Continuous fiber reinforced polyglycolic acid thermally conductive composite material, preparation method and application thereof

Abstract

The present application relates to the technical field of high polymer composite material, and provides a continuous fiber reinforced polyglycolic acid heat conducting composite material, a preparation method and application thereof.The continuous fiber reinforced polyglycolic acid heat conducting composite material comprises a core material and at least one layer of outer material; the core material comprises a first polyglycolic acid resin, glass fiber and a first additive, the glass fiber continuously extends from one end of the core material to the opposite end; the outer material wraps the core material, and the outer material comprises a second polyglycolic acid resin, a heat conducting filler and a second additive.The continuous fiber reinforced polyglycolic acid heat conducting composite material is designed based on a multi-component and multi-module system, can greatly improve the proportion of the heat conducting filler in the polyglycolic acid, uniformly disperse the heat conducting filler, fully play the synergistic effect between the fillers, enhance the mechanical properties and heat conducting properties of the composite material, and meet the application in the heat conducting material field.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer composites, more particularly, to a continuous fiber reinforced polyglycolic acid heat conductive composite material, a preparation method and application thereof. BACKGROUND

[0002] As an environmentally friendly biodegradable material, polyglycolic acid (PGA) has a simple and regular linear molecular structure and is a biodegradable polymer material that has been widely studied in recent years. Unlike traditional polymers such as polyethylene and polypropylene, PGA gradually degrades under certain conditions and changes into carbon dioxide and water, which are harmless to the human body and the environment. This is of great significance to solving the current white pollution and implementing the "double carbon" policy.

[0003] Compared with other biodegradable polymers such as polylactic acid (PLA), PGA has one less carbon in the repeating unit of the molecular chain, but it has good barrier properties, with a water vapor barrier that is 100 times higher than that of polylactic acid and is not affected by environmental temperature. In addition, the mechanical properties (tensile strength, bending modulus) and heat resistance of PGA are also higher than those of polylactic acid. Therefore, PGA can be used as a substitute for traditional high-strength engineering plastics, especially in the emerging fields of 5G, photovoltaic, LED lighting, mobile phones, etc., and can replace engineering plastics such as nylon 6 as controllable degradable heat conductive materials. It can also be widely used in packaging, medical, oil and gas fields, such as disposable heat conductive materials for hot compress products in the fields of medical beauty and health. Currently, many companies have laid out PGA production, and with the improvement of subsequent technology and production capacity, PGA will usher in large-scale promotion.

[0004] Although PGA has excellent mechanical and gas barrier properties, due to its high regularity of the molecular chain, the molecular chains interact strongly, and the melting point is relatively high, which makes the melting temperature and decomposition temperature close, the melt strength low, and the processing difficult, thus limiting its application.

[0005] Existing technologies usually use chain extenders and inorganic fillers to modify PGA to enhance its melt strength and improve its processing performance. Chen Lanlan et al. (Plastics Industry, 2021, 49(02), 145-149) modified PGA by melt modification with an epoxy chain extender, which increased the initial decomposition temperature of PGA by 22℃ and the melt viscosity by more than 6 times. Chinese patents CN112469765A and CN104684997B both propose preparing a polyglycolic acid composition by extruding and granulating PGA with inorganic fillers to improve the melt thermal stability and tensile modulus of the material.

[0006] Compared with the above modification method, continuous fiber reinforced thermoplastic composite material is a common thermoplastic composite material, which can make the composite material have excellent mechanical properties, is one of the fastest growing materials in the current composite material market and has other characteristics. Especially for the current use in emerging 5G, photovoltaic, LED lighting, mobile phone and other fields, continuous glass fiber reinforced thermal conductive composite materials have also received high attention. In addition, the fiber itself belongs to the category of degradable materials, and has broad application prospects in degradable material modification. However, the preparation of degradable composite materials by using continuous fiber reinforced degradable resin materials has the technical difficulty of filler-matrix dispersion difficulty due to the high inorganic filling ratio, especially in the field of thermal conductivity. At the same time, the fiber is blended and added with a large amount of thermal conductive filler, and the problems of aggregation and bridging are prone to occur among the multiphase fillers, which has adverse effects on the formability, thermal conductivity and mechanical properties of the material.

[0007] For the above problems, the existing technology cannot meet the actual demand. Therefore, it has important market value and research significance to develop a new polyglycolic acid thermal conductive composite material with uniform filler dispersion, high filling amount and good formability, thermal conductivity and mechanical properties, as well as its production process and application. SUMMARY

[0008] To solve the above technical problems, the present application provides a continuous fiber reinforced polyglycolic acid thermal conductive composite material and its preparation method and application.

[0009] The technical scheme adopted by the present application is:

[0010] In a first aspect, the present application provides a continuous fiber reinforced polyglycolic acid thermal conductive composite material, which comprises an inner core material and at least one outer layer material; the inner core material comprises a first polyglycolic acid resin, glass fiber and a first auxiliary agent, the glass fiber continuously extends from one end of the inner core material to the opposite end; the outer layer material wraps the inner core material, and the outer layer material comprises a second polyglycolic acid resin, a thermal conductive filler and a second auxiliary agent.

[0011] As a preferred scheme of the composite material provided by the present application, in the inner core material, the amount of first polyglycolic acid resin is 100 parts by weight, and the amount of glass fiber is 10-200 parts by weight, preferably 10-150 parts by weight, and more preferably 20-150 parts by weight;

[0012] And / or, in the outer layer material, the amount of second polyglycolic acid resin is 100 parts by weight, and the amount of thermal conductive filler is 1-200 parts by weight, preferably 10-180 parts by weight, and more preferably 20-150 parts by weight;

[0013] and / or, in the composite material, the first polyglycolic acid resin is used in an amount of 1-100 parts by weight, preferably 10-100 parts by weight, more preferably 50-100 parts by weight, based on 100 parts by weight of the second polyglycolic acid resin.

[0014] As another preferred embodiment of the composite material provided by the present application, the thermally conductive filler comprises a thermally conductive main material and a thermally conductive auxiliary material, the thermally conductive main material is selected from metal oxides and / or metal hydroxides, and the thermally conductive auxiliary material is selected from inorganic powders.

[0015] Preferably, the content of the thermally conductive main material is 50-98 wt%, and the content of the thermally conductive auxiliary material is 2-50 wt%, based on the total weight of the thermally conductive filler.

[0016] As another preferred embodiment of the composite material provided by the present application, the thermally conductive main material is selected from at least one of aluminum oxide, antimony trioxide, titanium dioxide, magnesium oxide, aluminum hydroxide, and magnesium hydroxide, preferably at least one of aluminum oxide, magnesium oxide, aluminum hydroxide, and magnesium hydroxide.

[0017] and / or, the particle size of the thermally conductive main material is 1-100 μm, preferably 1-40 μm;

[0018] and / or, the inorganic powder is selected from at least one of carbon nanotubes, carbon black, flaky graphite, graphene, boron nitride, boron carbide, aluminum nitride, and silicon carbide, preferably at least one of boron nitride, aluminum nitride, and silicon carbide.

[0019] and / or, the particle size of the inorganic powder is 1-100 μm, preferably 1-50 μm.

[0020] As another preferred embodiment of the composite material provided by the present application, the first polyglycolic acid resin and the second polyglycolic acid resin are the same or different, and each is independently selected from homopolymer polyglycolic acid and / or copolymer polyglycolic acid; preferably, the content of glycolic acid monomer in the copolymer polyglycolic acid is ≥90 mol%, preferably ≥95 mol%;

[0021] and / or, the melt flow rate of the first polyglycolic acid resin at 230°C under a load of 2.16 kg is 5-500 g / 10 min, preferably 10-200 g / 10 min, more preferably 10-100 g / 10 min;

[0022] and / or, the melt flow rate of the second polyglycolic acid resin at 230°C under a load of 2.16 kg is 5-500 g / 10 min, preferably 10-200 g / 10 min, more preferably 10-100 g / 10 min.

[0023] As another preferred scheme of the composite material provided by the present application, the first polyglycolic acid resin is used in an amount of 100 parts by weight, and the first auxiliary agent comprises at least one of 0.05-5 parts by weight of a first compatibilizer, 0.1-3 parts by weight of a first antioxidant, and 0.1-1 part by weight of a first lubricant; preferably, the first polyglycolic acid resin is used in an amount of 100 parts by weight, and the first auxiliary agent comprises at least one of 0.05-2 parts by weight of a first compatibilizer, 0.1-1 part by weight of a first antioxidant, and 0.2-1 part by weight of a first lubricant;

[0024] and / or, the second polyglycolic acid resin is used in an amount of 100 parts by weight, and the second auxiliary agent comprises at least one of 0.05-5 parts by weight of a second compatibilizer, 0.1-3 parts by weight of a second antioxidant, and 0.1-1 part by weight of a second lubricant; preferably, the second polyglycolic acid resin is used in an amount of 100 parts by weight, and the second auxiliary agent comprises at least one of 0.05-2 parts by weight of a second compatibilizer, 0.1-1 part by weight of a second antioxidant, and 0.2-1 part by weight of a second lubricant.

