and 40 g of styrene were added, stirred and mixed for 30 minutes, swelled at 40 °C for 4 hours, and then the temperature was raised to 95 °C for 4 hours of reaction. After the reaction was completed, the temperature was lowered by nitrogen blowing, and polypropylene-g-styrene / maleic anhydride powder was obtained.

[0236] Polypropylene-g-styrene / maleic anhydride powder 1.2 kg was weighed, 3000 ppm antioxidant 1010 / 168 (mass ratio 1:1) was added, and mixed in a high-speed mixer. Product D1 was obtained by granulation through a twin-screw extruder at partition temperature 190-200-210-220-220-220-220-220-210-200 °C, screw speed 400 rpm. The performance parameters of the obtained product were tested, and the results are shown in Table 1.

[0237] Comparative Example 2

[0238] Polypropylene powder with the following characteristics was selected: ethylene comonomer content 20.2 mol%, xylene soluble content 44.2 wt%, weight average molecular weight 35.3 x 10 4 g / mol, MFR at 230 °C under a load of 2.16 kg was 1.55 g / 10 min, Tm = 143.6 °C. Polypropylene-g-styrene / maleic anhydride powder 1.2 kg was weighed, 3000 ppm antioxidant 1010 / 168 (mass ratio 1:1) was added, and mixed in a high-speed mixer. Product D2 was obtained by granulation through a twin-screw extruder at partition temperature 190-200-210-220-220-220-220-220-210-200 °C, screw speed 400 rpm. The performance parameters of the obtained product were tested, and the results are shown in Table 1.

[0239] Comparative Example 3

[0240] PP2 powder, b-PP1, 1.2 kg in total, was weighed according to a mass ratio of 50:50, 3000 ppm of antioxidant 1035 was added, and the mixture was stirred in a high-speed blender. The composite material D3 was granulated by a twin-screw extruder at a partition temperature of 190-200-210-220-220-220-220-220-210-200 °C and a screw speed of 450 rpm. The performance parameters of the obtained product were tested, and the results are shown in Table 1.

[0241] Figure 5 The microstructure photo of the product in Comparative Example 3 under an electron microscope at 20000 times. Figure 6 The microstructure photo of the product in Comparative Example 3 after etching under an electron microscope at 20000 times, the black part is the rubber phase. Figure 5 and Figure 6 It can be seen that the product without grafting includes the rubber phase but does not contain the grafting phase. The product after grafting in the application is a three-phase structure including the rubber phase and the grafting phase.

[0242] Comparative Example 4

[0243] PP2 powder, 2.0 kg, screened to remove fine powder less than 40 mesh, was weighed and added to a 10 L reaction kettle with mechanical stirring. The reaction system was closed and deoxygenated by nitrogen replacement. 10 g of dibenzoyl peroxide and a mixture of 100 g of maleic anhydride and 400 g of styrene were added, and the mixture was stirred for 30 minutes. 2 L of deionized water was added, and the system was swelled at 40 °C for 2 hours. The temperature was increased to 90 °C, and the reaction was carried out for 6 hours. After the reaction was completed, the system was cooled, and vacuum drying was carried out at 70 °C for 10 hours to obtain polypropylene-g-styrene / maleic anhydride powder, which had a M A = 13.4%.

[0244] Polypropylene-g-styrene / maleic anhydride powder, b-PP1, 1.2 kg in total, was weighed according to a mass ratio of 50:50, 3000 ppm of antioxidant 1035 was added, and the mixture was stirred in a high-speed blender. The composite material D4 was granulated by a twin-screw extruder at a partition temperature of 190-200-210-220-220-220-220-220-210-200 °C and a screw speed of 450 rpm. The performance parameters of the obtained product were tested, and the results are shown in Table 1. Figure 7 The microstructure photo of the product in Comparative Example 4 under an electron microscope at 20000 times.

[0245] Comparative Example 5

[0246] 1.2 kg of PP1, b-PP1, and styrene / maleic anhydride polymer were weighed according to a mass ratio of 31:64:5. 3000 ppm of antioxidant 1010 / 168 (mass ratio 1:1) was added and mixed thoroughly in a high-speed mixer. The mixture was then granulated using a twin-screw extruder at zone temperatures of 190-200-210-220-220-220-220-210-200℃ and a screw speed of 400 rpm to obtain composite material D5. The performance parameters of the obtained product were tested, and the results are shown in Table 1.

[0247] Figure 8 The image shows the microstructure of the product in Comparative Example 5 under a 20,000x electron microscope. Due to poor compatibility, the dispersed phase size is uneven, with obvious large-sized dispersed phases.

