Ethylene polymer composition as well as preparation method and application thereof

Abstract

The invention discloses an ethylene polymer composition and a preparation method and application thereof.The ethylene polymer composition is prepared from an ethylene polymer and a composite organic improving agent, the composite organic improving agent is composed of a compound A and a compound B. The compound A is one or more of monooxadiamide derivatives, and the compound B is one or more of monooxadiamide derivatives. The compound B is one or more of bis-oxadiamide derivatives, and the ethylene polymer composition has a crystal form of a variant spherocrystal. The preparation method comprises the following steps: uniformly mixing the ethylene polymer and the composite organic improver, carrying out melt blending on the obtained mixed material, and cooling according to a cooling rate to obtain the ethylene polymer composition. The ethylene polymer composition has the advantages of low turbidity, low cost, fast crystallization, high light transmittance, high mechanical properties and the like, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and relates to an ethylene polymer composition, a preparation method and an application thereof, and in particular to an ethylene polymer composition containing a composite organic improver, a preparation method and an application thereof. Background Art

[0002] Among polymer materials, ethylene polymers are the most consumed and widely used general-purpose thermoplastic resins in the world today. Due to their popularity and expectations in numerous fields, the market has placed high demands on ethylene polymers for high strength, high modulus, high transparency, and high speed. Additives are a common method for improving the crystallization and macroscopic properties of semi-crystalline polymers. Additives primarily include organic and inorganic additives. However, to date, additives for ethylene polymers (particularly commercial additive products) are rare. Therefore, it is necessary to develop a novel, highly effective additive to improve the crystallization, optical (particularly turbidity), and mechanical properties of ethylene polymers to broaden their application areas.

[0003] Spherulites are the most common crystalline form of polymers, including ethylene polymers. Spherulites of polymers appear as a characteristic black cross extinction image between crossed polarizers in a polarizing microscope. The properties of semicrystalline polymers, including optical and physical and mechanical properties, depend on the polymer's crystal structure, such as the spherulite structure. A process called nucleation must occur during the initial stages of spherulite growth, after which the lamellae undergo chain folding or self-organization around the nucleus. In homogeneous nucleation, nucleation occurs at defects or inconsistencies within the polymer chain. In heterogeneous nucleation, nucleation occurs at the surface of an external phase. This external phase is known as an additive, nucleation promoter, or organic modifier. Generally, in polymers with heterogeneous nucleation, crystallization occurs earlier and more rapidly during cooling, resulting in shorter cooling times, increased nucleation density, and smaller spherulite size.

[0004] The types and quantities of existing organic improvers for ethylene polymers are relatively small. This is mainly because the molecular chain structure of ethylene polymers is regular and its crystallization rate is the fastest among all polymers. Therefore, organic improvers for ethylene polymers need to have higher nucleation efficiency and nucleation ability. Based on this, the research and development basis of organic improvers for ethylene polymers is the most demanding among all polymers. So far, there are very few commercial products called organic improvers for ethylene polymers. Among them, there are almost no products of organic improvers for ethylene polymers that have the functions of promoting crystallization, reducing turbidity, and increasing mechanical properties. HPN-20E is one of the few commercial ethylene polymer additive products. It is mainly used to improve the airtightness of products and hardly reduces turbidity. The research hotspots and applications of anti-reflection additives are mainly concentrated on polypropylene, such as the commercial additive Millad 3988. However, its effect on improving the turbidity of ethylene polymers is not good and has not been used in practice.

[0005] Turbidity is a commonly used measure of the clarity of polymer products, expressed as a percentage, with or without additives. Generally, even a one-percentage-point reduction in turbidity is of significant industrial significance. Given the demanding R&D requirements for ethylene polymers, even a one-percentage-point or even a fractional-point reduction in turbidity is invaluable in the ethylene polymer field. It's important to note that not all compounds can reduce turbidity. Of the 118 million compounds currently available, fewer than 10 are known to reduce polymer turbidity. A further limitation is that even inappropriate additive dosage can result in turbidity remaining unchanged or even increasing. Therefore, the plastics additive industry is constantly searching for additives that can provide lower turbidity at lower dosage levels. However, low turbidity isn't the only factor in determining the suitability of a plastics additive. Poor thermal stability can lead to undesirable yellowing and precipitation at high processing temperatures, necessitating additives with excellent thermal stability. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an ethylene polymer composition having low turbidity, low cost, fast crystallization, high light transmittance and high mechanical properties, as well as a preparation method and application thereof.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0008] An ethylene polymer composition is prepared using an ethylene polymer and a composite organic improver as raw materials, wherein the composite organic improver is composed of compound A and compound B, wherein compound A is one or more monooxalyl diamide derivatives, and compound B is one or more bisoxalyl diamide derivatives; the ethylene polymer composition has a crystalline morphology of modified spherulites, wherein the modified spherulites include a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area.

[0009] The structural formula of the monooxalyl diamide derivative is shown in formula (I):

[0010]

[0011] The structural formula of the bisoxalyl diamide derivative is shown in formula (II):

[0012]

[0013] Wherein, R1, R2, R3, R4 and R5 are independently selected from one of hydrocarbon groups having 1 to 40 carbon atoms.

[0014] In the above-mentioned ethylene polymer composition, preferably, the variant spherulites have one or more of the following characteristics:

[0015] (1) The overall morphology of the variant spherulites is spherical or quasi-spherical;

[0016] (2) The maximum diameter of the modified spherulites is 20 μm to 500 μm, more preferably 20 μm to 300 μm;

[0017] (3) the central bright area is composed of one or more (i.e., one or more) needle-shaped units, narrow dumbbell-shaped units, or bundle-shaped units;

[0018] (4) The central bright area is radial in shape as a whole;

[0019] (5) The shape of the dark area includes one or more of a double semicircle, an oval, a circle, a jujube-shaped circle, and an oblate circle;

[0020] (6) The area of the extinction dark zone accounts for 50% to 95% of the total area of the mutant spherulites.

[0021] In the above-mentioned ethylene polymer composition, preferably, the mass ratio of the ethylene polymer to the composite organic improver is 100:0.01-10, and the mass ratio of the compound A to the compound B is 1-1000:1-1000.

[0022] More preferably, the mass ratio of the compound A to the compound B in the above-mentioned ethylene polymer composition is 1-100:1-100.

[0023] In the above-mentioned ethylene polymer composition, preferably, the composite organic improver has one or more of the following characteristics:

[0024] (1) The difference ΔW between the peak positions of the characteristic absorption peaks of the NH bending and CN stretching coupling vibrations between the compound A and the compound B in the infrared spectrum within the range of 1600 to 1400 wavenumbers does not exceed 15 wavenumbers;

[0025] (2) The composite organic improver has a characteristic absorption peak of NH stretching vibration in the wave number range of 3500-3100 in the infrared spectrum, and a characteristic absorption peak of carbonyl stretching vibration in the wave number range of 1700-1600;

[0026] (3) The melting point range of the composite organic improver is 100°C to 370°C;

[0027] (4) the composite organic improver is heated from 25° C. to a molten state and then cooled to 25° C. to form a fibrous structure;

[0028] (5) The composite organic improver is characterized by two-stage thermal weight loss in the first-stage thermal weight loss temperature range of 100°C to 300°C and the second-stage thermal weight loss temperature range of 200°C to 450°C under thermogravimetric analysis, or multiple-stage thermal weight loss in the weight loss temperature range of 100°C to 450°C.

[0029] The above-mentioned ethylene polymer composition, more preferably, in the feature (1) of the composite organic improver, the difference ΔW between the peak positions of the NH bending and CN stretching coupled vibration characteristic absorption peaks existing in the infrared spectrum range of 1600 to 1400 wavenumbers between the compound A and the compound B does not exceed 10 wavenumbers.

[0030] More preferably, in the above-mentioned ethylene polymer composition, in the feature (3) of the composite organic improver, the melting point range of the composite organic improver is 200°C to 320°C.

[0031] The above-mentioned ethylene polymer composition is further preferably characterized in that in the feature (1) of the composite organic improver, the difference ΔW between the peak positions of the NH bending and CN stretching coupled vibration characteristic absorption peaks of the compound A and the compound B in the infrared spectrum within the wavenumber range of 1600 to 1400 is no more than 5 wavenumbers.

[0032] The above-mentioned ethylene polymer composition is further preferably characterized in that, in the feature (3) of the composite organic improver, the melting point range of the composite organic improver is 250°C to 300°C.

[0033] The above-mentioned ethylene polymer composition, preferably, the ethylene polymer comprises one or more of an ethylene homopolymer and an ethylene copolymer, and the ethylene copolymer is a copolymer of ethylene and a C3-C10 α-olefin monomer.