[0025] As another preferred scheme of the composite material provided by the present application, the first compatibilizer and the second compatibilizer are the same or different, and each is independently selected from at least one of a coupling agent, preferably at least one of a silane coupling agent, a titanate coupling agent, an organic chromium complex coupling agent, more preferably a silane coupling agent;

[0026] and / or, the first antioxidant and the second antioxidant are the same or different, and each is independently selected from at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 2246, antioxidant CA, and antioxidant 626, preferably at least one of antioxidant 1010, antioxidant 168;

[0027] and / or, the first lubricant and the second lubricant are the same or different, and each is independently selected from at least one of ethylene bis-stearamide, calcium stearate, monoglyceride fatty acid, polyethylene wax, erucamide, pentaerythritol stearate.

[0028] As another preferred scheme of the composite material provided by the present application, the inner core material does not contain non-oriented short fibers, and preferably, the inner core material is composed of the first polyglycolic acid resin, glass fibers, and the first auxiliary agent.

[0029] In a second aspect, the present application provides a preparation method of the continuous fiber-reinforced polyglycolic acid heat-conducting composite material described above, comprising:

[0030] S1. mixing the first polyglycolic acid resin and the first auxiliary agent and then melting to obtain a first component melt;

[0031] S2. performing a first impregnation treatment on the continuous glass fiber with the first component melt in step S1 to form a filamentous inner core material;

[0032] S3. mixing and melting the second polyglycolic acid resin, the heat conductive filler and the second auxiliary agent to obtain a second component melt;

[0033] S4. performing at least one second impregnation treatment on the inner core material obtained in step S2 with at least one second component melt obtained in step S3 to obtain a continuous glass fiber reinforced polyglycolic acid heat conductive composite material.

[0034] As a preferred embodiment of the preparation method provided by the present application, the mixing condition in step S1 is that the temperature is 40-60℃ and the time is 3-5min; and / or the melting temperature in step S1 is 230-260℃.

[0035] As another preferred embodiment of the preparation method provided by the present application, the mixing condition in step S3 is that the temperature is 40-60℃ and the time is 3-5min; and / or the melting temperature in step S3 is 230-260℃.

[0036] As another preferred embodiment of the preparation method provided by the present application, step S2 further comprises: performing a dispersion treatment and a preheating treatment on the continuous glass fiber before performing the first impregnation treatment on the continuous glass fiber; preferably, the temperature of the preheating treatment is 80-250℃.

[0037] As another preferred embodiment of the preparation method provided by the present application, step S4 further comprises: after the second impregnation treatment, performing a pulling-out, a stretching, a cooling, a drying and a cutting treatment on the material obtained after the second impregnation treatment to obtain the continuous glass fiber reinforced polyglycolic acid heat conductive composite material.

[0038] As another preferred embodiment of the preparation method provided by the present application, the first impregnation treatment in step S2 is performed in a first impregnation mold, the first impregnation mold is an adjustable impregnation mold, the first impregnation mold comprises a fiber inlet, a fiber outlet and a melt flow channel, at least one first godet is arranged in the mold cavity of the first impregnation mold; the first godet can move between the fiber inlet and the fiber outlet; and / or the first godet can move in a direction perpendicular to the connecting line of the fiber inlet and the fiber outlet.

[0039] As another preferred scheme of the preparation method provided by the present application, the first impregnation treatment in step S2 is performed in a second impregnation mold, the second impregnation mold is a combined impregnation mold, the second impregnation mold comprises a first module, an intermediate module and a second module connected in sequence, the first module is provided with a fiber inlet and a first module flow channel, the second module is provided with a fiber outlet and a second module flow channel, and the intermediate module is provided with an intermediate module flow channel; after the first module, the intermediate module and the second module are connected in sequence, the first module flow channel, the intermediate module flow channel and the second module flow channel are communicated to form a combined flow channel for the fiber to pass through.

[0040] As another preferred scheme of the preparation method provided by the present application, the first impregnation treatment in step S2 is performed in a third impregnation mold, the third impregnation mold is a strong turbulent flow impregnation mold, the third impregnation mold comprises a fiber inlet channel, an impregnation outlet and a melt slit flow channel, and the fiber inlet channel, the impregnation outlet and the melt slit flow channel are all communicated with a mold cavity in the third impregnation mold; wherein a second godet is arranged in the mold cavity of the third impregnation mold, and the second godet comprises at least one driving godet, and the driving godet is driven to rotate by a driving device.

[0041] In a third aspect, the present application provides applications of the above-mentioned continuous fiber reinforced polyglycolic acid thermal conductive composite material or the continuous fiber reinforced polyglycolic acid thermal conductive composite material prepared by the above-mentioned preparation method in the field of disposable thermal conductive materials, the field of controllable degradable thermal conductive materials, and / or the field of medical cosmetology, electrical components, oil field chemical industry and engineering plastics.

[0042] The present application has at least the following beneficial effects:

[0043] (1) The continuous fiber reinforced polyglycolic acid thermal conductive composite material of the present application has an inner-outer layer composite structure. The continuous / constant-length glass fibers contained in the inner layer material are subjected to impregnation treatment, which not only realizes the uniform dispersion of high-content long fibers in polyglycolic acid, but also prevents fiber leakage, fully plays the role of long fibers in increasing rigidity and improving heat resistance, etc. The addition of thermal conductive fillers in the outer layer material can improve the processing fluidity of polyglycolic acid, increase its melt strength, and effectively enhance the processing fluidity, thermal conductivity and mechanical strength of polyglycolic acid, while also greatly reducing the cost of the composite material.

[0044] (2) The continuous fiber reinforced polyglycolic acid heat conductive composite material of the present application uses high filling amount of continuous / glass fiber to modify polyglycolic acid in cooperation with heat conductive fillers through inner and outer layer composite structure, effectively solves the technical difficulty of filler-substrate dispersion difficulty caused by high inorganic filling ratio in the existing continuous fiber reinforced composite material, avoids the problems of aggregation and bridging caused by simultaneous blending of glass fiber and a large amount of heat conductive fillers, so that the prepared continuous fiber reinforced polyglycolic acid heat conductive composite material not only has excellent biodegradability, but also has short molding cycle and high mechanical strength, which can expand the application range and market value of polyglycolic acid composite material. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 It is a structure schematic view of the continuous fiber reinforced polyglycolic acid heat conductive composite material in an embodiment of the present application.

[0046] Figure 2 It is a structure schematic view of the continuous fiber reinforced polyglycolic acid heat conductive composite material manufacturing system in an embodiment of the present application.

[0047] Figure 3 It is a structure schematic view of the continuous fiber reinforced polyglycolic acid heat conductive composite material manufacturing system in another embodiment of the present application.

[0048] Figure 4 It is a sectional view of the first impregnation mold in an embodiment of the present application.

[0049] Figure 5 It is a sectional view of the second impregnation mold in an embodiment of the present application.

[0050] Figure 6 It is a sectional view of the third impregnation mold in an embodiment of the present application.

[0051] Figure 7 It is a schematic view of the second impregnation treatment in an embodiment of the present application.

[0052] Figure 8 It is a sectional view of the molding mold used in the second impregnation treatment in an embodiment of the present application.

[0053] Explanation of reference signs:

[0054] 0-1, core material; 0-2, fiber bundle; 0-3, outer layer material;

[0055] 1, fiber frame and fiber guiding device; 2, fiber pretreatment device; 3, first impregnation mold; 4, molten plasticizing feeding device; 5, molding mold; 6, cooling water tank; 7, drying machine; 8, traction machine; 9, granulator; 10, collection box;

[0056] A300, first impregnation die head; A1, fiber inlet; A2, second runner; A3, melt channel; A4, first runner; A5, upper die cover; A6, fiber outlet; A7, impregnation die body; A8, first godet;

[0057] B300, second impregnation die head; B1, fiber inlet; B2, melt channel; B3, first module; B31, first module channel; B4, combined channel; B5, standardization joint; B6, intermediate module; B61, intermediate module channel; B7, second module; B71, second module channel; B8, fiber outlet;

[0058] C300, third impregnation die head; C1, melt split channel; C2, impregnation die outer body; C3, fiber inlet channel; C4, driving godet; C5, driven godet; C6, impregnation outlet;

[0059] 4-1, extruder I; 4-2, extruder II;

[0060] 5-1, core; 5-2, sheath; 5-3, sheath die plate; 5-4, strand; 5-5, second resin inlet. DETAILED DESCRIPTION

[0061] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly, the present application will be further described in detail below in combination with specific embodiments. It should be understood that the specific embodiments described herein are only used to specifically illustrate the present patent and do not limit the protection scope of the present application in any way.