[0248]

[0249] Comparing the data of Example 1 and Comparative Example 1, it can be seen that using T30S powder as the base powder, the resulting polypropylene-g-styrene / maleic anhydride material product has an excessively high flexural modulus and poor mechanical properties, which cannot meet the processing and use requirements of insulating materials.

[0250] Comparing the data of Example 1 and Comparative Example 2, it can be seen that the mechanical properties of the product obtained by the present invention are no less than those of polypropylene prepared by the direct alloying method in the autoclave, while the electrical properties are superior.

[0251] Comparing the data of Example 1 and Comparative Example 3, it can be seen that the mechanical properties of the anhydride-modified polypropylene composite material are almost the same as those of the material without grafted phase, while the breakdown field strength and DC volume resistivity are improved, indicating that the anhydride-modified polypropylene composite material of the present invention has good electrical properties.

[0252] Comparing the data of Example 1 and Comparative Example 4, it can be seen that if the amount of grafted monomer added is too high (M1 value is too high) and the D50 of the grafted phase is too large, the breakdown field strength of the resulting anhydride-modified polypropylene composite material will decrease significantly and cannot meet the actual application requirements.

[0253] Comparing the data of Example 1 and Comparative Example 5, it can be seen that using the method of blending anhydride / alkenyl functional monomer copolymer results in an excessively large dispersed phase size and uneven dispersion, which leads to a significant decrease in the breakdown field strength and volume resistivity of the material, greatly affecting the electrical properties of the material.

[0254] In summary, as can be seen from the data in Table 1, the anhydride-modified polypropylene composite material obtained by this invention not only has excellent electrical insulation properties, but also good mechanical properties.

[0255] Furthermore, the dielectric constant data shows that the material of this invention meets the necessary conditions for insulation.

[0256] Embodiments of the application have been described above, with the understanding that these embodiments are exemplary only and are not exhaustive of all embodiments of the application. Many modifications and variations of the described embodiments are possible in light of the above teachings. The endpoints of the ranges and any values described are not limited to the precise values stated. The endpoints of the ranges and any values should be construed as being approximate. The exact number of values recited will depend on the context. For a range such as 2 to 5, any number between (and including) 2 and 5, e.g., 2, 3, 4, 5, 2.1, 2.9, 3.1, 3.9, 4.1, 4.9, 5.1, 5.9 etc. should be considered to be within the range of values unless otherwise indicated within the context of the description.

Claims

1. An anhydride-containing modified polypropylene composite comprising a propylene-based continuous phase, a rubber phase dispersed in the propylene-based continuous phase, and a grafted phase derived from an anhydride monomer and an alkenyl-containing functional monomer; wherein, The D50 of the grafted phase is less than 170 nm; Based on the total weight of the anhydride-modified polypropylene composite material, the xylene-soluble content of the anhydride-modified polypropylene composite material is 10-55 wt%; the content of grafted structural units in the anhydride-modified polypropylene composite material is 0.3-5 wt%, of which the content of grafted structural units derived from anhydride monomers is 0.05-2 wt%; the anhydride-modified polypropylene composite material has a flexural modulus of 200-1000 MPa. The anhydride-modified polypropylene composite material comprises modified polypropylene (A) and low-modulus polypropylene (B), wherein the modified polypropylene (A) provides at least a propylene-based continuous phase and a grafted phase, and the low-modulus polypropylene (B) provides a propylene-based continuous phase and a rubber phase, and optionally provides a grafted phase. The low-modulus polypropylene (B) is an ethylene-propylene copolymer with a flexural modulus of less than 300 MPa and has the following characteristics: comonomer content of 8-25 wt%; xylene-soluble content of 18-75 wt%; melt flow rate of 0.1-15 g / 10 min at 230 °C and 2.16 kg load; melt temperature Tm of 120-165 °C; comonomer content of xylene-soluble content of 10-50 wt%; and intrinsic viscosity ratio of xylene-soluble content to low-modulus polypropylene of 0.5-3.

2. The anhydride-containing modified polypropylene composite of claim 1, wherein, The xylene-soluble content of the anhydride-modified polypropylene composite material is 15-45 wt% based on the total weight of the anhydride-modified polypropylene composite material.

3. The anhydride-containing modified polypropylene composite of claim 2, wherein, The xylene-soluble content of the anhydride-modified polypropylene composite material is 20-40 wt% based on the total weight of the anhydride-modified polypropylene composite material.

4. The anhydride-containing modified polypropylene composite of claim 1, wherein, The content of the grafted structural units in the anhydride-modified polypropylene composite material is 0.7~3 wt%, of which the content of the grafted structural units derived from the anhydride monomer is 0.2~0.5 wt%.