[0034] In the above-mentioned ethylene polymer composition, preferably, R1, R2, R3, and R5 are independently selected from methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, phenyl, benzyl, 4-methylbenzyl, 2-methylallyl, cyclohexyl, cyclohexylmethyl 1-Cyclohexylethyl and 2-cyclohexylethyl One or more of;

[0035] The R4 is selected from ethanediyl, propanediyl (including propane-1,2-diyl propane-1,3-diyl), butanediyl, pentanediyl, 2,2-dimethylpropane-1,3-diyl Hexanediyl, heptanediyl, octanediyl, decanediyl, dodecanediyl, cyclohexanediyl (including cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl), methylbenzenediyl (including 4-methylbenzene-1,3-diyl 2-methylbenzene-1,4-diyl), dimethylbenzene-1,4-diyl (including 2,5-dimethylbenzene-1,4-diyl ), benzene diyl (including benzene-1,4-diyl, benzene-1,3-diyl), naphthalene diyl (including naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl), biphenyl diyl (including biphenyl-2,2'-diyl, biphenyl-4,4'-diyl), dimethyl biphenyl (including 3,3'-dimethyl biphenyl-4,4'-diyl ), diphenylmethanediyl (including diphenylmethane-4,4'-diyl ), (1-methylethylidene)biphenyl-4,4'-diyl and 1,3,3-trimethylcyclohexyl-5-yl That is, more preferably, the R4 is selected from ethanediyl, propane-1,2-diyl, propane-1,3-diyl, butanediyl, pentanediyl, 2,2-dimethylpropane-1,3-diyl, hexanediyl, heptanediyl, octanediyl, decanediyl, dodecanediyl, cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl, 4-methylbenzene-1,3-diyl, 2-methylbenzene-1,4-diyl, 2,5-dimethylbenzene-1,4-diyl, benzene-1,3-diyl, benzene-1,4-diyl, benzene-1,3-diyl, cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl, 4-methylbenzene-1,3-diyl, 2-methylbenzene-1,4-diyl, 2,5-dimethylbenzene-1,4-diyl, benzene-1,3-diyl, cyclohexane-1,4-diyl, cyclohexane ... One or more of diphenylmethane, 1,2-diyl, 1,3-diyl, 1,4-diyl, 1,5-diyl, 1,7-diyl, 1,8-diyl, 2,3-diyl, 2,6-diyl, 2,7-diyl, biphenyl-2,2'-diyl, biphenyl-4,4'-diyl, 3,3'-dimethylbiphenyl-4,4'-diyl, diphenylmethane-4,4'-diyl, (1-methylethylidene)biphenyl-4,4'-diyl and 1,3,3-trimethylcyclohexylmethyl-5-yl.

[0036] As a general technical concept, the present invention also provides a method for preparing the above-mentioned ethylene polymer composition, comprising the following steps:

[0037] S1, mixing the ethylene polymer and the composite organic improving agent to obtain a mixed material;

[0038] S2. Melt-blending the mixture at a temperature of 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling the mixture so that compound A and compound B in the composite organic improver induce the molecular chains of the ethylene polymer to form the variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition.

[0039] As a general technical concept, the present invention also provides a method for preparing the above-mentioned ethylene polymer composition, comprising the following steps:

[0040] S1, dividing the ethylene polymer into N parts, 2≤N≤9, and uniformly mixing the first part of the ethylene polymer with the composite organic improver to obtain a first mixed material;

[0041] S2, melt blending the first mixed material at a temperature 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling to obtain a first granular masterbatch;

[0042] S3, uniformly mixing the second portion of the ethylene polymer with the first portion of the granular masterbatch to obtain a second mixed material;

[0043] S4, repeating the process of step S2 and step S3 until the Nth part of the ethylene polymer and the N-1th part of the granular masterbatch are uniformly mixed to obtain the Nth part of the mixed material;

[0044] S5. Melt-blending the Nth portion of the mixed material at a temperature 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling the mixture to obtain an ethylene polymer composition having a crystal morphology of modified spherulites.

[0045] The preparation method of the above-mentioned ethylene polymer composition, preferably, the preparation method has one or more of the following characteristics:

[0046] (1) The cooling is performed at a cooling rate of 10°C / min to 100°C / min to a temperature of 0°C to 40°C;

[0047] (2) The melt blending time is 1 min to 10 min.

[0048] As a general technical concept, the present invention also provides the use of the above-mentioned ethylene polymer composition or the ethylene polymer composition obtained by the above-mentioned preparation method in blow-molded products, cast-molded products, injection-molded products, extrusion-molded products, compression-molded products, vacuum-molded products, rotational-molded products, and blister-molded products.

[0049] In the present invention, the composite organic improver has an appearance of white powder, white lumps, light yellow powder, or light yellow lumps. Spherulites can be observed using a polarizing microscope or, after etching, using a scanning electron microscope. Melt blending can be performed using a mixer or a screw extruder.

[0050] Compared with the prior art, the advantages of the present invention are:

[0051] (1) The ethylene polymer composition of the present invention is composed of a composite organic improver containing compound A and compound B and an ethylene polymer. Compound A and compound B have a good degree of compatibility with the ethylene polymer through self-assembly heterogeneous nucleation, thereby generating variant spherulites, which significantly reduces the turbidity of the ethylene polymer composition, significantly increases the crystallization peak temperature, significantly shortens the half-crystallization time, and significantly improves the mechanical properties. At the same time, the cost of the composite organic improver is low. The composite organic improver of the present invention can control the strength of the intermolecular hydrogen bond on a larger scale by adjusting not only the structure of the substituent groups of the two compounds but also the ratio of the two. The composite organic improver provided by the present invention for the ethylene polymer has a low dosage level, low cost, can significantly improve turbidity, does not yellow and precipitate, can quickly promote nucleation and crystallization, shorten the molding cycle, and has good mechanical properties. In the present invention, when the ethylene polymer is an ethylene copolymer, the turbidity of the composition obtained after adding the composite organic improver is less than 44%, and can usually reach less than 35%; when the ethylene polymer is an ethylene homopolymer, the turbidity of the composition obtained after adding the composite organic improver is less than 70%, and can usually reach less than 60%.

[0052] Unlike conventional heterogeneous nucleation polymer compositions, the ethylene polymer composition of the present invention features a central bright region of the modified spherulites composed of one or more needle-like units, narrow dumbbell-shaped units, or bundled units, which can be radial in shape. The extinction dark regions, rather than the conventional black cross extinction pattern, exhibit shapes such as double semicircles, ovates, rounded shapes, or oblate shapes. The extinction dark regions also account for a large proportion, with their area accounting for 50% to 95% of the total area of the modified spherulites. These modified spherulites are not only directly related to the clarity of the material but also demonstrate good compatibility between additives and the ethylene polymer. The ethylene polymer composition of the present invention features a low heterogeneous nucleus density and large modified spherulites, with a maximum diameter of ≥20 microns. The large size of the modified spherulites further improves transparency.

[0053] (2) In the present invention, the difference ΔW between the peak positions of the characteristic absorption peaks of NH bending and CN stretching coupling vibrations existing in the infrared spectrum range of 1600 to 1400 wavenumbers of compound A and compound B does not exceed 15 wavenumbers, which significantly improves the matching rate between the two compounds and is conducive to obtaining an ethylene polymer composition with lower turbidity, higher crystallization temperature, shorter half-crystallization time, and better mechanical properties.

[0054] (3) In the present invention, the composite organic improver has excellent thermal stability, dissolves in the melt at high processing temperatures, has good compatibility, is evenly dispersed, and has no yellowing or precipitation problems. Compared with commercially available Millad 3988 and HPN-20E, the composite organic improver has the advantage of low dosage level.

[0055] (4) The preparation method of the present invention is not only simple and easy to implement, convenient for industrialization, uses low-cost raw materials, and avoids environmental pollution, but also can effectively improve the performance and economic benefits of the ethylene polymer composition.

[0056] (5) The application of the ethylene polymer composition of the present invention provides a new solution for improving the performance of ethylene polymers, brings significant use value, and can meet unmet needs in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 These are infrared spectra of EX1 of Example 1 of the present invention, EX4 of Example 4, and CT1 of Comparative Example 2.

[0058] Figure 2 This is a spectrum of characteristic absorption peaks of NH bending and CN stretching coupled vibrations in the infrared spectrum range of 1600 to 1400 wavenumbers (displayed as a wavenumber range of 1580 to 1470) for EX1 of Example 1 of the present invention, EX4 of Example 4, CT1 of Comparative Example 2, CT2 of Comparative Example 3, and CT6 of Comparative Example 9.

[0059] Figure 3 This is a graph showing the effects of different ratios of mono- and bis-oxalyl diamide compounds on the infrared spectrum of the composite organic improver in Example 1, Example 2, Comparative Example 2, and Comparative Example 3 of the present invention.

[0060] Figure 4 This is a diagram of the fibrous structure of EX4 according to Example 4 of the present invention observed under a microscope after heat treatment (heating from 25°C to melt and then cooling to 25°C).

[0061] Figure 5 This is a polarizing microscope photograph of the ethylene polymer composition M1 of Example 1 of the present invention.

[0062] Figure 6 This is a polarizing microscope photograph of the ethylene polymer composition M3 of Example 3 of the present invention.

[0063] Figure 7 (a) A polarizing microscope photograph of the ethylene polymer composition M4 of Example 4 of the present invention before etching, and (b) A scanning electron microscope photograph of the ethylene polymer composition M4 after etching.

[0064] Figure 8 This is a polarizing microscope photograph of the ethylene polymer composition M5 of Example 5 of the present invention.

[0065] Figure 9 This is a polarizing microscope photograph of the ethylene polymer composition M6 according to Example 6 of the present invention, and the inset is a partial magnified view.

[0066] Figure 10This is a polarizing microscope photograph of the ethylene polymer composition M7 of Example 7 of the present invention.

[0067] Figure 11 This is a polarizing microscope photograph of the ethylene polymer composition M8 of Example 8 of the present invention.

[0068] Figure 12 This is a polarizing microscope photograph of the pure ethylene copolymer O1 of Comparative Example 1, and the inset is a partial magnified view.