[0062] In a first aspect, the present application provides a continuous fiber reinforced polyglycolic acid heat conducting composite material, comprising an inner core material and at least one outer layer material; the inner core material comprises a first polyglycolic acid resin, glass fibers and a first additive, the glass fibers continuously extend from one end of the inner core material to the opposite end; the outer layer material wraps the inner core material, and the outer layer material comprises a second polyglycolic acid resin, a heat conducting filler and a second additive.

[0063] The present inventors have found that by impregnating continuous glass fibers with a first component comprising a first polyglycolic acid resin and a first additive to form an inner core material, and uniformly coating a second component comprising a second polyglycolic acid resin, a heat conducting filler and a second additive on the outer side of the inner core material, a continuous fiber reinforced polyglycolic acid heat conducting composite material is formed, which has an inner core material of continuous glass reinforced resin and an outer layer material of resin layer wrapped on the outer side of the inner core material. Such a polyglycolic acid composite material has good mechanical properties and heat conducting properties.

[0064] In the present application, the terms "one end" and "opposite end" are generally relative to the longitudinal direction of the continuous fiber-reinforced polyglycolic acid thermally conductive composite material.

[0065] In the cross-section of the continuous fiber-reinforced polyglycolic acid thermally conductive composite material in the transverse direction, the inner core material and the outer layer material are sequentially arranged from the inside to the outside, and the glass fibers are oriented along the longitudinal direction of the continuous fiber-reinforced polyglycolic acid thermally conductive composite material in the inner core material.

[0066] In the present application, the glass fibers are glass fiber bundles, and the length of the glass fiber bundles is substantially the same as the length (longitudinal dimension) of the continuous fiber-reinforced polyglycolic acid thermally conductive composite material, so that the glass fiber bundles continuously extend from one end to the opposite end of the longitudinal direction of the inner core material. The inner core material does not contain short fibers, especially non-oriented short fibers.

[0067] In the continuous fiber-reinforced polyglycolic acid thermally conductive composite material of the present application, the outer layer material at least 80% covers the inner core material, for example, 80-99%, 85-95% covers the inner core material; the outer layer material can also continuously cover the inner core material.

[0068] The outer layer material is not limited to the number of layers, and can be one layer or multiple layers. In some embodiments, the multiple layers of the outer layer material can be formed of the same material or multiple materials.

[0069] The glass fibers are continuous and / or fixed-length glass fibers.

[0070] According to some embodiments of the present application, the composite material is in the form of a strip, a rod or a particle.

[0071] In the present application, the strip, rod or particle-shaped continuous fiber-reinforced polyglycolic acid thermally conductive composite material can be cut from a continuous filament-shaped continuous fiber-reinforced polyglycolic acid thermally conductive composite material.

[0072] Further preferably, the length of the strip or rod-shaped composite material is 6-25 mm, for example, it can be 6 mm, 8 mm, 10 mm, 12 mm, 15 mm, 20 mm, 22 mm, 25 mm, etc., preferably 8-20 mm, more preferably 10-15 mm; and / or the particle size of the particle-shaped composite material is 3-5 mm, for example, it can be 3 mm, 4 mm, 5 mm, etc., preferably 3-4 mm.

[0073] The present application does not have special requirements for the cross-sectional shape of the continuous fiber-reinforced polyglycolic acid thermally conductive composite material. In some embodiments, the cross-section of the particle or rod-shaped continuous fiber-reinforced polyglycolic acid thermally conductive composite material is circular or circular-like. In other embodiments, the cross-section of the particle or strip-shaped continuous fiber-reinforced polyglycolic acid thermally conductive composite material is rectangular or square.

[0074] According to some embodiments of the present application, in the inner core material, the first polyglycolic acid resin is used in an amount of 10-200 parts by weight, for example, 10 parts by weight, 20 parts by weight, 30 parts by weight, 50 parts by weight, 60 parts by weight, 80 parts by weight, 100 parts by weight, 120 parts by weight, 150 parts by weight, 180 parts by weight, 200 parts by weight, etc., preferably 10-150 parts by weight, more preferably 20-150 parts by weight.

[0075] According to some embodiments of the present application, in the outer layer material, the second polyglycolic acid resin is used in an amount of 1-200 parts by weight, for example, 1 part by weight, 10 parts by weight, 20 parts by weight, 30 parts by weight, 50 parts by weight, 80 parts by weight, 100 parts by weight, 130 parts by weight, 132 parts by weight, 135 parts by weight, 140 parts by weight, 150 parts by weight, 160 parts by weight, 180 parts by weight, 200 parts by weight, etc. In some preferred embodiments, the second polyglycolic acid resin is used in an amount of 10-180 parts by weight, preferably 20-150 parts by weight.

[0076] According to some embodiments of the present application, in the composite material, the first polyglycolic acid resin is used in an amount of 100 parts by weight, and the second polyglycolic acid resin is used in an amount of 1-100 parts by weight, for example, 1 part by weight, 10 parts by weight, 30 parts by weight, 50 parts by weight, 60 parts by weight, 80 parts by weight, 100 parts by weight, etc., preferably 10-100 parts by weight, more preferably 50-100 parts by weight.

[0077] According to some embodiments of the present application, the thermally conductive filler comprises a thermally conductive main material and a thermally conductive auxiliary material, the thermally conductive main material is selected from metal oxides and / or metal hydroxides, and / or the thermally conductive auxiliary material is selected from inorganic powders.

[0078] According to some embodiments of the present application, the content of the thermally conductive main material is 50-98 wt%, and the content of the thermally conductive auxiliary material is 2-50 wt%, based on the total weight of the thermally conductive filler.

[0079] According to some embodiments of the present application, the weight ratio of the thermally conductive main material to the thermally conductive auxiliary material is (4-10):(1-3). For example, the weight ratio of the thermally conductive main material to the thermally conductive auxiliary material can be 4:1, 4:3, 5:1, 5:3, 7:2, 8:1, 10:1, 10:3, etc.

[0080] According to some embodiments of the present application, the thermally conductive main material is selected from at least one of aluminum oxide, antimony trioxide, titanium dioxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide, preferably at least one of aluminum oxide, magnesium oxide, aluminum hydroxide, magnesium hydroxide.

[0081] According to some embodiments of the present application, the particle size of the heat-conducting main material is 1-100 μm, for example, 1 μm, 2 μm, 4 μm, 5 μm, 10 μm, 20 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, etc. Preferably, 1-40 μm. In some embodiments, the heat-conducting main material comprises a first heat-conducting main material and an optional second heat-conducting main material, the particle size of the first heat-conducting main material is 1-10 μm, the particle size of the second heat-conducting main material is 20-40 μm, and the weight ratio of the first heat-conducting main material to the second heat-conducting main material is 2:1-1:0, for example, 2:1-1:2.

[0082] According to some embodiments of the present application, the inorganic powder is selected from at least one of carbon nanotubes, carbon black, flake graphite, graphene, boron nitride, boron carbide, aluminum nitride, silicon carbide, preferably at least one of boron nitride, aluminum nitride, silicon carbide.

[0083] According to some embodiments of the present application, the particle size of the inorganic powder is 1-100 μm, for example, 1 μm, 2 μm, 4 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, etc., preferably 1-50 μm, more preferably 1-20 μm.

[0084] According to some embodiments of the present application, the first polyglycolic acid resin and the second polyglycolic acid resin are the same or different, and are independently selected from homopolymer polyglycolic acid and / or copolymer polyglycolic acid; preferably, the content of glycolic acid monomer in the copolymer polyglycolic acid is ≥90 mol%, preferably ≥95 mol%.

[0085] In different embodiments of the present application, the melt flow rate of the first polyglycolic acid resin and the second polyglycolic acid resin is not particularly limited, and can be selected according to the desired performance of the composite material.

[0086] In particular, the present inventors have found that the parameters (for example, melt flow rate) according to the present application can be used to prepare polyglycolic acid composite materials with high surface quality performance and comprehensive performance. For example, the melt flow rate of the first polyglycolic acid resin is higher than that of the second polyglycolic acid resin, so that the polyglycolic acid composite material has improved mechanical properties; on the contrary, the melt flow rate of the second polyglycolic acid resin is higher than that of the first polyglycolic acid resin, so that the polyglycolic acid composite material has improved gloss.

[0087] According to some embodiments of the present application, the first polyglycolic acid resin has a melt flow rate of 5-500 g / 10 min under the condition of 230°C, 2.16 kg, for example, it can be 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 40 g / 10 min, 50 g / 10 min, 80 g / 10 min, 100 g / 10 min, 150 g / 10 min, 200 g / 10 min, 300 g / 10 min, 400 g / 10 min, 500 g / 10 min, etc. Preferably, it is 10-200 g / 10 min, more preferably, it is 10-100 g / 10 min.