5. The anhydride-containing modified polypropylene composite of claim 1, wherein, The comonomer content of the low-modulus polypropylene is 10~22 wt%.

6. The anhydride-containing modified polypropylene composite of claim 1, wherein, The xylene-soluble content of the low-modulus polypropylene is 30-70 wt%.

7. The anhydride-containing modified polypropylene composite of claim 6, wherein, The xylene-soluble content of the low-modulus polypropylene is 30~67 wt%.

8. The anhydride-containing modified polypropylene composite of claim 1, wherein, The low-modulus polypropylene has a melt flow rate of 0.2~7 g / 10min at 230℃ and 2.16 kg load.

9. The anhydride-containing modified polypropylene composite of claim 1, wherein, The melting temperature Tm of the low-modulus polypropylene is 125~150 ℃.

10. The anhydride-containing modified polypropylene composite of claim 1, wherein, The flexural modulus of the low-modulus polypropylene is 10~250 MPa.

11. The anhydride-containing modified polypropylene composite of claim 10, wherein, The flexural modulus of the low-modulus polypropylene is 15~250 MPa.

12. The anhydride-containing modified polypropylene composite of claim 1, wherein, The xylene-soluble copolymer content of the low-modulus polypropylene is 20-35 wt%.

13. The anhydride-containing modified polypropylene composite of claim 1, wherein, The ratio of xylene-soluble component to intrinsic viscosity of the low-modulus polypropylene is 0.8 to 1.

3.

14. The anhydride-containing modified polypropylene composite of claim 1, wherein, The grafted phase has a D50 of 10~150 nm; the anhydride-modified polypropylene composite material has a flexural modulus of 200~700 MPa.

15. The anhydride-containing modified polypropylene composite of claim 14, wherein, The D50 of the grafted phase is 55~110 nm.

16. The anhydride-containing modified polypropylene composite of claim 14, wherein, The anhydride-modified polypropylene composite material has a flexural modulus of 250-600 MPa.

17. The anhydride-containing modified polypropylene composite of claim 1, wherein, The anhydride-modified polypropylene composite material has at least one of the following characteristics: a melt flow rate of 0.5~15 g / 10 min at 230 °C and 2.16 kg load; an elongation at break ≥200%; and a tensile strength greater than 5 MPa.

18. The anhydride-containing modified polypropylene composite of claim 17, wherein, The anhydride-modified polypropylene composite material has a melt flow rate of 1~10 g / 10min at 230 °C and 2.16 kg load.

19. The anhydride-containing modified polypropylene composite of claim 18, wherein, The anhydride-modified polypropylene composite material has a melt flow rate of 1.2~6 g / 10min at 230 °C and 2.16 kg load.

20. The anhydride-containing modified polypropylene composite of claim 17, wherein, The elongation at break of the anhydride-modified polypropylene composite material is ≥300%.

21. The anhydride-containing modified polypropylene composite of claim 17, wherein, The tensile strength of the anhydride-modified polypropylene composite material is 10~25 MPa.

22. The anhydride-containing modified polypropylene composite of claim 1, wherein, The anhydride-modified polypropylene composite material has at least one of the following characteristics: - The maximum operating temperature of the anhydride-modified polypropylene composite material is ≥90℃; - The breakdown field strength Eg of the anhydride-modified polypropylene composite material at 110 °C is ≥285 kV / mm; - the direct volume resistivity p of the anhydride-containing modified polypropylene composite at 110 °C at a field strength of 40 kV / mm vg ≥ 2.0 x 10 13 Ω m; - The dielectric constant of the anhydride-modified polypropylene composite material is greater than 2.0 at 110 °C and 50 Hz.

23. The anhydride-containing modified polypropylene composite of claim 22, wherein, The maximum operating temperature of the anhydride-modified polypropylene composite material is 100~160 ℃.

24. The anhydride-containing modified polypropylene composite of claim 23, wherein, The maximum operating temperature of the anhydride-modified polypropylene composite material is 110~140 ℃.

25. The anhydride-containing modified polypropylene composite of claim 22, wherein, The breakdown field strength Eg of the anhydride-modified polypropylene composite material at 110 °C is 290~800 kV / mm.

26. The anhydride-containing modified polypropylene composite of claim 25, wherein, The breakdown field strength Eg of the anhydride-modified polypropylene composite material at 110 °C is 300~750 kV / mm.