[0069] Figure 13 This is a polarizing microscope photograph of the ethylene polymer composition O2 of Comparative Example 2.

[0070] Figure 14 This is a polarizing microscope photograph of the ethylene polymer composition O3 of Comparative Example 3. DETAILED DESCRIPTION

[0071] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby. The materials and instruments used in the following examples are commercially available, among which Formula (I-1), Formula (I-2), Formula (I-3), Formula (II-1), Formula (II-2), Formula (II-3), and Formula (II-4) can be purchased from J&K Scientific, Chemieliva Pharmaceutical Co., Ltd., chem-space.com, etc., but are not limited thereto, and can also be prepared by reference to literature methods (such as Chem. Eur. J. 2013, 19, 8558-8572).

[0072] In the present invention, the term "ethylene polymer" is preferably selected from one or more of ethylene homopolymers and ethylene copolymers, more preferably high density polyethylene (density 0.941-0.965 g / cm 3 ), medium density polyethylene, low density polyethylene (0.910-0.925g / cm 3 ), linear low density polyethylene, ultra low density polyethylene (density less than 0.910g / cm 3 ), one or more of ultra-high molecular weight polyethylene, metallocene polyethylene, cross-linked polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-butene copolymer, ethylene-octene copolymer and cycloolefin copolymer.

[0073] In the present invention, the terms "additive" and "organic improver" can be used interchangeably.

[0074] In the present invention, the term "turbidity" refers to the percentage of the transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity. The lower the turbidity, the better the gloss, clarity and imaging quality of the material.

[0075] In the present invention, the term "polarizing microscope" is a microscope used to study clarified and unclear anisotropic materials. Its basic structure is to add a polarizing plate above and below the sample stage, and the vibration directions of the two polarizing plates are placed at right angles to each other.

[0076] In the present invention, the term "variant spherulite" refers to a quasi-spherical crystal with a central bright area and surrounding extinct dark areas, with a size of no less than 20 microns, as seen under a polarizing microscope. The composition, morphology, and size of these variant spherulites differ from those of typical black cross extinct spherulites. Under a polarizing microscope, the bright area of these variant spherulites is composed of one or more needle-like units, narrow dumbbell-shaped units, or bundle-like units, forming a radial central structure. The extinct dark areas are surrounded by structures such as bi-semicircular, oval, circular, oblate, or jujube-shaped. The dark areas of these extinct structures are much larger than the bright areas, and the area of the surrounding extinct dark areas accounts for 50% to 95% of the total area of the variant spherulite. Under a polarizing microscope, the formation of the extinct dark areas is due to their minimal effect on the deviation of incident light. That is, light passing through the extinct dark areas is barely deflected, or the angle of deflection is small, such as less than 2.5°. A concrete example is glass, which appears entirely dark under a polarizing microscope. Therefore, the variant spherulites formed by the heterogeneous nucleation of the composite organic improver of the present invention inducing the ethylene polymer macromolecular chain have a macroscopic manifestation of providing a possibility for reducing the turbidity of the ethylene polymer. The variant spherulites are directly related to the clarity of the material.

[0077] In the present invention, the term "extinction dark area ratio" refers to the ratio of the extinction dark area to the total area of the variant spherulite under a polarizing microscope. The extinction dark area and the area of the variant spherulite are estimated by counting the corresponding areas in the polarizing microscope photograph using computer software.

[0078] In this invention, the term "etching" refers to a method of treating samples for electron microscopy observation using an etchant that damages the crystalline and amorphous regions of a semi-crystalline polymer sample to varying degrees, preferentially destroying the loosely packed amorphous regions, thereby more clearly revealing the texture of the crystalline regions. This technique enables clearer observation of the internal structural details of the polymer and the effects of additives on the crystalline regions. The etchant in this invention consists of a strong oxidant and an acid.

[0079] In the present invention, the term "half-crystallization time" refers to the time it takes for a polymer to undergo half of its isothermal crystallization process at a certain temperature. It is a quantitative indicator that describes the crystallization speed and efficiency.

[0080] Example 1

[0081] The present invention discloses an ethylene polymer composition, which is prepared using an ethylene polymer and a composite organic improver as raw materials. The composite organic improver is composed of compound A and compound B. The ethylene polymer composition has a crystal morphology of a modified spherulite, wherein the modified spherulite includes a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area.

[0082] In this embodiment, compound A is a monooxalyl derivative, specifically N,N'-diphenyloxalyl, with a structural formula as shown in formula (I-1), and compound B is a bisoxalyl derivative, specifically N-phenyl-N'-(6-((oxy(phenylamino)acetyl)amino)hexyl)oxalyl, with a structural formula as shown in formula (II-1).

[0083]

[0084] In this embodiment 1, as shown in Table 1 and Figure 5 As shown, the variant spherulites have the following characteristics:

[0085] (1) The overall morphology of the variant spherulites is spherical;

[0086] (2) The maximum diameter of the variant spherulites ranges from 20 μm to 100 μm;

[0087] (3) The central bright area is composed of one or more narrow dumbbell-shaped units;

[0088] (4) The central bright area is generally radial;

[0089] (5) The shapes of the dark areas are mainly round and oblate;

[0090] (6) The area of the dark extinction zone accounts for about 93.0% of the total area of the mutant spherulites.

[0091] In this embodiment, the mass ratio of ethylene polymer to composite organic improver is 100:0.1; the mass ratio of compound A to compound B is 250:750, that is, 25 parts by mass of compound A and 75 parts by mass of compound B are used, and the composite organic improver composed of the two is recorded as EX1.

[0092] In this embodiment, as shown in Table 2 and Figure 1-2 As shown, the composite organic improver has the following characteristics:

[0093] (1) Compound A (CT1) having the structure of formula (I-1) and compound B (CT2) having the structure of formula (II-1) both have characteristic absorption peaks of NH bending and CN stretching coupled vibrations in the infrared spectrum range of 1600 to 1400 wavenumbers. The peak positions W of the two absorption peaks are located at 1515 wavenumbers and 1529 wavenumbers, respectively. The difference ΔW between the two peaks is 14 wavenumbers, which does not exceed 15 wavenumbers.

[0094] (2) EX1 has a characteristic absorption peak of NH stretching vibration in the 3500-3100 wavenumber range of the infrared spectrum, and a characteristic absorption peak of carbonyl stretching vibration in the 1700-1600 wavenumber range;

[0095] (3) The melting point range of EX1 is 230℃~280℃;

[0096] (4) EX1 forms a fibrous structure after heat treatment from 25 °C to a molten state and then cooling to 25 °C;

[0097] (5) The thermogravimetric analysis of EX1 is characterized by the presence of two-stage thermal weight loss, with the first-stage thermal weight loss temperature ranging from 100°C to 300°C and the second-stage thermal weight loss temperature ranging from 280°C to 333°C.

[0098] In this embodiment, the ethylene polymer is a copolymer of ethylene and C4α-olefin monomer (or 1-butene), and its trade name is linear low-density polyethylene polymer. The density of the ethylene polymer is 0.920 g / cm 3 , a medium melt index resin with a melting point of 124°C and a melt flow index of >1g / 10min.

[0099] In this embodiment, EX1 was prepared by the following method:

[0100] S1. In a reactor equipped with a stirrer, a thermometer, a heating device, a dropping device and a condenser, 375.5 g (2.57 mol) of diethyl oxalate (oxalic acid diester) was added, and at room temperature (about 25° C.), a solution consisting of 116.2 g (1 mol) of hexamethylenediamine (diamine) and 116 mL of ethanol was added dropwise to the diethyl oxalate to react to obtain a first reaction mixture;

[0101] S2. 900 mL of N,N-dimethylformamide (DMF) was added to the first reaction mixture and heated until the mixture was dissolved. Then, a solution consisting of 338.9 g (3.64 mol) of aniline (monoamine) and 113 mL of DMF was added and refluxed at 60° C. to 85° C. After completion of the reaction, the obtained second reaction mixture was filtered, washed, and dried for purification and separation to obtain a composite organic improver in the form of a white powder and a block product. The composite organic improver contained compound A and compound B, designated as EX1, with a yield of 92.1%.

[0102] A method for preparing the ethylene polymer composition of the present embodiment comprises the following steps:

[0103] (1) uniformly mixing the ethylene polymer and the composite organic improver in proportion to obtain a mixed material;

[0104] (2) The mixture was melt-blended in a screw extruder at a temperature of 200°C (76°C above the melting point) for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min, so that compound A and compound B in the composite organic modifier induced the molecular chains of the ethylene polymer to form variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition, which was recorded as M1.

[0105] The ethylene polymer composition prepared by the present invention can be widely used in blow molding products, cast molding products, injection molding products, extrusion molding products, compression molding products, vacuum molding products, rotational molding products, and vacuum molding products.

[0106] Table 1 Characteristics of the variant spherulites in Examples 1 to 9 and the spherulites in Comparative Examples 1 to 9

[0107]

[0108]

[0109] Example 2

[0110] An ethylene polymer composition of the present invention and a preparation method thereof are substantially the same as those in Example 1, except that:

[0111] (1) The mass ratio of compound A to compound B is 500:500, and the composite organic improver composed of the two is recorded as EX2;

[0112] (2) As shown in Table 1, the area of the dark extinction region accounts for approximately 85.4% of the total area of the variant spherulites, and the rest is basically the same as in Example 1;

[0113] (3) As shown in Table 2, the melting point range of EX2 is 230°C to 284°C, and the rest is basically the same as Example 1.