[0088] According to some embodiments of the present application, the second polyglycolic acid resin has a melt flow rate of 5-500 g / 10 min under the condition of 230°C, 2.16 kg, for example, it can be 5 g / 10 min, 10 g / 10 min, 20 g / 10 min, 40 g / 10 min, 50 g / 10 min, 80 g / 10 min, 100 g / 10 min, 150 g / 10 min, 200 g / 10 min, 300 g / 10 min, 400 g / 10 min, 500 g / 10 min, etc. Preferably, it is 10-200 g / 10 min, more preferably, it is 10-100 g / 10 min.

[0089] The specific types and amounts of various additives in the first additive and the second additive are not limited in the present application, which aims to achieve the relevant performance of the composite material and the role of the relevant additives.

[0090] According to some embodiments of the present application, the total amount of the first polyglycolic acid resin is 100 parts by weight, and the first additive includes at least one of 0.05-5 parts by weight of the first compatibilizer, 0.1-3 parts by weight of the first antioxidant, and 0.1-1 part by weight of the first lubricant. For example, the amount of the first compatibilizer can be 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 parts by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, etc.; and / or the amount of the first antioxidant can be 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 1 parts by weight, 2 parts by weight, 3 parts by weight, etc.; and / or the amount of the first lubricant can be 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 parts by weight, etc.

[0091] Preferably, the amount of the first polyglycolic acid resin is 100 parts by weight, and the first additive includes at least one of 0.05-2 parts by weight of the first compatibilizer, 0.1-1 parts by weight of the first antioxidant, and 0.2-1 part by weight of the first lubricant.

[0092] According to some embodiments of the present application, the second polyglycolic acid resin is used in an amount of 100 parts by weight, and the second auxiliary agent includes at least one of 0.05-5 parts by weight of a second compatibilizer, 0.1-3 parts by weight of a second antioxidant, and 0.1-1 parts by weight of a second lubricant. For example, the second compatibilizer can be used in an amount of 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 parts by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, etc.; and / or, the second antioxidant can be used in an amount of 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 1 parts by weight, 2 parts by weight, 3 parts by weight, etc.; and / or, the second lubricant can be used in an amount of 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 parts by weight, etc.

[0093] Preferably, the second polyglycolic acid resin is used in an amount of 100 parts by weight, and the second auxiliary agent includes at least one of 0.05-2 parts by weight of a second compatibilizer, 0.1-1 parts by weight of a second antioxidant, and 0.2-1 parts by weight of a second lubricant.

[0094] According to some embodiments of the present application, the first compatibilizer and the second compatibilizer are the same or different, and each is independently selected from at least one of a coupling agent, preferably at least one of a silane coupling agent, a titanate coupling agent, an organic chromium complex coupling agent, more preferably a silane coupling agent. Examples of silane coupling agents suitable for use in the present application include, but are not limited to, KH-550, KH-560.

[0095] According to some embodiments of the present application, the first antioxidant and the second antioxidant are the same or different, and each is independently selected from at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 2246, antioxidant CA, and antioxidant 626, preferably at least one of antioxidant 1010, antioxidant 168.

[0096] According to some embodiments of the present application, the first lubricant and the second lubricant are the same or different, and each is independently selected from at least one of ethylene bis-stearamide, calcium stearate, monoglyceride fatty acid, polyethylene wax, erucamide, pentaerythritol stearate.

[0097] In different embodiments of the present application, the first auxiliary agent and the second auxiliary agent are not limited to the specific types and amounts of the several auxiliary agents, and each can have a relatively wide selection range. For example, the first auxiliary agent and the second auxiliary agent each independently can further include at least one of a chain extender, a slip agent, an antistatic agent, and a plasticizer.

[0098] In a second aspect, the present application provides a method for preparing a continuous fiber-reinforced polyglycolic acid thermally conductive composite material, comprising:

[0099] S1. mixing and melting the first polyglycolic acid resin and the first auxiliary agent to obtain a first component melt;

[0100] S2. performing a first impregnation treatment on the continuous glass fiber with the first component melt in step S1 to form a filamentous inner core material;

[0101] S3. mixing and melting the second polyglycolic acid resin, the thermally conductive filler and the second auxiliary agent to obtain a second component melt;

[0102] S4. performing at least one second impregnation treatment on the inner core material obtained in step S2 with at least one second component melt obtained in step S3 to obtain a continuous glass fiber reinforced polyglycolic acid thermally conductive composite material.

[0103] The preparation method of the present application can be performed continuously in line to obtain a continuous filamentous product, which can be directly stored and used, or cut into a strip, rod or granular product with a certain length or particle size.

[0104] According to some embodiments of the present application, the mixing conditions in step S1 are: a temperature of 40-60℃ and a time of 3-5min; and / or the melting temperature in step S1 is 230-260℃.

[0105] According to some embodiments of the present application, the mixing conditions in step S3 are: a temperature of 40-60℃ and a time of 3-5min; and / or the melting temperature in step S3 is 230-260℃.

[0106] In the present application, the melting time in step S1 and step S3 can have a wide selection range, in order to enable the first polyglycolic acid resin and the first auxiliary agent, and the second polyglycolic acid resin, the thermally conductive filler and the second auxiliary agent to be fully melted to obtain a melt.

[0107] According to some embodiments of the present application, the step S2 further comprises: performing a dispersion treatment and a preheating treatment on the continuous glass fiber before performing the first impregnation treatment. Preferably, the preheating treatment is performed at a temperature of 80-250℃. The dispersion treatment process in the present application adopts a conventional fiber dispersion treatment process in the art.

[0108] According to some embodiments of the present application, the step S4 further comprises: after the second impregnation treatment, performing a pulling-out, stretching, cooling, drying and granulating treatment on the material obtained after the second impregnation treatment to obtain a continuous glass fiber reinforced polyglycolic acid thermally conductive composite material. In the present application, the process conditions of the pulling-out, stretching, cooling, drying and granulating treatment are not particularly limited, and a person skilled in the art can adjust them according to the specific performance requirements of the prepared continuous fiber reinforced polyglycolic acid thermally conductive composite material.

[0109] According to some embodiments of the present application, the first impregnation process in step S2 can be performed in a first impregnation die, which is an adjustable impregnation die, the first impregnation die comprising a fiber inlet, a fiber outlet and a melt runner, at least one first godet being arranged in a die cavity of the first impregnation die; the first godet being movable between the fiber inlet and the fiber outlet; and / or, the first godet being movable in a direction perpendicular to a line connecting the fiber inlet and the fiber outlet.

[0110] According to some embodiments of the present application, the first impregnation process in step S2 can be performed in a second impregnation die, which is a combined impregnation die, the second impregnation die comprising a first module, an intermediate module and a second module connected in sequence, the first module being provided with a fiber inlet and a first module runner, the second module being provided with a fiber outlet and a second module runner, the intermediate module being provided with an intermediate module runner; after the first module, the intermediate module and the second module are connected in sequence, the first module runner, the intermediate module runner and the second module runner are connected in communication to form a combined runner for the fibers to pass through.

[0111] According to some embodiments of the present application, the first impregnation process in step S2 can also be performed in a third impregnation die, which is a strong turbulent impregnation die, the third impregnation die comprising a fiber inlet channel, an impregnation outlet and a melt slit runner, the fiber inlet channel, the impregnation outlet and the melt slit runner all being connected to a die cavity inside the third impregnation die; wherein the die cavity of the third impregnation die is provided with a second godet, the second godet comprising at least one driven godet, the driven godet being driven to rotate by a driving device.

[0112] The first impregnation die, the second impregnation die and the third impregnation die used in the present application are described in Chinese patent applications CN202011193483.3, 202011191450.5 and 202011199839.4, which are incorporated herein by reference in their entirety.

[0113] It should be noted that the first impregnation die, the second impregnation die and the third impregnation die described above can be applied to any existing manufacturing system and preparation technology of continuous fiber reinforced polyglycolic acid heat conducting composite materials.

[0114] According to some embodiments of the preparation method of the present application, the second impregnation treatment in step S4 can be performed in a forming mold. The forming mold is composed of a core, an outer sleeve, and an outer sleeve die plate. The core is located inside the outer sleeve, forming a cavity with the outer sleeve, and the resin melt can enter the cavity from the bottom or top or both sides of the outer sleeve. The core can move forward and backward in the outer sleeve, and the pressure of the melt in the cavity can be adjusted by adjusting the size of the cavity space formed. The pressure of the melt in the cavity can also be adjusted by the angle between the core and the outer sleeve. The working principle of the forming mold is as follows: the strip formed after impregnation in the impregnation mold is guided to pass through the hole in the middle of the core, and then the inner and outer layer material composite structure is formed in the cavity formed by the core and the outer sleeve filled with mixed melt, and finally it is guided out through the outer sleeve die plate.