27. The anhydride-modified polypropylene composite material according to claim 22, wherein, The anhydride-containing modified polypropylene composite has a direct current volume resistivity p at 110 °C, 40 kV / mm field strength of 1.0 x 1010 vg is 4.0 x 1010 13 ohm m 20 ohm m.

28. The anhydride-containing modified polypropylene composite of claim 22, wherein, The dielectric constant of the anhydride-modified polypropylene composite material is 2.1~2.5 at 110 °C and 50 Hz.

29. The anhydride-containing modified polypropylene composite of claim 1, wherein, The anhydride monomer is selected from anhydrides having at least one degree of olefin unsaturation.

30. The anhydride-containing modified polypropylene composite of claim 29, wherein, The anhydride monomer is selected from maleic anhydride and / or itaconic anhydride.

31. The anhydride-containing modified polypropylene composite of claim 30, wherein, The anhydride monomer is maleic anhydride.

32. The anhydride-containing modified polypropylene composite of claim 1, wherein, The olefin-containing polymeric monomer is selected from at least one monomer having the structure shown in Formula 1. Formula 1 In Formula 1, R b , R c , R d are each independently selected from H, substituted or unsubstituted alkyl; R a is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted ester, substituted or unsubstituted carboxyl, substituted or unsubstituted cycloalkyl or heterocyclyl, cyano.

33. The anhydride-containing modified polypropylene composite of claim 32, wherein, R b , R c , R d are each independently selected from H, substituted or unsubstituted C1-C6alkyl; R a is selected from substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted C1-C 20 alkoxy, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C1-C 20 ester, substituted or unsubstituted C1-C 20 carboxyl, substituted or unsubstituted C3-C 20 cycloalkyl or heterocyclyl, cyano, said substituted groups being halogen, hydroxyl, amino, C1-C6alkyl, C3-C6cycloalkyl.

34. The anhydride-containing modified polypropylene composite of claim 33, wherein, R b , R c , R d each independently is selected from H, substituted or unsubstituted C1-C3alkyl.

35. The anhydride-containing modified polypropylene composite of claim 33, wherein, R a selected from substituted or unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 12 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 18 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 12 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 12 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 12 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 12 unsubstituted C1-C6alkyl, substituted or unsubstituted C3-C6cycloalkyl, halogen, cyano, and oxo; 36. The anhydride-containing modified polypropylene composite of claim 35, wherein, R a substituted or unsubstituted C1-C6alkyl, substituted or unsubstituted C1-C6alkoxy, substituted or unsubstituted C6-C8aryl, substituted or unsubstituted C1-C6ester, substituted or unsubstituted C1-C6carboxyl, substituted or unsubstituted C3-C6cycloalkyl or heterocyclyl, cyano. 12 substituted or unsubstituted C1-C6alkyl, substituted or unsubstituted C1-C6alkoxy, substituted or unsubstituted C6-C8aryl, substituted or unsubstituted C1-C6ester, substituted or unsubstituted C1-C6carboxyl, substituted or unsubstituted C3-C6cycloalkyl or heterocyclyl, cyano.

37. The anhydride-containing modified polypropylene composite of claim 33, wherein, The heterocyclic group is selected from imidazole, pyrazol, carbazole, pyrrolidone, pyridinyl, piperidinyl, caprolactam, pyrazinyl, thiazolyl, purine, morpholino, and oxazolino.

38. The anhydride-containing modified polypropylene composite of claim 33, wherein, R b , R c , R d each independently is selected from H, substituted or unsubstituted C1-C6alkyl; R a a combination of a group selected from a group of Formula 2, a group of Formula 3, a group of Formula 4, a group of Formula 6, a group of Formula 6, and a group of Formula 7, a heterocyclic group; Formula 2 R in formula 2 is selected from H, halogen, hydroxyl, amino, phosphato, sulfato, substituted or unsubstituted C1-C 4 -R 8 each independently selected from H, halogen, hydroxyl, amino, phosphato, sulfato, substituted or unsubstituted C1-C 12 alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester, substituted or unsubstituted C1-C 12 amine, said substituted groups being selected from halogen, hydroxyl, amino, phosphato, sulfato, C1-C 12 alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy, C1-C 12 ester, C1-C 12 amine; Formula 3 In Equation 3, R4-R 10 Each is independently selected from H, halogen, hydroxyl, amino, phosphate group, sulfonic acid group, substituted or unsubstituted C1-C. 12 Alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester group, substituted or unsubstituted C1-C 12 The substituted amino group, wherein the substituted group is selected from halogen, hydroxyl, amino, phosphate, sulfonic acid, C1-C 12 Alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy groups, C1-C 12 ester group, C1-C 12 The amino group; Formula 4 In formula 4, R4'-R 10 each independently selected from H, halogen, hydroxyl, amino, phosphato, sulfato, substituted or unsubstituted C1-C 12 alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C1-C 12 alkoxy, substituted or unsubstituted C1-C 12 ester, substituted or unsubstituted C1-C 12 amine, the substituted groups being selected from halogen, hydroxyl, amino, phosphato, sulfato, C1-C 12 alkyl, C3-C 12 cycloalkyl, C1-C 12 alkoxy, C1-C 12 ester, C1-C 12 amine; Formula 6 Formula 7 In Formula 6, R m selected from substituted or unsubstituted linear alkyl, C3-C 20 linear alkyl, C3-C 20 branched alkyl, C3-C 12 cycloalkyl, C3-C 12 epoxyalkyl, C3-C 12 epoxyalkylalkyl, the substituted groups being selected from at least one of halogen, amino, and hydroxyl.