[0114] In this embodiment, the preparation method of EX2 is basically the same as the preparation method of EX1, except that: diethyl oxalate is 542.0 g (3.71 mol), aniline is 551.0 g (5.92 mol), and DMF is 276 mL. The obtained composite organic improver is recorded as EX2 with a yield of 96.5%.

[0115] In this embodiment, the ethylene polymer composition using the composite organic improver EX2 is recorded as M2.

[0116] Example 3

[0117] An ethylene polymer composition of the present invention and a preparation method thereof are substantially the same as those in Example 1, except that:

[0118] (1) The mass ratio of compound A to compound B is 750:250, and the composite organic improver composed of the two is recorded as EX3;

[0119] (2) As shown in Table 1 and Figure 6 As shown, the maximum diameter of the variant spherulite is 20 microns to 90 microns, the dark area of the extinction is a double semicircle, and the area of the dark area of the extinction accounts for about 80.7% of the total area of the variant spherulite. The rest is basically the same as Example 1;

[0120] (3) As shown in Table 2, the melting point range of EX3 is 230°C to 288°C, and the rest is basically the same as Example 1.

[0121] In this embodiment, the preparation method of EX3 is basically the same as the preparation method of EX1, except that: diethyl oxalate is 1041.3 g (7.13 mol), aniline is 1187.5 g (12.76 mol), and DMF is 396 mL. The obtained composite organic improver is recorded as EX3 with a yield of 93.0%.

[0122] In this embodiment, the ethylene polymer composition using the composite organic improver EX3 is recorded as M3.

[0123] Example 4

[0124] The present invention discloses an ethylene polymer composition, which is prepared using an ethylene polymer and a composite organic improver as raw materials. The composite organic improver is composed of compound A and compound B. The ethylene polymer composition has a crystal morphology of a modified spherulite, wherein the modified spherulite includes a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area.

[0125] In this embodiment, compound A is the compound N,N'-diphenyloxalyldiamide of formula (I-1), and compound B is the compound N-phenyl-N'-(8-((oxy(phenylamino)acetyl)amino)octyl)oxalyldiamide of formula (II-2).

[0126]

[0127] In this embodiment, as shown in Table 1 and Figure 7 As shown, the variant spherulites have the following characteristics:

[0128] (1) The overall morphology of the variant spherulites is spherical;

[0129] (2) The maximum diameter of the variant spherulites is 184 μm to 230 μm;

[0130] (3) The central bright area is composed of a needle-shaped unit;

[0131] (4) The central bright area is generally radial;

[0132] (5) The shape of the dark area is round or oblate;

[0133] (6) The area of the dark extinction zone accounts for about 94.1% of the total area of the mutant spherulites.

[0134] In this embodiment, the mass ratio of ethylene polymer to composite organic improver is 100:0.1; compound A is 25 parts by mass, and compound B is 75 parts by mass, with a mass ratio of 250:750. The composite organic improver composed of the two is recorded as EX4.

[0135] In this example, the ethylene polymer used is the same as that in Example 1.

[0136] In this embodiment, as shown in Table 2 and Figure 1-2 As shown, the ethylene polymer composition has the following characteristics:

[0137] (1) The peak position W of the characteristic absorption peak of the NH bending and CN stretching coupling vibration present in the infrared spectrum of compound B (CT6) of formula (II-2) in the range of 1600 to 1400 wavenumbers is located at 1516 wavenumbers, and the difference ΔW between the peak position of the corresponding absorption peak of compound A of formula (I-1) is 1 wavenumber and does not exceed 5 wavenumbers;

[0138] (2) EX4 has a characteristic absorption peak of NH stretching vibration in the 3500-3100 wavenumber range of the infrared spectrum, and a characteristic absorption peak of carbonyl stretching vibration in the 1700-1600 wavenumber range;

[0139] (3) The melting point range of EX4 is 200℃~244℃;

[0140] (4) EX4 forms a fibrous structure after heat treatment from 25 °C to a molten state and then cooling to 25 °C;

[0141] (5) The thermogravimetric analysis of EX4 shows two-stage thermal weight loss, with the first stage in the temperature range of 100°C to 300°C and the second stage in the temperature range of 320°C to 370°C.

[0142] In this embodiment, the preparation method of EX4 refers to the preparation method of EX1, except that: the oxalic acid diester is 381.2 g (2.61 mol) of diethyl oxalate, the diamine is 144.3 g (1 mol) of octanediamine, and the monoamine is 346.1 g (3.72 mol) of aniline. Other process conditions remain unchanged. The obtained composite organic improver is recorded as EX4 with a yield of 90.6%.

[0143] A method for preparing the ethylene polymer composition of this embodiment is substantially the same as that of Example 1, except that the composite organic modifier used is EX4, and the obtained ethylene polymer composition is designated as M4.

[0144] Example 5

[0145] The present invention discloses an ethylene polymer composition, which is prepared using an ethylene polymer and a composite organic improver as raw materials. The composite organic improver is composed of compound A and compound B. The ethylene polymer composition has a crystal morphology of a modified spherulite, wherein the modified spherulite includes a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area.

[0146] Compound A is a compound of formula (I-2) N,N'-di(hexadecyl)oxalyl diamide, and compound B is a compound of formula (II-3) N-hexadecyl-N'-(2-((hexadecylamino)(oxo)acetyl)amino)ethyl)oxalyl diamide.

[0147]

[0148] In this embodiment, the characteristics of the variant spherulites are shown in Table 1 and Figure 8 shown.

[0149] In this embodiment, the mass ratio of the ethylene polymer to the composite organic improver is 100:0.1. The mass ratio of compound A to compound B is 250:750. The composite organic improver composed of the two is designated as EX5.

[0150] In this example, the ethylene polymer used is the same as that in Example 1.

[0151] In this embodiment, the characteristics of the composite organic improver in the ethylene polymer composition are shown in Table 2.

[0152] In this embodiment, the preparation method of EX5 refers to the preparation method of EX1, except that: the oxalic acid diester is 365.4 g (2.50 mol) of diethyl oxalate, the diamine is 60.1 g (1 mol) of ethylenediamine, and the monoamine is 965.8 g (4 mol) of hexadecylamine. Other process conditions remain unchanged. The obtained composite organic improver is recorded as EX5 with a yield of 92.5%.

[0153] A method for preparing the ethylene polymer composition of this embodiment is substantially the same as that of Example 1, except that the composite organic modifier used is EX5, and the resulting ethylene polymer composition is designated as M5.

[0154] Table 2 Composition and performance results of the composite organic improver in Examples 1 to 5

[0155]

[0156] Example 6

[0157] The present invention discloses an ethylene polymer composition, which is prepared using an ethylene polymer and a composite organic improver as raw materials. The composite organic improver is composed of compound A and compound B. The ethylene polymer composition has a crystal morphology of a modified spherulite, wherein the modified spherulite includes a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area.

[0158] Compound A is composed of the compound N,N'-diphenylethanediamide of formula (I-1) and the compound N,N'-dihexylethanediamide of formula (I-3), and compound B is composed of the compound N-phenyl-N'-(6-((oxy(phenylamino)acetyl)amino)hexyl)ethanediamide of formula (II-1) and the compound N-hexyl-N'-(6-((hexylamino)(oxy)acetyl)amino)hexyl)ethanediamide of formula (II-4).

[0159]

[0160] In this embodiment, the characteristics of the variant spherulites are shown in Table 1 and Figure 9 shown.

[0161] In this embodiment, the mass ratio of ethylene polymer to composite organic improver is 100:0.1, the mass composition of compound A of formula (I-1), compound A of formula (I-3), compound B of formula (II-1), and compound B of formula (II-4) is 120:180:600:100, and the composite organic improver composed of the same is designated as EX6.

[0162] In this example, the ethylene polymer used is the same as that in Example 1.

[0163] In this embodiment, the characteristics of the composite organic improver in the ethylene polymer composition are shown in Table 3.

[0164] In this embodiment, EX6 is prepared by the following method:

[0165] S1. In a reactor equipped with a stirrer, a thermometer, a heating device, a dropping device and a condenser, 438.4 g (3 mol) of diethyl oxalate was added, and at room temperature (about 25° C.), a solution consisting of 116.2 g (1 mol) of hexamethylenediamine and 116 mL of ethanol was added dropwise to the diethyl oxalate to react to obtain a first reaction mixture;

[0166] S2, 900mL DMF was added to the first reaction mixture, heated until the mixture was dissolved, then a solution consisting of 202.4 grams (2 mol) of hexylamine and 100mL of DMF was added and the mixture was refluxed at 60°C to 85°C. After completion of the reaction, a solution consisting of 279.4 grams (3 mol) of aniline and 140mL of DMF was added and the mixture was refluxed again at 60°C to 85°C. After completion of the reaction, the obtained second reaction mixture was filtered, washed, and dried for refining and separation to obtain a composite organic improver, which was a white powder and a block product. The composite organic improver contained compound A and compound B and was designated as EX6 with a yield of 91.5%.

[0167] A method for preparing the ethylene polymer composition of this embodiment is substantially the same as that of Example 1, except that the composite organic modifier used is EX6, and the obtained ethylene polymer composition is designated as M6.

[0168] Table 3 Composition and performance results of the composite organic improver in Example 6

[0169]

[0170]

[0171] Note: When the two components of the composite organic improver contain multiple compounds, take the average value W of compound A and compound B at the amide II band peak position, and then calculate the difference △W.