[0115] The present application will be further described below with reference to the accompanying drawings.

[0116] Figure 1 The structure of the continuous fiber reinforced polyglycolic acid heat conducting composite material of the present application is shown. As shown in Figure 1 , the cross section of the continuous fiber reinforced polyglycolic acid heat conducting composite material of the present application is circular, which includes the inner core material 0-1 and the outer layer material 0-3 from inside to outside, the inner core material 0-1 is distributed with fiber bundles 0-2 oriented in the longitudinal direction, and the fiber bundles 0-2 are uniformly dispersed in the inner core material 0-1.

[0117] As shown in Figure 2 and Figure 3 , the manufacturing system of the present application includes the fiber frame and fiber guiding device 1, the fiber pretreatment device 2, the first impregnation mold 3, the melt plasticizing feeding device 4, the forming mold 5, the cooling water tank 6, the drying machine 7, the traction machine 8, the granulator 9, the collection box 10, and the electric control system (not shown in the figure) connected in sequence.

[0118] In the manufacturing system, the forming mold 5 is used for the forming of the continuous fiber reinforced polyglycolic acid heat conducting composite material, and its structure is shown in Figure 8 .

[0119] In the manufacturing system, the first impregnation mold 3 is used for the impregnation of the fiber and the first polyglycolic acid resin melt.

[0120] As shown in Figure 4As shown, in one embodiment, the first impregnation die 3 is an adjustable godet position impregnation device, which includes a first impregnation die head A300, the first impregnation die head A300 includes an impregnation die body A7, a fiber inlet A1, a fiber outlet A6, and a melt flow channel A3. At least one first godet A8 is arranged in the die cavity, wherein the first godet A8 is movable between the fiber inlet A1 and the fiber outlet A6, or the first godet A8 is movable in a direction perpendicular to the line connecting the fiber inlet A1 and the fiber outlet A6, or the first godet A8 is movable both between the fiber inlet A1 and the fiber outlet A6 and in a direction perpendicular to the line connecting the fiber inlet A1 and the fiber outlet A6.

[0121] Taking a rectangular first impregnation die head A300 as an example, a plurality of first godets A8 are arranged in the first impregnation die head A300, and the axial direction of each first godet A8 is the width direction of the first impregnation die head A300. Therefore, each first godet A8 is movable in the length direction of the first impregnation die head A300 and is also movable in the height direction, so as to change the position of the first godet A8 in the first impregnation die head A300.

[0122] It can be understood that the axial direction of the first godet A8 can also be the length direction of the first impregnation die head A300. At this time, each first godet A8 is movable in the width direction of the first impregnation die head A300 and is also movable in the height direction of the first impregnation die head A300, so as to change the position of the first godet A8 in the first impregnation die head A300.

[0123] Since the fiber needs to pass around the first godet A8 in the die cavity when walking in the die cavity of the first impregnation die head A300, by changing the position (horizontal position, longitudinal position, etc.) of the first godet A8 in the first impregnation die head A300, the walking path of the fiber in the die cavity can be changed. Therefore, when the required impregnation condition of the fiber changes, it is not necessary to replace a new die, but only to adjust the position of the first godet A8 in the first impregnation die head A300, thereby improving the production efficiency and the continuity of production. At the same time, the number of first impregnation die heads A300 can be reduced, and the production cost can be saved.

[0124] Specifically, the present application is to adjust the position of the first godet A8 by slotting the inner wall of the die cavity of the first impregnation die head A300.

[0125] A first sliding groove A4 is arranged on the first inner wall of the first impregnation die head A300, and the first sliding groove A4 extends between the fiber inlet A1 and the fiber outlet A6 (i.e. Figure 4As shown in the Y-axis direction), the first guide roller A8 moves along the second runner A2 to change its vertical position in the die.

[0126] Further, the first inner wall of the first impregnation die head A300 is also provided with a second runner A2, which extends in a direction perpendicular to the first runner A4 (i.e. Figure 4 As shown in the Y-axis direction), the first guide roller A8 moves along the second runner A2 to change its vertical position in the die.

[0127] It should be noted that the first runner A4 and the second runner A2 can be connected. Thus, the first guide roller A8 can be arbitrarily moved in the longitudinal direction or the transverse direction, so that its position is changed.

[0128] The cross section of the first runner A4 and the second runner A2 can be trapezoidal, circular, arc-shaped or rectangular, and the present application does not limit it.

[0129] Both ends of the first guide roller A8 are provided with an adjusting device (not shown in the figure), which is used to adjust the axial length of the first guide roller A8. The minimum axial length of the first guide roller A8 is less than the distance between the first inner wall and the second inner wall, and the maximum axial length of the first guide roller A8 is greater than the distance between the first inner wall and the second inner wall.

[0130] As shown in the Y-axis direction), the first guide roller A8 moves along the second runner A2 to change its vertical position in the die. Figure 5 As shown in the Y-axis direction), the first guide roller A8 moves along the second runner A2 to change its vertical position in the die.

[0131] After the first module B3, the intermediate module B6 and the second module B7 are connected in sequence, the first module flow channel B31, the intermediate module flow channel B61 and the second module flow channel B71 are connected to form a combined flow channel B4 for the fiber to pass through, wherein the number of intermediate modules B6 is at least one. That is, the first module B3 is the first module, and the second module B7 is the tail module, and there is one or more intermediate modules B6 between them. It should be noted that these intermediate modules B6 are also connected in sequence.

[0132] That is, the number of intermediate modules B6 can be increased or decreased as needed, so that when the impregnation requirements change, different intermediate modules B6 are selected to be combined to form a combined second impregnation die head B300, thereby improving the continuity and production efficiency of production, and saving the cost of additional mold opening.

[0133] Furthermore, by selecting different intermediate modules B6, the shape parameters (such as curvature) of the formed combined flow channel B4 can be changed, thereby altering the flow path of the fiber and melt. This can change the impregnation angle and fiber tension of the fiber at different stations in the mold, ultimately achieving the purpose of adjusting and optimizing the entire impregnation process of the fiber and improving the adaptability of the second impregnation mold head B300 to polyglycolic acid resin and fiber.

[0134] The first module B3, the intermediate module B6, and the second module B7 are placed in the mold frame. The mold frame provides a constraint, ensuring that they are in close contact with each other and thus guaranteeing the sealing of the combined flow channel B4.

[0135] like Figure 5 As shown, an implementation with two intermediate modules B6 is illustrated. Figure 5 In the embodiment shown, the downstream end of the first module flow channel B31 is connected to the upstream end of one of the intermediate module flow channels B61, the two intermediate module flow channels B61 are connected to each other, and the downstream section of the other intermediate module flow channel B61 is connected to the upstream end of the second intermediate module flow channel B71, thereby forming a combined flow channel B4 extending from the fiber inlet B1 to the fiber outlet B8.

[0136] Understandably, different combinations of flow channels B4 can be obtained by selecting different intermediate modules B6.

[0137] like Figure 5 As shown, the downstream end of the first module flow channel B31, the upstream end of the second module flow channel B71, and both ends of the intermediate module flow channel B61 are all located in the same plane and are constructed with standardized connectors B5. In other words, the connections between the first module flow channel B31, the intermediate module flow channel B61, and the second module B71 are made through standardized connectors B5. Since the standardized connectors B5 are all located in the same plane and have the same shape and size, it facilitates the combination and connection between different modules.

[0138] like Figure 6 As shown, in another embodiment of the present invention, the third impregnation mold is a strong turbulent impregnation mold, including a third impregnation mold head C300. The third impregnation mold head C300 includes an impregnation mold outer body C2. The impregnation mold outer body C2 is provided with a fiber inlet channel C3, an impregnation outlet C6, and a melt gap flow channel C1. The fiber inlet channel C3, the impregnation outlet C6, and the melt gap flow channel C1 are all connected to the mold cavity inside the impregnation mold outer body C2.

[0139] The second godet roller is arranged in the die cavity of the impregnation die outer body C2, and the second godet roller comprises at least one driving godet roller C4, and the driving godet roller C4 is driven to rotate by a driving device (not shown in the figure). Since the rotation of the driving godet roller C4 is driven by the driving device rather than being driven by the traction of the fiber, when the fiber passes through the driving godet roller C4, the driving godet roller C4 driven to rotate helps to reduce the traction tension of the fiber and the friction between the fiber and the driving godet roller C4, thereby reducing the breaking of the fiber, ensuring the integrity of the fiber, avoiding the fiber being pulled off, and improving the mechanical properties of the material.