39. The anhydride-containing modified polypropylene composite of claim 38, wherein, In formula 2, R 4 -R 8 each independently is selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy.

40. The anhydride-containing modified polypropylene composite of claim 38, wherein, In formula 3, R4-R 10 each independently selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6alkyl, substituted or unsubstituted C1-C6alkoxy, the substituted groups being selected from halogen, hydroxyl, amino, C1-C6alkyl, C1-C6alkoxy.

41. The anhydride-containing modified polypropylene composite of claim 38, wherein, In formula 4, R4’-R 10 each independently selected from H, halogen, hydroxyl, amino, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, the substituted groups being selected from halogen, hydroxyl, amino, C1-C6 alkyl, C1-C6 alkoxy.

42. The anhydride-containing modified polypropylene composite of claim 38, wherein, The alkenyl-containing functional monomer is an aromatic olefin monomer, wherein the aromatic olefin monomer is selected from at least one of styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, monosubstituted or polysubstituted styrene, monosubstituted or polysubstituted 1-vinylnaphthalene, and monosubstituted or polysubstituted 2-vinylnaphthalene; and / or, The alkenyl-containing functional monomer is an alkenyl-containing silane monomer, wherein the alkenyl-containing silane monomer is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltriisopropoxysilane, vinyltritert-butoxysilane, vinyltriacetoxysilane, methylvinyldimethoxysilane, ethylvinyldiethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, allyltriisopropoxysilane, vinyltris(β-methoxyethoxy)silane, allyltris(β-methoxyethoxy)silane, allyltritert-butoxysilane, allyltriacetoxysilane, methylallyldimethoxysilane, and ethylallyldiethoxysilane; and / or, The alkenyl-containing functional monomer is an acrylate monomer or an optional acrylic monomer.

43. The anhydride-containing modified polypropylene composite of claim 42, wherein, The substituted group is selected from at least one of halogen, hydroxyl, amino, phosphate, sulfonic acid, C1-C8 straight-chain alkyl, C3-C8 branched alkyl or cycloalkyl, C1-C6 straight-chain alkoxy, C3-C8 branched alkoxy or cycloalkoxy, C1-C8 straight-chain ester, C3-C8 branched ester or cycloester, C1-C8 straight-chain amino, and C3-C8 branched amino or cycloamino.

44. The anhydride-containing modified polypropylene composite of claim 42, wherein, The aromatic olefin monomer is selected from at least one of styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, and 4-methylstyrene.

45. The anhydride-containing modified polypropylene composite of claim 42, wherein, The acrylate monomers are selected from at least one of methyl methacrylate, sec-butyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, coconut oleate methacrylate, octadecyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, and glycidyl methacrylate.

46. The anhydride-containing modified polypropylene composite of claim 45, wherein, The acrylic monomer is selected from at least one of acrylic acid, methacrylic acid and 2-ethylacrylic acid.

47. The anhydride-containing modified polypropylene composite of claim 42, wherein, The molar ratio of structural units derived from acrylate monomers to structural units derived from acrylic monomers is 1:0~2.

48. The anhydride-containing modified polypropylene composite of claim 47, wherein, The molar ratio of structural units derived from acrylate monomers to structural units derived from acrylic monomers is 1:0.125~1.

49. The anhydride-containing modified polypropylene composite of claim 42, wherein, The alkenyl-containing polymeric monomer is selected from at least one of vinyl acetate, styrene, α-methylstyrene, (meth)acrylate, vinyl alkyl ether, vinylpyrrolidone, vinylpyridine, vinylimidazolium, and acrylonitrile.