[0172] Example 7

[0173] An ethylene polymer composition of the present invention is substantially the same as Example 1, except that the characteristics of the variant spherulites are shown in Tables 1 and Figure 10 As shown, the variant spherulite includes a central bright area and an extinction dark area. The extinction dark area surrounds the central bright area. The area of the extinction dark area accounts for about 76.6% of the total area of the variant spherulite. The rest is basically the same as Example 1.

[0174] A method for preparing the ethylene polymer composition of the present embodiment comprises the following steps:

[0175] (1) uniformly mixing the ethylene polymer and EX1 in proportion to obtain a mixed material;

[0176] (2) The mixture was melt-blended in a screw extruder at 200°C for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 30°C / min, so that compound A and compound B in the composite organic modifier induced the molecular chains of the ethylene polymer to form variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition, which was recorded as M7.

[0177] Example 8

[0178] An ethylene polymer composition of the present invention is substantially the same as Example 1, except that the characteristics of the variant spherulites are shown in Tables 1 and Figure 11 As shown, the variant spherulite includes a central bright area and an extinction dark area. The extinction dark area surrounds the central bright area, and the extinction dark area accounts for about 67.8%. The rest is basically the same as Example 1.

[0179] A method for preparing the ethylene polymer composition of the present embodiment comprises the following steps:

[0180] (1) uniformly mixing the ethylene polymer and EX1 in proportion to obtain a mixed material;

[0181] (2) The mixture was melt-blended in a screw extruder at 200°C for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 10°C / min, so that compound A and compound B in the composite organic modifier induced the molecular chains of the ethylene polymer to form variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition, which was recorded as M8.

[0182] Example 9

[0183] An ethylene polymer composition of the present invention is substantially the same as that of Example 1, except that the characteristics of the modified spherulites are shown in Table 1.

[0184] A method for preparing the ethylene polymer composition of the present embodiment comprises the following steps:

[0185] (1) 1 part by mass of ethylene polymer and 0.1 part by mass of EX1 were uniformly mixed in a mass ratio of 100:10 to obtain a mixed material;

[0186] (2) The mixture was melt-blended in a screw extruder at 200°C for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min to obtain a granular masterbatch, which was designated as H1.

[0187] (3) uniformly mixing 99 parts by mass of the ethylene polymer with 1.1 parts by mass of the granular masterbatch H1 to obtain a mixed material;

[0188] (4) The mixture was melt-blended in a screw extruder at 200°C for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min, so that compound A and compound B in the composite organic modifier masterbatch induced the molecular chains of the ethylene polymer to form variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition, which was recorded as M9.

[0189] Comparative Example 1

[0190] In this comparative example, no additives were used and the ethylene polymer used was the same as in Example 1. The pure ethylene copolymer was designated as O1. The spherulites formed by crystallization of the pure ethylene copolymer O1 after melting were typical black cross matt spherulites with a size of less than 10 microns. Figure 12 shown.

[0191] Comparative Example 2

[0192] A monooxalyl diamide derivative is used as an additive, specifically the compound N,N'-diphenyloxalyl diamide, as shown in formula (I-1), and is denoted as CT1.

[0193] An ethylene polymer composition, wherein the used ethylene polymer is the same as that in Example 1, and the preparation method of the composition comprises the following steps:

[0194] (1) uniformly mixing the ethylene polymer and CT1 at a mass ratio of 100:0.1 to obtain a mixed material;

[0195] (2) The mixture was melt-blended in a screw extruder at 200°C (76°C above the melting point) for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min to obtain an ethylene polymer composition, which was recorded as O2.

[0196] The spherulites formed by the ethylene polymer composition O2 using the additive CT1 after melting and crystallization are similar in shape and size to those of the pure ethylene copolymer O1. Figure 13 shown.

[0197] Comparative Example 3

[0198] A bisoxalyl diamide derivative, specifically the compound N-phenyl-N'-(6-((oxy(phenylamino)acetyl)amino)hexyl)oxalyl diamide, as shown in formula (II-1), is denoted as CT2.

[0199] An ethylene polymer composition using additive CT2, the ethylene polymer used is the same as in Example 1, and the preparation method is the same as in Comparative Example 2, to obtain an ethylene polymer composition, denoted as O3. The spherulites formed by crystallization after melting of the ethylene copolymer composition O3 are mainly homogeneous nucleation. It can be observed that although the additive CT2 forms a fibrous structure, its morphology and size are different from those of the modified spherulites, and no modified spherulites are formed. Figure 14 shown.

[0200] Comparative Example 4

[0201] Commercially available Millad 3988 is designated as CT3.

[0202] An ethylene polymer composition using additive CT3 was prepared by the same method as in Example 1 and comparative example 2 to obtain an ethylene polymer composition, designated O4. No aberrant spherulites were formed upon crystallization of the ethylene copolymer composition O4 after melting.

[0203] Comparative Example 5

[0204] An ethylene polymer composition using additive CT3, wherein the ethylene polymer used is the same as that in Example 1, and the preparation method thereof comprises the following steps:

[0205] (1) uniformly mixing the ethylene polymer and CT3 in a ratio of 100:0.2 to obtain a mixed material;

[0206] (2) The mixture was melt-blended in a screw extruder at 200°C (76°C above the melting point) for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min to obtain an ethylene polymer composition, which was designated as O5.

[0207] The ethylene copolymer composition O5 containing the additive CT3 did not generate modified spherulites after melting and crystallization.

[0208] Comparative Example 6

[0209] The commercially available HPN-20E is designated as CT4.

[0210] An ethylene polymer composition using additive CT4 was prepared by the same method as in Example 1 and comparative example 2 to obtain an ethylene polymer composition, designated O6. The ethylene copolymer composition O6 did not form aberrant spherulites upon crystallization after melting.

[0211] Comparative Example 7

[0212] An ethylene polymer composition using additive CT4 was prepared by the same method as in Example 1 and comparative example 5 to obtain an ethylene polymer composition, designated O7. No aberrant spherulites were formed upon crystallization of the ethylene copolymer composition O7 after melting.

[0213] Comparative Example 8

[0214] Commercially available calcium carbonate is designated as CT5.

[0215] An ethylene polymer composition using additive CT5 was prepared by the same method as in Example 1 and comparative example 5 to obtain an ethylene polymer composition, designated O8. The ethylene copolymer composition O8 did not form aberrant spherulites upon crystallization after melting.

[0216] Comparative Example 9

[0217] A bisoxalyl diamide derivative, specifically the compound N-phenyl-N'-(8-((oxy(phenylamino)acetyl)amino)octyl)oxalyl diamide, as shown in formula (II-2), is denoted as CT6.

[0218] An ethylene polymer composition containing the additive CT6 was prepared using the same ethylene polymer as in Example 1 and the same method as in Comparative Example 2, yielding an ethylene polymer composition designated O9. Spherulites formed by melting and crystallizing the ethylene copolymer composition O9 were primarily homogeneous nucleation. Although CT6 could also form a fibrous structure like CT2, it did not form modified spherulites.

[0219] Characterization results of composite organic improvers in ethylene polymer compositions:

[0220] In Examples 1-9, the composite organic improvers EX1 to EX6 were tested for their melting points by a differential scanning calorimeter and their thermal weight loss temperatures by a thermogravimetric analyzer (nitrogen atmosphere, heating rate of 10°C / min). The test results are shown in Tables 2-3. The results show that the composite organic improvers composed of different mass fractions of compound A and compound B have higher melting points and higher thermal weight loss temperatures. By adjusting the structure of the compound substituent group and the mass ratio of compounds A and B, the thermal performance parameters and the strength of the intermolecular hydrogen bonding can be regulated.

[0221] Figure 1The infrared spectra of EX1, EX4, and CT1 were obtained using a Fourier transform infrared spectrometer. The results show that the composite organic modifier composed of compound A and compound B has a narrow and strong absorption peak in the infrared spectrum range of 3500-3100 wavenumbers, which is attributed to the characteristic absorption peak of NH stretching vibration, also known as the amide A band; a narrow and strongest absorption peak in the wavenumber range of 1700-1600 wavenumbers, which is attributed to the characteristic absorption peak of carbonyl stretching vibration, also known as the amide I band; and a narrow and strong absorption peak in the wavenumber range of 1600-1400 wavenumbers, which is attributed to the characteristic absorption peak of coupled vibration of NH bending and CN stretching, also known as the amide II band.

[0222] The oxalyl group exhibits a specific coplanar structure that facilitates the formation of a quasi-conjugated proton system. The NH bending and CN stretching coupled vibrations (amide II band) are located closer to the substituent groups (R1, R2, R3, R4, and R5) along the molecular axis, making them more susceptible to their influence. In other words, the amide II band is particularly sensitive to polymorphism caused by differences in molecular chain conformation. Therefore, the NH bending and CN stretching coupled vibration absorption peaks were selected as indicators for determining the quality of the additives used in this invention.