[0140] Preferably, the second godet roller further comprises at least one driven godet roller C5, and the driven godet roller C5 is driven by the fiber passing through the driving godet roller C4; or the driven godet roller C5 is connected with the driving godet roller C4 through a belt mechanism, a gear mechanism or a chain mechanism.

[0141] As shown in Figure 6 , an example with one driving godet roller C4 and two driven godet rollers C5 is shown, wherein the two driven godet rollers C5 are arranged one above the other to extend the impregnation path of the fiber passing therethrough. The heights of the driving godet roller C4 and the driven godet roller C5 in the die cavity can be the same or different.

[0142] Further, the driving device can be a motor, a hydraulic mechanism or a reduction box, etc. capable of driving the driving godet roller C4 to rotate.

[0143] According to the running speed v1 of the fiber entering the die cavity of the impregnation die outer body C2, the tangential speed v2 of the corresponding driving godet roller C4 can be selected, for example, the tangential speed v2 of the driving godet roller C4 is the same as the running speed v1 of the fiber, i.e. v1=v2, so as to reduce the breaking and wear of the fiber, thereby ensuring the integrity of the fiber and promoting the impregnation degree of the fiber, shortening the impregnation time and improving the production efficiency.

[0144] As shown in Figure 2 , the melt plasticizing feeding device 4 is composed of a double screw extruder for melt plasticizing the material. The double screw extruder is a co-rotating double screw extruder, the screw diameter is 25mm-95mm, and the length-diameter ratio is 36:1-65:1. When the melt plasticizing feeding device 4 is composed of one extruder, the melt plasticized melt in the extruder is divided by a melt distributor, respectively enters the impregnation die and the forming die, and the melt flow control valve is used to control the flow of each.

[0145] As shown in Figure 3 , the melt plasticizing feeding device 4 is composed of a double screw extruder for melt plasticizing the material. The double screw extruder is a co-rotating double screw extruder, the screw diameter is 25mm-95mm, and the length-diameter ratio is 36:1-65:1. When the melt plasticizing feeding device 4 is composed of one extruder, the melt plasticized melt in the extruder is divided by a melt distributor, respectively enters the impregnation die and the forming die, and the melt flow control valve is used to control the flow of each.As shown, when the melt plasticizing feed device 4 is composed of two extruders 4-1 and 4-2, the melt plasticized melt of each extruder I 4-1 and extruder II 4-2 is respectively fed into the impregnation die and the forming die. In this embodiment, the melt plasticizing feed device is composed of two extruders I 4-1 and extruder II 4-2, and the melt plasticized melt of each extruder I 4-1 and extruder II 4-2 is respectively fed into the first impregnation die 3 and the forming die 5. The extruder I 4-1 and the extruder II 4-2 can be fed with the same or different materials, so that the composite material with the same or different materials of the inner layer and the outer layer can be prepared.

[0146] The fiber pretreatment device 2 is composed of a combination of a tension roller and a hot oven, which combination releases the tension of the fiber when it enters the hot oven, so as to adapt to fibers of different strengths and avoid the breakage of fibers with small strength before entering the impregnation die. The surface of the tension roller in the fiber pretreatment device 2 needs to be treated with ceramic plating to increase the surface roughness and reduce the friction on the fiber.

[0147] In the manufacturing system, the fiber frame and fiber guide device 1 is used for guiding and untwisting the fiber, and is provided with an automatic control untwisting device and is connected with the traction machine 8 and the electric control system (such as a PLC control device).

[0148] In the manufacturing system, the cooling water tank 6, the drying machine 7, the traction machine 8, the pelletizer 9 and the collection box 10 are conventional devices or apparatuses known to those skilled in the art, and will not be described here.

[0149] Figure 7 A schematic diagram of the second impregnation treatment using the forming die is shown, Figure 8 A sectional view of the forming die used in the second impregnation treatment is shown.

[0150] As shown, Figure 8 In one embodiment, the forming die 5 is composed of a core 5-1, an outer sleeve 5-2 and an outer sleeve die plate 5-3. The core 5-1 is located inside the outer sleeve 5-2 and forms a forming cavity with the outer sleeve 5-2, and the resin melt can enter the forming cavity from the bottom or top or two sides of the outer sleeve 5-2. The core 5-1 can move forward and backward in the outer sleeve 5-2, and the pressure of the melt in the forming cavity can be adjusted by adjusting the size of the forming cavity. The pressure of the melt in the forming cavity can also be adjusted by adjusting the angle between the core 5-1 and the outer sleeve 5-2. The working principle of the forming die 5 is as follows: the strip formed by the inner layer impregnated material after passing through the impregnation die 3 is guided to pass through the hole in the middle of the core 5-1, and then the inner and outer layer material composite structure is formed in the forming cavity filled with mixed melt formed by the core 5-1 and the outer sleeve 5-2, and finally it is guided out through the outer sleeve die plate 5-3.

[0151] AsFigure 7 As shown, the strand 5-4 enters a cavity formed by the core (not shown) and the sheath 5-2, which is filled with the second component melt, where the second component melt is fed into the cavity from the second resin inlet 5-5.

[0152] In the following examples and comparative examples, the following materials were used Figure 3 A continuous fiber-reinforced polyglycolic acid thermally conductive composite material was prepared by using the manufacturing system shown in the figure, wherein the first impregnation treatment used Figure 4 The first impregnation mold shown in the figure, the second impregnation treatment used Figure 8 The molding mold shown in the figure.

[0153] The continuous fiber-reinforced polyglycolic acid thermally conductive composite material and the preparation method thereof provided by the present application will be described in detail below in conjunction with specific examples.

[0154] Unless otherwise defined, the technical terms used in the following examples have the same meanings as generally understood by those skilled in the art to which the present application belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, unless otherwise specified, can be purchased on the market or obtained by existing methods; the reagent amount, unless otherwise specified, is the reagent amount in conventional experimental operation; the experimental method, unless otherwise specified, is a conventional method.

[0155] In each of the examples and comparative examples of the present application, the test method of each performance data is as follows:

[0156] (1) Tensile strength: GB / T 1040-2018;

[0157] (2) Flexural modulus: GB / T 9341-2008;

[0158] (3) Impact strength: GB / T 1843-2008;

[0159] (4) Heat distortion temperature: GB / T 1634-2004, A method, bending stress 1.8 MPa;

[0160] (5) Test method for thermal conductivity of plastics: GBT 3399-1982.

[0161] In each of the examples and comparative examples of the present application, the materials used are as follows:

[0162] (1) Polyglycolic acid: homopolymer polyglycolic acid, melt index 10, 40, 100, 150 g / 10 min (2.16 kg, 230°C), the first two were purchased from Shanghai Pujing Chemical Co., Ltd., and the last two were purchased from Japan Wuhe and Liaoning Jinmei, respectively;

[0163] (2) Glass fiber: Alkali-free glass fiber, diameter 17 μm, linear density 2400 tex, Chongqing International Composite Material Co., Ltd.

[0164] (3) Antioxidant 1010: Irganox 1010, Germany Ciba;

[0165] (4) Antioxidant 168: Irgafos 168, Germany BASF;

[0166] (5) Silane coupling agent: KH-550, Nanjing Youpu Chemical Co., Ltd.

[0167] (6) Calcium stearate: 6.5 wt% Ca, Ino Kai Co., Ltd.

[0168] (7) Thermal conductive main material: Magnesium oxide powder, particle size 4 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0169] Aluminum oxide powder, particle size 10 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0170] Aluminum oxide powder, particle size 40 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0171] (8) Thermal conductive auxiliary material: Aluminum nitride powder, particle size 10 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0172] Aluminum nitride powder, particle size 50 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0173] Boron nitride powder, particle size 10 μm, Shanghai Bitu New Material Technology Co., Ltd.

[0174] Example 1

[0175] (1) 100 parts by weight of polyglycolic acid (melt index 40 g / 10 min) was mixed with 1 part by weight of silane coupling agent (KH550), 0.2 parts by weight of antioxidant 168, 0.3 parts by weight of antioxidant 1010, and 0.2 parts by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then sent to the impregnation mold after melting.

[0176] (2) The continuous glass fiber was introduced into the impregnation mold under the action of the traction machine, and impregnated and dispersed with the above-mentioned melt to form a sample, which was used as an inner layer material, wherein the glass fiber content was 60 parts by weight.

[0177] (3) 100 parts by weight of polyglycolic acid (melt index 10 g / 10 min) was mixed with 120 parts by weight of a heat-conducting main material (4 μm particle size magnesium oxide), 12 parts by weight of a heat-conducting auxiliary material (10 μm particle size aluminum nitride), 2 parts by weight of a silane coupling agent (KH550), 0.1 part by weight of an antioxidant 1010, and 0.5 parts by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and the mixture was used as an outer layer material and fed into a double-screw extruder connected to a molding die.