50. The anhydride-containing modified polypropylene composite of claim 49, wherein, The (meth)acrylate is at least one of methyl (meth)acrylate, ethyl (meth)acrylate, and glycidyl (meth)acrylate.

51. The anhydride-containing modified polypropylene composite of claim 49, wherein, The alkenyl-containing polymeric monomer is selected from vinyl acetate, styrene, and α-methylstyrene.

52. The anhydride-containing modified polypropylene composite of claim 51, wherein, The alkenyl-containing polymeric monomer is styrene.

53. The anhydride-modified polypropylene composite of any of claims 1-52, wherein, The modified polypropylene (A) is polypropylene (A) grafted with alkenyl functional monomers and optionally with anhydride monomers, and the low-modulus polypropylene (B) is unmodified low-modulus polypropylene, and / or low-modulus polypropylene grafted with alkenyl functional monomers and optionally with anhydride monomers; when the modified polypropylene (A) is polypropylene grafted with alkenyl functional monomers, the low-modulus polypropylene (B) must be low-modulus polypropylene grafted with both alkenyl functional monomers and anhydride monomers.

54. The anhydride-containing modified polypropylene composite of claim 53, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the content of polypropylene (A) is 20-80 wt%, and the content of low-modulus polypropylene (B) is 20-80 wt%.

55. The anhydride-containing modified polypropylene composite of claim 54, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the content of polypropylene (A) is 30-70 wt%, and the content of low-modulus polypropylene (B) is 30-70 wt%.

56. The anhydride-containing modified polypropylene composite of claim 55, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the content of polypropylene (A) is 35-65 wt%, and the content of low-modulus polypropylene (B) is 35-65 wt%.

57. The anhydride-containing modified polypropylene composite of claim 53, wherein, The anhydride-modified polypropylene composite material is prepared by blending the modified polypropylene (A) with the low-modulus polypropylene (B).

58. The anhydride-containing modified polypropylene composite of claim 53, wherein, The modified polypropylene (A) comprises structural units derived from homopolymer or copolymer polypropylene, structural units derived from alkenyl functional monomers, and optionally structural units derived from anhydride monomers; the content of grafted structural units in the modified polypropylene (A) is 0.1 to 10 wt% based on the weight of the modified polypropylene (A).

59. The anhydride-containing modified polypropylene composite of claim 58, wherein, Based on the weight of the modified polypropylene (A), the content of grafted structural units in the modified polypropylene (A) is 1 to 5 wt%.

60. The anhydride-containing modified polypropylene composite of claim 58, wherein, The homopolymer or copolymer polypropylene has at least one of the following characteristics: a comonomer content of 0-15 mol%; a melt flow rate at 230 °C under a load of 2.16 kg of 1-10 g / 10 min; a melting temperature Tm of 110-180 °C; a weight average molecular weight of 20x10 4 ~50x10 4 g / mol; a flexural modulus of 500-2000 MPa; an elongation at break of > 200%; a tensile strength of more than 5 MPa.

61. The anhydride-containing modified polypropylene composite of claim 60, wherein, The homopolymer or copolymer polypropylene contains 0-12 mol of comonomer.

62. The anhydride-containing modified polypropylene composite of claim 61, wherein, The homopolymer or copolymer polypropylene contains 0-8 mol of comonomer.

63. The anhydride-containing modified polypropylene composite of claim 60, wherein, The homopolymer or copolymer polypropylene has a melt flow rate of 2~5 g / 10 min at 230 °C and 2.16 kg load.

64. The anhydride-containing modified polypropylene composite of claim 60, wherein, The melting temperature Tm of the homopolymer or copolymer polypropylene is 120~170 ℃.

65. The anhydride-containing modified polypropylene composite of claim 60, wherein, The flexural modulus of the homopolymer or copolymer polypropylene is 600~1700 MPa.

66. The anhydride-containing modified polypropylene composite of claim 60, wherein, The homopolymer or copolymer polypropylene has an elongation at break of ≥300%.

67. The anhydride-containing modified polypropylene composite of claim 60, wherein, The tensile strength of the homopolymer or copolymer polypropylene is 10~40 MPa.

68. The anhydride-containing modified polypropylene composite of claim 58, wherein, The comonomer of the copolymerized polypropylene is selected from at least one of the C2-C8 α-olefins other than propylene; the comonomer content is 0.1~15 mol based on the total molar amount of monomers.

69. The anhydride-containing modified polypropylene composite of claim 68, wherein, The comonomer of the copolymerized polypropylene is selected from at least one of ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene.

70. The anhydride-containing modified polypropylene composite of claim 69, wherein, The comonomer of the copolymerized polypropylene is ethylene and / or 1-butene.