[0223] Different substituent groups (R1, R2, R3, R4, R5) result in varying degrees of twisting of the molecular chains of Compound A and / or Compound B, which can cause the fully extended zigzag conformation to tilt or twist. Increased chain conformational twisting affects the planarity of the quasi-conjugated system to a certain extent, thereby separating different types of superstructures or developing different subcrystalline states. This tilt or twisting of the coplanar structure, influenced by the substituent groups, affects the matching between the two components of the composite organic modifier and further influences self-assembly and the resulting fibrous structure. A significant macroscopic manifestation of this effect is the shift in the position of the amide II band. This polymorphic difference caused by the substituent groups also affects the formation of variant spherulites of ethylene polymers growing with the composite organic modifier as the crystal nucleus, further affecting their crystallization behavior and macroscopic properties. Compounds A and B with higher matching rates are more suitable for the growth of ethylene polymer molecular chains into variant spherulites. Therefore, in order to obtain an ethylene polymer composition with a higher crystallization temperature, a shorter half-crystallization time, a lower turbidity, and more significant mechanical properties, the difference ΔW between the peak positions of the NH bending and CN stretching coupled vibration characteristic absorption peaks of compound A and compound B in the infrared spectrum range of 1600 to 1400 wavenumbers is preferably not more than 15 wavenumbers, more preferably not more than 10 wavenumbers, and even more preferably not more than 5 wavenumbers, so as to promote a higher matching rate between compound A and compound B.

[0224] The monooxalyl diamide components in EX1 and EX4 are both compounds of formula (I-1), the bisoxalyl diamide components are compounds of formula (II-1) and (II-2), respectively, and CT1, CT2, and CT6 have the structures of formula (I-1), formula (II-1), and formula (II-2), respectively. Figure 2 This is the infrared spectrum of EX1, EX4 and their components CT1, CT2, CT6 in the 1600-1400 wavenumber range (displayed as 1580-1470 wavenumber range). Figure 2 The characteristic absorption peaks of NH bending and CN stretching coupling vibrations in the 1600-1400 wavenumber range for CT1 and CT2 are located at 1515 and 1529 wavenumbers, respectively. The difference in the peak positions is 14 wavenumbers, indicating a significant distance between the two peaks. Furthermore, the two-component composition EX1 exhibits a shoulder peak at 1515 wavenumber. Compared to EX1, the characteristic absorption peak of NH bending and CN stretching coupling vibrations for CT6, compound B in EX4, is located at 1516 wavenumber. This peak position differs from that of CT1 by 1 wavenumber, a smaller difference of 1 wavenumber, and the peaks are nearly identical. The absorption peak of the two-component composition EX4 is also located at 1515 wavenumber, indicating a higher matching rate between the components. This indicates that ethylene polymer compositions using EX4 are more likely to exhibit higher crystallization temperatures, shorter half-crystallization times, lower turbidity, and superior mechanical properties.

[0225] Another beneficial effect of the higher matching rate is that the composite organic improver forms a developed fibrous structure after heat treatment, with the diameter of the single fiber ranging from 0.1 to 10 microns, such as Figure 4 Conversely, the well-developed fibrous structure also indicates a high matching rate between compound A and compound B.

[0226] Figure 3 The results show the effect of varying the ratio of mono- and dioxadiamine compounds on intermolecular hydrogen bonding in the composite organic modifier. The results show that the intensity of the characteristic absorption peak of the NH stretching vibration of the composite organic modifier increases with increasing the mass fraction of compound B. This indicates that adjusting the ratio of compound A to compound B can adjust the strength of intermolecular hydrogen bonding.

[0227] As shown in Table 4, CT1 is a monooxalyl diamide compound with a lower cost, while CT2 and CT6 are bisoxalyl diamide compounds with a higher cost. Due to the beneficial effects of the one-pot synthesis process, EX1 to EX3 have lower costs compared to CT2, and EX4 has lower costs compared to CT6.

[0228] Table 4 Comparison of the cost of the composite organic improver in the ethylene polymer composition of the present invention and the comparative example

[0229]

[0230]

[0231] Characterization results of ethylene polymer compositions:

[0232] An injection molding machine was used to injection mold the ethylene polymer composition into a 1 mm thick standard transmittance haze sheet in accordance with GB / T 17037.3-2003, into a 4 mm thick standard tensile bar in accordance with GB / T 1040.2-2006, and into a 4 mm thick standard bending bar and a standard notched impact bar in accordance with GB / T 17037.1-2019. It should be noted that the metal mold used in the injection molding machine is hollow and connected to a circulating oil bath for temperature control. The mold is equipped with a meter that can measure the cooling rate. Under the influence of the circulation of different oil bath temperatures, the temperature of the metal mold varies, resulting in different cooling rates for the ethylene polymer melt injected into the mold by the injection molding machine, thereby enabling the preparation of ethylene polymer composition bars at different cooling rates.

[0233] The crystallization and melting parameters of each ethylene polymer composition were measured using a differential scanning calorimeter (DSC) in accordance with GB / T 19466.3-2004. The DSC non-isothermal temperature program for obtaining the peak crystallization temperature (Tc) was as follows: a sample was collected from a target portion, and under nitrogen protection, the temperature was raised from 25°C to 200°C at a rate of 10°C / min, held at 200°C for 3 minutes, and then cooled to 25°C at a rate of 10°C / min. The DSC isothermal temperature program for obtaining the half-crystallization time was as follows: a sample was collected from a target portion, and under nitrogen protection, the temperature was raised from 25°C to 160°C at a rate of 50°C / min, held at 160°C for 5 minutes, and then cooled to 108.5°C at a rate of 50°C / min, followed by isothermal crystallization for 30 minutes.

[0234] Optical properties testing was conducted according to GB / T 2410-2008 for light transmittance and turbidity. Tensile properties testing was conducted according to GB / T 1040.2-2006 for tensile properties. Flexural properties testing was conducted according to GB / T 9341-2008. Impact properties testing was conducted according to GB / T 1843-2008 for notched Izod impact strength.

[0235] When preparing ethylene polymer compositions M1-M9, it was found that the composite organic improvers EX1-EX6 dissolved in the ethylene copolymer melt at high temperature, resulting in a transparent melt with good compatibility and uniform dispersion. During the subsequent cooling period, the crystallization of the ethylene copolymer was a coexistence mode of heterogeneous nucleation as the main and homogeneous nucleation as the auxiliary, such as Figure 5-11As shown. Unlike the effects of traditional heterogeneous nucleation, which increase the nucleation density and reduce the size of spherulites (Table 1), the composition of the composite organic improver heterogeneous nucleation and ethylene polymer of the present invention has the effect of reducing the nucleation density and increasing the size of the variant spherulites. The composite organic improver induces the ethylene copolymer molecular chains to form variant spherulites through self-assembled heterogeneous nucleation. The areas between the variant spherulites are small spherulites formed by homogeneous nucleation of the ethylene copolymer.

[0236] Table 1 lists the morphological characteristics of the example compositions and the comparative example compositions. Figure 5-Figure 11 and Figure 12-14 The morphologies of some embodiments and some comparative examples under a polarizing microscope are shown respectively. The ethylene polymer compositions M1-M9 using a variety of different composite organic modifiers all show a crystalline morphology of variant spherulites under a polarizing microscope. Such variant spherulites mainly include a central bright area and an extinction dark area, and the extinction dark area surrounds the central bright area. The characteristics of such variant spherulites are as follows: (1) The overall morphology of the variant spherulites of the ethylene polymer compositions M1-M9 in the embodiments is spherical or quasi-spherical, while in the prior art, including the comparative example, as the small spherulites of the ethylene polymer grow, adjacent small spherulites collide to form irregular polygonal spherulites; (2) The maximum diameter of the variant spherulites in the embodiments is in the range of 20 microns to 500 microns, which is larger than the diameter of the pure ethylene copolymer spherulites in comparative example 1, and the diameter of the spherulites tends to increase, while the use of existing additives (such as CT1-CT6) increases the crystal nuclei for the ethylene polymer, and the diameter of the spherulites tends to decrease; (3) The central bright area of the variant spherulites in the embodiments is composed of one or more The invention is composed of needle-shaped units, narrow dumbbell-shaped units or bundle-shaped units, while the bright area of the spherulites in the prior art, including the comparative examples, is not in the central position, the relative area of the bright area is larger and mostly petal-shaped; (4) the central bright area of the variant spherulites in the embodiment extends radially outward from the center; (5) the shape of the extinction dark area of the variant spherulites in the embodiment includes one or more of a double semicircle, an oval, a circle, a jujube-shaped circle and an oblate circle, which is significantly different from the black cross extinction pattern in the prior art; (6) another significant feature of the variant spherulites in the embodiment regarding the extinction dark area is the proportion of the extinction dark area to the total area of the variant spherulites, which is 50% to 95%, which is greater than the proportion of the extinction dark area of the spherulites in the comparative examples.

[0237] In the present invention, the composition, morphology and size of the variant spherulites are different from the traditional black cross matte spherulites in the comparative example, and also different from the spherulites in the prior art. A typical variant spherulite is as follows Figure 5As shown, the spherical variant spherulites with a maximum diameter of 20-100 μm mainly include two parts: a central bright area and an extinction dark area. The extinction dark area surrounds the central bright area. The central bright area is mainly distributed in the 3π / 4 or 7π / 4 angle area, and the bright area is significantly weakened radially. There is almost no bright area in other angle areas, and the extinction dark area accounts for about 93.0%. Figure 6 The central bright area of the medium-variant spherulite is mainly distributed at angles of π / 4 and / or 5π / 4, and the bright area is significantly weakened radially, and there is almost no bright area in other angle areas.

[0238] In the composition M4 using EX4, the diameter of one variant spherulite was 184 μm, as shown in FIG. Figure 7 (a), this diameter was also confirmed in subsequent scanning electron microscopy results, as shown in Figure 7 As shown in Figure (b), the results also show that the morphology of the modified spherulites is oblate. Under the same conditions, the spherulites formed by homogeneous nucleation of ethylene copolymer molecular chains are less than 10 microns in size.