[0178] (4) The inner layer material was introduced into the molding die under the action of a puller, guided through the hole in the middle of the core, and formed into a composite structure of the inner and outer layer materials in the cavity filled with the mixed melt of the outer layer material between the core and the outer sleeve. Finally, the material was discharged through the outer sleeve die plate.

[0179] (5) The amount of the outer layer material was adjusted by selecting the size (4 mm) of the outer sleeve die plate of the molding die, and the pellet length of the obtained polyglycolic acid composite material was controlled to 15 mm by adjusting the cutter rotation speed of a pelletizer.

[0180] (6) The polyglycolic acid composite material obtained by the above method was injection molded into a standard sample bar, and performance tests were performed. The test results are shown in Table 2.

[0181] Comparative Example 1

[0182] (1) 100 parts by weight of polyglycolic acid (melt index 40 g / 10 min) was mixed with 1 part by weight of a silane coupling agent (KH550), 0.2 part by weight of an antioxidant 168, 0.3 part by weight of an antioxidant 1010, 0.2 part by weight of calcium stearate, and 60 parts by weight of glass fiber (25 mm) in a high-speed mixer at 50°C for 3 minutes.

[0183] (2) 100 parts by weight of polyglycolic acid (melt index 10 g / 10 min) was mixed with 120 parts by weight of a heat-conducting main material (4 μm particle size magnesium oxide), 12 parts by weight of a heat-conducting auxiliary material (10 μm particle size aluminum nitride), 2 parts by weight of a silane coupling agent (KH550), 0.1 part by weight of an antioxidant 1010, and 0.5 parts by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes.

[0184] (3) The two mixtures were added together to a double-screw extruder, and melt granulation was performed. The obtained polyglycolic acid composite material had a particle length of 15 mm.

[0185] (4) The polyglycolic acid composite material obtained by the above method was injection molded into a standard sample bar, and performance tests were performed. The test results are shown in Table 2.

[0186] Comparative Example 2

[0187] (1) 100 parts by weight of polyglycolic acid (melt index 40 g / 10 min) was mixed with 1 part by weight of silane coupling agent (KH550), 0.2 part by weight of antioxidant 168, 0.3 part by weight of antioxidant 1010, 0.2 part by weight of calcium stearate, 60 parts by weight of glass fiber (25 mm) in a high-speed mixer at 50°C for 3 minutes, and then melt granulated to obtain polyglycolic acid composite 1.

[0188] (2) 100 parts by weight of polyglycolic acid (melt index 10 g / 10 min) was mixed with 120 parts by weight of heat-conducting main material (4 μm particle size magnesium oxide), 12 parts by weight of heat-conducting auxiliary material (10 μm particle size aluminum nitride), 2 parts by weight of silane coupling agent (KH550), 0.1 part by weight of antioxidant 1010, 0.5 part by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then melt granulated to obtain polyglycolic acid composite 2.

[0189] (3) Polyglycolic acid composites 1 and 2 were added together to a twin-screw extruder and melt granulated to obtain polyglycolic acid composite particles having a length of 15 mm.

[0190] (4) The polyglycolic acid composite prepared by the above method was injection molded into a standard sample bar, and performance tests were performed. The test results are shown in Table 2.

[0191] Example 2

[0192] (1) 100 parts by weight of polyglycolic acid (melt index 10 g / 10 min) was mixed with 0.05 part by weight of silane coupling agent (KH550), 0.05 part by weight of antioxidant 168, 0.05 part by weight of antioxidant 1010, 0.5 part by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then melt granulated to obtain polyglycolic acid composite 2.

[0193] (2) Continuous glass fiber was introduced into the impregnation mold under the action of a traction machine, impregnated and dispersed with the above melt to form a sample bar, which was used as an inner layer material, and the glass fiber content was 60 parts by weight.

[0194] (3) 100 parts by weight of polyglycolic acid (melt index 150 g / 10 min) was mixed with 100 parts by weight of heat-conducting main material (4 μm particle size magnesium oxide), 30 parts by weight of heat-conducting auxiliary material (10 μm particle size boron nitride), 0.1 part by weight of silane coupling agent (KH550), 0.2 part by weight of antioxidant 1010, 0.2 part by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then melt granulated to obtain polyglycolic acid composite particles having a length of 15 mm.

[0195] (4) The inner layer material is guided to pass through the hole in the middle of the core under the action of the traction machine, and is formed in the cavity filled with the mixed melt of the outer layer material formed by the core and the outer sleeve, so that the inner and outer layer materials are compounded and formed, and finally is guided out through the outer sleeve die plate.

[0196] (5) The amount of the outer layer material is adjusted by selecting the size (4 mm) of the outer sleeve die plate of the forming die, and the cutter rotating speed of the granulator is adjusted, so that the length of the obtained polyglycolic acid composite material is 10 mm.

[0197] (6) The polyglycolic acid composite material prepared by the above method is injection molded into a standard sample bar for performance testing. The test results are shown in Table 2.

[0198] Example 3

[0199] (1) 100 parts by weight of polyglycolic acid (melt index 150 g / 10 min) is mixed with 2 parts by weight of silane coupling agent (KH550), 0.5 parts by weight of antioxidant 168, 0.5 parts by weight of antioxidant 1010 and 1 part by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then is sent into an impregnation mold after melting.

[0200] (2) The continuous glass fiber is guided into the impregnation mold under the action of the traction machine, and is impregnated and dispersed with the above-mentioned melt to form a sample bar, which is used as the inner layer material, and the content of the glass fiber is 60 parts by weight.

[0201] (3) 100 parts by weight of polyglycolic acid (melt index 40 g / 10 min) is mixed with 80 parts by weight of heat-conducting main material (10 μm particle size of aluminum oxide), 60 parts by weight of heat-conducting auxiliary material (10 μm particle size of aluminum nitride), 0.05 parts by weight of silane coupling agent (KH550), 1 part by weight of antioxidant 1010 and 1 part by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and is used as the outer layer material and is sent into a double-screw extruder connected with a forming die.

[0202] (4) The inner layer material is guided to pass through the hole in the middle of the core under the action of the traction machine, and is formed in the cavity filled with the mixed melt of the outer layer material formed by the core and the outer sleeve, so that the inner and outer layer materials are compounded and formed, and finally is guided out through the outer sleeve die plate.

[0203] (5) The amount of the outer layer material is adjusted by selecting the size (4 mm) of the outer sleeve die plate of the forming die, and the cutter rotating speed of the granulator is adjusted, so that the length of the obtained polyglycolic acid composite material is 3 mm.

[0204] (6) The polyglycolic acid composite material prepared by the above method is injection molded into a standard sample bar for performance testing. The test results are shown in Table 2.

[0205] Example 4

[0206] (1) 100 parts by weight of polyglycolic acid (melt index 100 g / 10 min) was mixed with 0.5 parts by weight of silane coupling agent (KH550), 0.1 parts by weight of antioxidant 168, 0.2 parts by weight of antioxidant 1010, and 0.2 parts by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, and then fed into an impregnation mold after melting.

[0207] (2) Continuous glass fibers were introduced into the impregnation mold under the action of a pulling machine, impregnated and dispersed with the above-mentioned melt to form a sample bar, which was used as the inner layer material, and the glass fiber content was 60 parts by weight.

[0208] (3) 100 parts by weight of polyglycolic acid (melt index 100 g / 10 min) was mixed with 50 parts by weight of a heat-conducting main material (4 μm particle size magnesium oxide), 30 parts by weight of a heat-conducting auxiliary material (10 μm particle size aluminum nitride), 1 part by weight of silane coupling agent (KH550), 0.5 parts by weight of antioxidant 1010, and 0.2 parts by weight of calcium stearate in a high-speed mixer at 50°C for 3 minutes, which was used as the outer layer material, and was fed into a double-screw extruder connected to a forming mold.

[0209] (4) The inner layer material was introduced into the forming mold under the action of the pulling machine, guided through the hole in the middle of the core, and formed in the cavity filled with the mixed melt of the outer layer material between the core and the outer sleeve, to realize the molding of the inner and outer layer material composite structure, and finally guided out through the outer sleeve die plate.

[0210] (5) The amount of outer layer material was adjusted by selecting the size (4 mm) of the outer sleeve die plate of the forming mold, and the cutter speed of the granulator was adjusted to control the length of the obtained polyglycolic acid composite material to be 4 mm.

[0211] (6) The polyglycolic acid composite material prepared by the above method was injection molded into a standard sample bar, and performance tests were conducted, and the test results are shown in Table 2.

[0212] Comparative Example 3

[0213] The preparation process was the same as that of Example 4, except that 50 parts by weight of a heat-conducting main material (4 μm particle size magnesium oxide) and 30 parts by weight of a heat-conducting auxiliary material (10 μm particle size aluminum nitride) were not added in step (3). The polyglycolic acid composite material was injection molded into a standard sample bar, and performance tests were conducted, and the test results are shown in Table 2.