71. The anhydride-containing modified polypropylene composite of claim 68, wherein, The comonomer content is 0.1~12 mol based on the total molar amount of monomers.

72. The anhydride-containing modified polypropylene composite of claim 71, wherein, The comonomer content is 0.1~8 mol based on the total molar amount of monomers.

73. The anhydride-containing modified polypropylene composite of claim 1, wherein, The ethylene-propylene copolymer contains a propylene homopolymer and / or propylene random copolymer matrix component (1) as the matrix phase, and another propylene copolymer component (2) dispersed therein as the dispersed phase.

74. The anhydride-containing modified polypropylene composite of claim 1, wherein, The low-modulus polypropylene has an island structure or a bicontinuous structure.

75. The anhydride-containing modified polypropylene composite of claim 1, wherein, The low-modulus polypropylene is prepared in situ within the reactor.

76. The anhydride-containing modified polypropylene composite of claim 1, wherein, Based on the weight of low modulus polypropylene (B), the content of grafted structural units in the low modulus polypropylene (B) is 0~5 wt%.

77. The anhydride-containing modified polypropylene composite of claim 76, wherein, Based on the weight of low modulus polypropylene (B), the content of grafted structural units in the low modulus polypropylene (B) is 0.5~2.5 wt%.

78. A method of making the anhydride-modified polypropylene composite of any of claims 1-77, comprising the steps of: Modified polypropylene (A) is blended with low-modulus polypropylene (B) to obtain the anhydride-modified polypropylene composite material. The modified polypropylene (A) is polypropylene (A) grafted with alkenyl functional monomers and optionally with anhydride monomers. The low-modulus polypropylene (B) is unmodified low-modulus polypropylene and / or low-modulus polypropylene grafted with alkenyl functional monomers and optionally with anhydride monomers. When the modified polypropylene (A) is polypropylene grafted with alkenyl functional monomers, the low-modulus polypropylene (B) must be low-modulus polypropylene grafted with both alkenyl functional monomers and anhydride monomers.

79. The method of making an anhydride-containing modified polypropylene composite of claim 78, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the amount of polypropylene (A) is 20-80 wt%, and the amount of low-modulus polypropylene (B) is 20-80 wt%.

80. The method of making an anhydride-containing modified polypropylene composite of claim 79, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the amount of polypropylene (A) is 30-70 wt%, and the amount of low-modulus polypropylene (B) is 30-70 wt%.

81. The method of making an anhydride-containing modified polypropylene composite of claim 80, wherein, Based on the total weight of the anhydride-modified polypropylene composite material, the amount of polypropylene (A) is 35-65 wt%, and the amount of low-modulus polypropylene (B) is 35-65 wt%.

82. The method of manufacturing of claim 78, wherein, The preparation method includes the following steps: S1: In the presence of an inert gas, a reaction mixture A, comprising homopolymer or copolymer polypropylene and a first grafting monomer, is subjected to a grafting reaction to obtain modified polypropylene. Optionally, in the presence of an inert gas, a reaction mixture B comprising low-modulus polypropylene and a second grafted monomer is subjected to a grafting reaction to obtain modified low-modulus polypropylene. S2: The modified polypropylene, unmodified low-modulus polypropylene and / or the modified low-modulus polypropylene and optional additives are mixed, extruded and granulated to obtain the anhydride-modified polypropylene composite material. The first graft monomer and the second graft monomer are each independently an alkenyl functional monomer and an optional acid anhydride monomer.

83. The method of manufacturing according to claim 82, wherein, The reaction mixture A and the reaction mixture B each independently comprise a free radical initiator; the free radical initiator is selected from peroxide free radical initiators and / or azo free radical initiators.

84. The method of manufacturing according to claim 83, wherein, The peroxide radical initiator is selected from at least one of benzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, lauroyl peroxide, dodecyl peroxide, tert-butyl peroxide, diisopropyl peroxide, tert-butyl peroxide, and dicyclohexyl peroxide; the azo radical initiator is azobisisobutyronitrile and / or azobisisoheptanenitrile.

85. The method of manufacturing according to claim 83, wherein, The ratio of the mass of the free radical initiator to the total mass of the grafted monomers in the reaction system is 0.1~10:

100.

86. The method of manufacturing according to claim 85, wherein, The ratio of the mass of the free radical initiator to the total mass of the grafted monomers in the reaction system is 0.5~6:

100.