[0239] Based on the beneficial effects of the formed variant spherulites, the results of the crystallization peak temperature, half-crystal time, light transmittance, turbidity, tensile properties, bending properties, and impact properties of each ethylene polymer composition sample are shown in Tables 5-6.

[0240] Table 5 Performance results of ethylene polymer compositions of Examples 1-4 and Comparative Examples 1-9

[0241]

[0242]

[0243] The ethylene polymer compositions prepared in the above examples did not exhibit undesirable yellowing and precipitation after processing.

[0244] As shown in Table 5, compared to pure ethylene copolymers without additives, the ethylene copolymers containing composite organic modifiers EX1-EX3 exhibited crystallization temperatures exceeding 5°C higher, half-crystallization times within 30 seconds, and turbidity values below 44%, with a turbidity reduction of 44-49%. The increases in tensile strain at break and notched impact strength, representing toughness, were 7-15% and 7-9%, respectively, while the flexural strength, representing rigidity, was slightly improved. Polymer rigidity and toughness are generally in conflict; increasing toughness typically results in a decrease in rigidity. The improved rigidity and toughness of the compositions of the present invention demonstrate that the ethylene polymer compositions containing composite organic modifiers possess superior mechanical properties. Furthermore, the increase in tensile strength reached approximately 5%, also demonstrating the superior mechanical properties of the compositions. Compared to commercially available products (Millad 3988, HPN-20E, and CaCO3), the ethylene polymer compositions M1-M3 of the present invention exhibit significant improvements in crystallization temperature, half-crystallization time, transmittance, turbidity, tensile strength, tensile strain at break, flexural strength, and notched impact strength. More beneficially, the composite organic modifier used in the ethylene polymer composition of the present invention achieves superior results while requiring a lower dosage than commercially available products (Millad 3988, HPN-20E, and CaCO). Compared to pure monooxalyldiamide compound CT1 and pure bisoxalyldiamide compound CT2, the composite organic modifier employed in the present invention demonstrates significant improvements in the crystallization temperature, half-crystallization time, light transmittance, turbidity, tensile strength, tensile strain at break, and notched impact strength of the ethylene copolymer.

[0245] As previously mentioned, compared to EX1, the two components in EX4 have a higher matching rate. Table 5 shows that, compared to EX1, the highly matched composition M4, composed of EX4 and an ethylene copolymer, further increases crystallization temperature, shortens half-crystallization time, reduces turbidity, and improves mechanical properties, including tensile strength, tensile strain at break, and notched impact strength. This indicates that the difference ΔW between the peak positions of the characteristic absorption peaks of the NH bending and CN stretching coupling vibrations present in the infrared spectrum range of 1600-1400 for the two components of the composite organic modifier correlates with their enhanced crystallization, reduced turbidity, and improved mechanical properties in the ethylene copolymer. Therefore, to achieve an ethylene polymer composition with a higher crystallization temperature, shorter half-crystallization time, lower turbidity, and superior mechanical properties, the difference ΔW between the peak positions of the characteristic absorption peaks of the NH bending and CN stretching coupling vibrations present in the infrared spectrum range of 1600-1400 for Compound A and Compound B of the present invention is preferably no more than 15 wavenumbers, more preferably no more than 10 wavenumbers, and even more preferably no more than 5 wavenumbers, to further improve the matching rate between Compounds A and B. More beneficially, at the same dosage, the composite organic improver used in the present invention not only has a better effect, but also has a lower cost than the pure bisoxalyl diamide compound.

[0246] Table 6 Performance results of the ethylene polymer compositions of Examples 5-6

[0247]

[0248] Table 6 further illustrates that the composite organic modifier of the present invention has the beneficial effects of promoting crystallization, shortening the molding cycle, reducing turbidity, and significantly increasing toughness without reducing rigidity in ethylene copolymers, while also having the advantages of low dosage and low cost. It also illustrates the important role of the difference ΔW between the amide II band peak positions between the components in the preferred compounds A and B.

[0249] Figure 5 、 Figure 10 and Figure 11 Polarizing microscope images of ethylene polymer compositions M1, M7, and M8, respectively. Combined with Table 7, it can be seen that as the cooling rate increases, the proportion of the extinction dark region of the modified spherulites in the ethylene polymer compositions increases, while the turbidity of the ethylene copolymer compositions gradually decreases. This indicates that the cooling rate primarily affects the central bright region and the proportion of the extinction dark region of the modified spherulites, and thus the turbidity of the compositions, but does not affect the formation of modified spherulites.

[0250] Table 7 Transmittance and turbidity results of ethylene polymer compositions prepared at different cooling rates

[0251]

[0252] As shown in Example 9, the mass ratio of ethylene polymer to EX1 in composition M9 is the same as that in composition M1, both being 100:0.1. The only difference between the two is that in composition M9, a portion of the ethylene polymer and the composite organic improver are first preformed into a masterbatch, and then the masterbatch is combined with another portion of the ethylene polymer to form a composite. As can be seen from Tables 1 and 7, the number of melt blending and cooling cycles does not hinder the formation of variant spherulites and has little effect on the composition, morphology, and size of the variant spherulites. Furthermore, since increasing the number of melt blending and cooling cycles improves the dispersibility of the composite organic improver in the ethylene polymer, the proportion of extinction dark areas in the variant spherulites increases slightly, and the turbidity of the corresponding composition decreases slightly. Since the composite organic improver has a powdery appearance and is easily dispersed at the production site, forming a masterbatch can avoid this drawback, while also helping to reduce operational difficulty and improve product performance.

[0253] Example 10

[0254] An ethylene polymer composition of the present invention is substantially the same as that of Example 1, except that:

[0255] (1) In this embodiment, the ethylene polymer is an ethylene homopolymer, trade name high-density polyethylene, and the density of the ethylene homopolymer is 0.963 g / cm 3 , a high melt index resin with a melting point of 130°C and a melt flow index of ≥7g / 10min;

[0256] (2) Among the characteristics of the mutant spherulites, the area of the extinction dark zone accounts for 65.5% of the total area of the mutant spherulites.

[0257] A method for preparing an ethylene polymer composition of the present invention comprises the following steps:

[0258] (1) uniformly mixing ethylene homopolymer and EX1 at a mass ratio of 100:0.1 to obtain a mixed material;

[0259] (2) The mixture was melt-blended in a screw extruder at a temperature of 200°C (70°C above the melting point) for 3 minutes, and then cooled to room temperature (25°C) at a cooling rate of 50°C / min, so that compound A and compound B in the composite organic improver induced the molecular chains of the ethylene homopolymer to form variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition, which was recorded as N1.

[0260] Example 11

[0261] An ethylene polymer composition of the present invention is substantially the same as Example 10, except that:

[0262] (1) The mass ratio of compound A to compound B in the composite organic improver is 500:500, denoted as EX2;

[0263] (2) The melting point range of the composite organic improver is 230℃-284℃;

[0264] (3) Among the characteristics of the variant spherulites, the area of the extinction dark zone accounts for 60.3% of the total area of the variant spherulites.

[0265] A method for preparing an ethylene polymer composition of the present invention is substantially the same as that of Example 10, except that the composite organic improver used is EX2. The resulting ethylene polymer composition is designated as N2.

[0266] Example 12

[0267] An ethylene polymer composition and its application of the present invention are substantially the same as those of Example 4, except that:

[0268] (1) In this embodiment, the ethylene polymer is an ethylene homopolymer, trade name high-density polyethylene, and the density of the ethylene homopolymer is 0.963 g / cm 3 , a high melt index resin with a melting point of 130°C and a melt flow index of ≥7g / 10min.

[0269] (2) Among the characteristics of the variant spherulites, the area of the extinction dark zone accounts for 67.8% of the total area of the variant spherulites.

[0270] A method for preparing an ethylene polymer composition of the present invention is substantially the same as that of Example 10, except that the composite organic improver used is EX4. The resulting ethylene polymer composition is designated as N3.

[0271] Comparative Example 10

[0272] In this comparative example, no additives were used, and the ethylene polymer used was the same as in Example 10. The pure ethylene homopolymer was designated as P1. The spherulites formed by crystallization of the pure ethylene homopolymer P1 after melting were typical black cross matt spherulites with a size of less than 10 μm.

[0273] Comparative Example 11

[0274] An ethylene polymer composition containing additive CT2 was prepared in the same manner as in Example 10 to obtain an ethylene polymer composition, designated P2. The ethylene homopolymer composition P2 did not form aberrant spherulites upon crystallization after melting.

[0275] Comparative Example 12

[0276] An ethylene polymer composition containing additive CT4 was prepared in the same manner as in Example 10 to obtain an ethylene polymer composition, designated P3. No aberrant spherulites were formed upon crystallization of the ethylene homopolymer composition P3 after melting.

[0277] The characterization of the ethylene homopolymer composition is the same as that of the ethylene copolymer composition.