87. The method of manufacturing of claim 82, wherein, The total mass ratio of the first grafted monomer to the homopolymer or copolymer polypropylene is 0.5~35:100; The total mass ratio of the second grafted monomer to the low-modulus polypropylene is 0.5~15:100; When the grafted monomers include alkenyl functional monomers and anhydride monomers, the mass ratio of alkenyl functional monomers to anhydride monomers is 0.5~10:

1.

88. The method of manufacturing according to claim 87, wherein, The total mass ratio of the first grafted monomer to the mass ratio of the homopolymer or copolymer polypropylene is 2~30:

100.

89. The method of manufacturing according to claim 88, wherein, The total mass ratio of the first grafted monomer to the homopolymer or copolymer polypropylene is 2.5~20:

100.

90. The method of manufacturing of claim 87, wherein, The total mass ratio of the second grafted monomer to the low-modulus polypropylene is 2~10:

100.

91. The method of manufacturing according to claim 87, wherein, When the grafted monomers include alkenyl functional monomers and anhydride monomers, the mass ratio of alkenyl functional monomers to anhydride monomers is 2~8:

1.

92. The method of manufacturing of claim 82, wherein, The grafting reaction is carried out at a temperature of 30~130 ℃ for 0.5~10 hours.

93. The method of manufacturing according to claim 92, wherein, The grafting reaction is carried out at a temperature of 60-120 °C for 1-6 hours.

94. The method of manufacturing of claim 83, wherein, The reaction mixture A and the reaction mixture B each independently further include at least one of the following components: a dispersant, an interface agent, and an organic solvent, wherein the mass content of the dispersant is 50-300% of the mass of homopolymer or copolymer polypropylene / low modulus polypropylene, the mass content of the interface agent is 1-30% of the mass of homopolymer or copolymer polypropylene / low modulus polypropylene, and the mass content of the organic solvent is 1-35% of the mass of homopolymer or copolymer polypropylene / low modulus polypropylene.

95. The method of manufacturing according to claim 94, wherein, The preparation method includes the following steps: a. Place homopolymer or copolymer polypropylene in a closed reactor and replace it with an inert gas; b. Add the free radical initiator and the first grafted monomer to the closed reactor and stir to mix; c. Optionally add an interfacial agent and optionally swell the reaction system; d. Optionally add a dispersant to raise the temperature of the reaction system to the grafting reaction temperature and carry out the grafting reaction; e. After the reaction is complete, the mixture is optionally filtered and dried to obtain modified polypropylene; f. The modified polypropylene is mixed with ungrafted and / or grafted low-modulus polypropylene and optional additives, and then melt-extruded and granulated to obtain the anhydride-modified polypropylene composite material. The method for preparing the grafted low-modulus polypropylene includes the following steps: i. Place the low-modulus polypropylene in a closed reactor and replace it with an inert gas; ii. Add the free radical initiator and the second grafted monomer into the closed reactor and stir to mix; iii. Optionally add an interfacial agent and optionally swell the reaction system; iv. Optionally, add a dispersant to raise the temperature of the reaction system to the grafting reaction temperature and carry out the grafting reaction; v. After the reaction is complete, the mixture is optionally filtered and dried to obtain modified low-modulus polypropylene.

96. The method of manufacturing according to claim 94, wherein, The preparation method includes the following steps: a. Place homopolymer or copolymer polypropylene in a closed reactor and replace it with an inert gas; b. Mix the organic solvent and the free radical initiator, and add them to the closed reactor; c. Remove the organic solvent; d. Add the first graft monomer, optionally add an interfacial agent, and optionally allow the reaction system to swell; e. Optionally add a dispersant, heat the reaction system to the grafting reaction temperature, and carry out the grafting reaction; f. After the reaction is complete, the mixture is optionally filtered and dried to obtain modified polypropylene; g. The modified polypropylene is weighed and mixed with ungrafted and / or grafted low-modulus polypropylene and optional additives in proportion, and then melt-extruded and granulated to obtain the anhydride-modified polypropylene composite material. The method for preparing the grafted low-modulus polypropylene includes the following steps: i. Place the low-modulus polypropylene in a closed reactor and replace it with an inert gas; ii. Mix the organic solvent and the free radical initiator and add them to the closed reactor; iii. Remove the organic solvent; iv. Add a second graft monomer, optionally add an interfacial agent, and optionally swell the reaction system; v. Optionally add a dispersant, raise the temperature of the reaction system to the grafting reaction temperature, and carry out the grafting reaction; vi. After the reaction is complete, the mixture is optionally filtered and dried to obtain modified low-modulus polypropylene.

97. The application of the anhydride-modified polypropylene composite material according to any one of claims 1-77.

98. The use of claim 97, wherein, The anhydride-modified polypropylene composite material is used in the cable industry.

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