[0278] During the preparation of compositions N1-N3, it was found that the composite organic modifiers EX1, EX2, and EX4 dissolved in the ethylene homopolymer melt at high temperatures, resulting in a clear, well-compatible, and uniformly dispersed melt. During the subsequent cooling period, the crystallization of the ethylene homopolymer exhibited a coexistence of heterogeneous nucleation, primarily with homogeneous nucleation as a supplement. The heterogeneous nucleation of the composite organic modifiers induced the formation of modified spherulites within the ethylene homopolymer molecular chains. The composition, morphology, and size of these modified spherulites differed from traditional black cross-shaped extinction spherulites under a polarizing microscope. These modified spherulites primarily consisted of a central bright region and an extinction dark region, with the extinction dark region surrounding the central bright region. The maximum diameter of the modified spherulites ranged from 20 to 500 microns. The central bright region consisted of one or more needle-like units, narrow dumbbell-shaped units, or bundles of units, arranged in a radial pattern. The morphology surrounding the extinction dark region was primarily round and oblate, with the extinction dark region comprising 50% to 95%. The evaluation results for each ethylene homopolymer composition sample are shown in Table 8.

[0279] Table 8 Evaluation results of ethylene homopolymer compositions

[0280]

[0281] The composite organic improver and ethylene homopolymer do not exhibit undesirable yellowing and precipitation after processing.

[0282] As shown in Table 8, compared to pure ethylene homopolymer without additives, the ethylene homopolymer composition containing the composite organic modifier exhibited a 0.6-0.7°C increase in crystallization temperature, a half-crystallization time of less than 40 seconds, and a turbidity value below 65%, a 23-25% decrease in turbidity. The tensile strain at break and notched impact strength, indicators of toughness, increased by 9-17% and 12-17%, respectively, while the flexural strength, an indicator of rigidity, was slightly improved. Compared to the comparative example of pure bisoxalyl diamide compound CT2, the ethylene homopolymer composition containing the composite organic modifier exhibited significant improvements in crystallization temperature, half-crystallization time, transmittance, turbidity, tensile strain at break, and notched impact strength. This significant improvement helps address the market's concerns about the poor impact resistance of ethylene homopolymer injection molded products produced using the Unipol process.

[0283] As shown in Table 8, compared with EX1, the composition N3 composed of high-matching EX4 and ethylene homopolymer has a further increased crystallization temperature, a further shortened half-crystallization time, a further reduced turbidity, and further improved mechanical properties.

[0284] In general, the ethylene polymer composition of the present invention, wherein the composite organic modifier heterogeneously nucleates and induces the ethylene polymer molecular chains to form variant spherulites, has the following advantages: (1) the composite organic modifier has the beneficial effects of promoting crystallization, shortening the molding cycle, reducing turbidity, and increasing mechanical properties in the ethylene polymer; (2) the beneficial effects of the composite organic modifier in promoting crystallization, shortening the molding cycle, reducing turbidity, and increasing mechanical properties in the ethylene copolymer are further enhanced by optimizing the peak position difference ΔW of the infrared spectrum NH bending and CN stretching coupled vibration characteristic absorption peaks to compound A and compound B; and (3) the composite organic modifier used has the advantages of small dosage and low cost.

[0285] The above description is only a preferred embodiment of the present invention and does not constitute any formal limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solution of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An ethylene polymer composition, characterized in that The ethylene polymer composition is prepared from ethylene polymer and a composite organic improver as raw materials, wherein the composite organic improver is composed of compound A and compound B, wherein compound A is one or more monooxalyl diamide derivatives, and compound B is one or more bisoxalyl diamide derivatives; the ethylene polymer composition has a crystal morphology of variant spherulites, wherein the variant spherulites include a central bright area and an extinction dark area, wherein the extinction dark area surrounds the central bright area. The structural formula of the monooxalyl diamide derivative is shown in formula (I): The structural formula of the bisoxalyl diamide derivative is shown in formula (II): Wherein, R1, R2, R3, R4 and R5 are independently selected from one of hydrocarbon groups having 1 to 40 carbon atoms.

2. The ethylene polymer composition according to claim 1, wherein The variant spherulites have one or more of the following characteristics: (1) The overall morphology of the variant spherulites is spherical or quasi-spherical; (2) The maximum diameter of the mutant spherulites is 20 μm to 500 μm; (3) The central bright area is composed of one or more needle-shaped units, narrow dumbbell-shaped units or bundle-shaped units; (4) The central bright area is radial in shape as a whole; (5) The shape of the dark area includes one or more of a double semicircle, an oval, a circle, a jujube-shaped circle, and an oblate circle; (6) The area of the extinction dark zone accounts for 50% to 95% of the total area of the mutant spherulites.

3. The ethylene polymer composition according to claim 1, wherein The mass ratio of the ethylene polymer to the composite organic improver is 100:0.01-10, and the mass ratio of the compound A to the compound B is 1-1000:1-1000.

4. The ethylene polymer composition according to claim 3, wherein The mass ratio of the compound A to the compound B is 1-100:1-100.

5. The ethylene polymer composition according to any one of claims 1 to 4, characterized in that The composite organic improver has one or more of the following characteristics: (1) The difference ΔW between the peak positions of the characteristic absorption peaks of the NH bending and CN stretching coupling vibrations between the compound A and the compound B in the infrared spectrum within the range of 1600 to 1400 wavenumbers does not exceed 15 wavenumbers; (2) The composite organic improver has a characteristic absorption peak of NH stretching vibration in the wave number range of 3500-3100 in the infrared spectrum, and a characteristic absorption peak of carbonyl stretching vibration in the wave number range of 1700-1600; (3) The melting point range of the composite organic improver is 100°C to 370°C; (4) the composite organic improver is heated from 25° C. to a molten state and then cooled to 25° C. to form a fibrous structure; (5) The composite organic improver is characterized by two-stage thermal weight loss in the first-stage thermal weight loss temperature range of 100°C to 300°C and the second-stage thermal weight loss temperature range of 200°C to 450°C under thermogravimetric analysis, or multiple-stage thermal weight loss in the weight loss temperature range of 100°C to 450°C.

6. The ethylene polymer composition according to claim 5, wherein In the characteristic (1) of the composite organic improver, the difference ΔW between the peak positions of the characteristic absorption peaks of NH bending and CN stretching coupling vibrations existing in the infrared spectrum range of 1600 to 1400 wavenumbers between the compound A and the compound B does not exceed 10 wavenumbers; And / or, in the feature (3) of the composite organic improver, the melting point of the composite organic improver is in the range of 200°C to 320°C.

7. The ethylene polymer composition according to claim 6, wherein In the characteristic (1) of the composite organic improver, the difference ΔW between the peak positions of the characteristic absorption peaks of the NH bending and CN stretching coupling vibrations existing in the infrared spectrum range of 1600 to 1400 wavenumbers between the compound A and the compound B does not exceed 5 wavenumbers; And / or, in the feature (3) of the composite organic improver, the melting point of the composite organic improver is in the range of 250°C to 300°C.

8. The ethylene polymer composition according to any one of claims 1 to 4, characterized in that The ethylene polymer includes one or more of an ethylene homopolymer and an ethylene copolymer. The ethylene copolymer is a copolymer of ethylene and a C3-C10 α-olefin monomer.

9. The ethylene polymer composition according to any one of claims 1 to 4, characterized in that R1, R2, R3, and R5 are independently selected from one or more of methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, phenyl, benzyl, 4-methylbenzyl, 2-methylallyl, cyclohexyl, cyclohexylmethyl, 1-cyclohexylethyl, and 2-cyclohexylethyl; The R4 is selected from one or more of ethanediyl, propanediyl, butanediyl, pentanediyl, 2,2-dimethylpropane-1,3-diyl, hexanediyl, heptanediyl, octanediyl, decanediyl, dodecanediyl, cyclohexanediyl, methylbenzenediyl, dimethylbenzenediyl, benzenediyl, naphthalenediyl, biphenyldiyl, dimethylbiphenyl, diphenylmethanediyl, (1-methylethylidene)biphenyl-4,4'-diyl and 1,3,3-trimethylcyclohexylmethyl-5-yl.

10. A method for preparing an ethylene polymer composition according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, mixing the ethylene polymer and the composite organic improving agent to obtain a mixed material; S2. Melt-blending the mixture at a temperature of 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling the mixture so that compound A and compound B in the composite organic improver induce the molecular chains of the ethylene polymer to form the variant spherulites through self-assembly heterogeneous nucleation, thereby obtaining an ethylene polymer composition.

11. A method for preparing an ethylene polymer composition according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, dividing the ethylene polymer into N parts, 2≤N≤9, and uniformly mixing the first part of the ethylene polymer with the composite organic improver to obtain a first mixed material; S2, melt blending the first mixed material at a temperature 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling to obtain a first granular masterbatch; S3, uniformly mixing the second portion of the ethylene polymer with the first portion of the granular masterbatch to obtain a second mixed material; S4, repeating the process of step S2 and step S3 until the Nth part of the ethylene polymer and the N-1th part of the granular masterbatch are uniformly mixed to obtain the Nth part of the mixed material; S5. Melt-blending the Nth portion of the mixed material at a temperature 20° C. to 150° C. above the melting point of the ethylene polymer, and then cooling the mixture to obtain an ethylene polymer composition having a crystal morphology of modified spherulites.

12. The method for preparing an ethylene polymer composition according to claim 10 or 11, wherein: The preparation method has one or more of the following characteristics: (1) The cooling is performed at a cooling rate of 10°C / min to 100°C / min to a temperature of 0°C to 40°C; (2) The melt blending time is 1 min to 10 min.

13. Use of the ethylene polymer composition according to any one of claims 1 to 9 or the ethylene polymer composition prepared by the preparation method according to any one of claims 10 to 12 in blow molded products, cast molded products, injection molded products, extrusion molded products, compression molded products, vacuum molded products, rotational molded products, and blister molded products.

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