[0214] Example 5

[0215] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0216] Example 6

[0217] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0218] Comparative Example 4

[0219] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0220] Comparative Example 5

[0221] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0222] Example 7

[0223] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0224] Example 8

[0225] The preparation process is the same as that of Example 4, except that in step (3), 80 parts by weight of the heat-conducting main material (magnesium oxide with a particle size of 4 μm) is added, and no heat-conducting auxiliary material (aluminum nitride with a particle size of 10 μm) is added. The polyglycolic acid composite is injection molded into a standard sample bar, and performance tests are conducted, and the test results are shown in Table 2.

[0226] Table 1: Table of main component proportions in the composite materials of the examples and comparative examples

[0227]

[0228]

[0229] Table 2 Test results of material properties of examples and comparative examples

[0230]

[0231] From the test results of performance of Example 1 and Comparative Examples 1 and 2, it can be seen that the performance of the composite material obtained by directly melt blending the inner and outer layer materials is much lower than that of the polyglycolic acid composite material prepared according to the preparation method described in the application, which shows that the high content of the thermally conductive filler can be uniformly dispersed in the outer layer material by the technical solution of the application, and the oriented distribution of the glass fiber in the inner core material can be maintained, and finally the polyglycolic acid thermally conductive composite material with excellent mechanical properties and thermal conductivity can be obtained.

[0232] From the test results of performance of Example 4 and Comparative Example 3, it can be seen that the thermally conductive filler can significantly improve the thermal conductivity of the composite material, and has a beneficial effect on the tensile strength, flexural modulus and heat distortion temperature of the composite material.

[0233] From the test results of performance of Example 4 and Examples 5-6, it can be seen that the combination of the thermally conductive main material and the thermally conductive auxiliary material can not only make the composite material obtain better thermal conductivity, but also be beneficial to improving the mechanical properties of the composite material, compared with adding the thermally conductive main material or the thermally conductive auxiliary material alone.

[0234] From the test results of performance of Example 4 and Comparative Examples 4-5, it can be seen that adding the thermally conductive filler to the outer layer material can have better mechanical properties and thermal conductivity, compared with adding the thermally conductive filler to the inner core material or adding it to both the inner core material and the outer layer material.

[0235] From the test results of performance of Example 4 and Examples 7-8, it can be seen that the combination of the thermally conductive main material with different particle sizes has better thermal conductivity and mechanical properties of the composite material, compared with a single particle size; the thermally conductive auxiliary material with a small particle size is more beneficial to the thermal conductivity and mechanical properties of the composite material, compared with a large particle size. This is mainly because the thermally conductive main materials with different particle sizes have different packing densities and thermal conductivity. The thermally conductive main material with a large particle size (20-40 μm) has higher thermal conductivity, but its packing density is lower, and more voids are generated between the particles. The thermally conductive main material with a small particle size (1 μm-10 μm) has high packing density and small voids between the particles, but its thermal conductivity in the resin is lower. The thermally conductive main material with a small particle size can fill the thermally conductive main material with a large particle size, and the introduction of the thermally conductive auxiliary material can build a thermally conductive network with less voids and good connectivity, which can improve the thermal conductivity of the composite material and also improve the mechanical properties of the product.

[0236] It should be noted that the foregoing examples have been provided merely for the purposes of illustration and are not intended to limit the application in any way. Descriptions and examples of materials and processes of the application are intended to be illustrative not limiting. Any modifications of the application and other applications of the application will occur to those skilled in the art to which the application pertains and many options for modification of the application will suggest themselves. The application lies in the broadest aspects of the art, and there are many alternatives for the application of the application.

Claims

1. A continuous fiber-reinforced polyglycolic acid thermally conductive composite material, characterized in that, It includes an inner core material and at least one outer layer material; the inner core material includes a first polyglycolic acid resin, glass fiber, and a first additive, the glass fiber extending continuously from one end of the inner core material to its opposite end; the outer layer material encloses the inner core material, and the outer layer material includes a second polyglycolic acid resin, a thermally conductive filler, and a second additive. In the core material, the amount of the first polyglycolic acid resin is 100 parts by weight, and the amount of glass fiber is 10-200 parts by weight. In the outer layer material, the amount of the second polyglycolic acid resin is 100 parts by weight, and the amount of the thermally conductive filler is 20-150 parts by weight. In the composite material, the amount of the first polyglycolic acid resin is 100 parts by weight, and the amount of the second polyglycolic acid resin is 50-100 parts by weight. The thermally conductive filler includes a thermally conductive main material and a thermally conductive auxiliary material. The thermally conductive main material is selected from metal oxides and / or metal hydroxides, and the thermally conductive auxiliary material is selected from inorganic powders.

2. The composite material according to claim 1, characterized in that, In the core material, the amount of the first polyglycolic acid resin is 100 parts by weight, and the amount of glass fiber is 10-150 parts by weight.

3. The composite material according to claim 2, characterized in that, In the core material, the amount of the first polyglycolic acid resin is 100 parts by weight, and the amount of glass fiber is 20-150 parts by weight.

4. The composite material according to any one of claims 1-3, characterized in that, Based on the total weight of the thermally conductive filler, the content of the main thermally conductive material is 50-98 wt%, and the content of the auxiliary thermally conductive material is 2-50 wt%.

5. The composite material according to any one of claims 1-3, characterized in that, The thermally conductive main material is selected from at least one of alumina, antimony trioxide, titanium dioxide, magnesium oxide, aluminum hydroxide, and magnesium hydroxide. And / or, the particle size of the thermally conductive main material is 1-100 μm; And / or, the inorganic powder is selected from at least one of carbon nanotubes, carbon black, flake graphite, graphene, boron nitride, boron carbide, aluminum nitride, and silicon carbide; And / or, the particle size of the inorganic powder is 1~100μm.

6. The composite material according to claim 5, characterized in that, The thermally conductive main material is selected from at least one of alumina, magnesium oxide, aluminum hydroxide, and magnesium hydroxide; And / or, the particle size of the thermally conductive main material is 1-40 μm; And / or, the inorganic powder is selected from at least one of boron nitride, aluminum nitride, and silicon carbide; And / or, the particle size of the inorganic powder is 1-50 μm.

7. The composite material according to any one of claims 1-3, characterized in that, The first polyglycolic acid resin and the second polyglycolic acid resin may be the same or different, and each is independently selected from homopolymer polyglycolic acid and / or copolymer polyglycolic acid; And / or, the melt flow rate of the first polyglycolic acid resin at 230°C and 2.16 kg is 5-500 g / 10 min; And / or, the melt flow rate of the second polyglycolic acid resin at 230°C and 2.16 kg is 5-500 g / 10 min.

8. The composite material according to claim 7, characterized in that, The content of glycolic acid monomer in the copolymerized polyglycolic acid is ≥90 mol%; And / or, the melt flow rate of the first polyglycolic acid resin at 230°C and 2.16 kg is 10-200 g / 10 min; And / or, the melt flow rate of the second polyglycolic acid resin at 230°C and 2.16 kg is 10-200 g / 10 min.

9. The composite material according to claim 8, characterized in that, The content of glycolic acid monomer in the copolymerized polyglycolic acid is ≥95 mol%; And / or, the melt flow rate of the first polyglycolic acid resin at 230°C and 2.16 kg is 10-100 g / 10 min; And / or, the melt flow rate of the second polyglycolic acid resin at 230°C and 2.16 kg is 10-100 g / 10 min.

10. The composite material according to any one of claims 1-3, characterized in that, The amount of the first polyglycolic acid resin is based on 100 parts by weight, and the first additive includes at least one of 0.05-5 parts by weight of a first compatibilizer, 0.1-3 parts by weight of a first antioxidant, and 0.1-1 parts by weight of a first lubricant; And / or, the amount of the second polyglycolic acid resin is 100 parts by weight, and the second additive includes at least one of 0.05-5 parts by weight of a second compatibilizer, 0.1-3 parts by weight of a second antioxidant, and 0.1-1 parts by weight of a second lubricant.

11. The composite material according to claim 10, characterized in that, The amount of the first polyglycolic acid resin is 100 parts by weight, and the first additive includes at least one of 0.05-2 parts by weight of a first compatibilizer, 0.1-1 parts by weight of a first antioxidant, and 0.2-1 parts by weight of a first lubricant; And / or, the amount of the second polyglycolic acid resin is 100 parts by weight, and the second additive includes at least one of 0.05-2 parts by weight of a second compatibilizer, 0.1-1 parts by weight of a second antioxidant, and 0.2-1 parts by weight of a second lubricant.

12. The composite material according to claim 10, characterized in that, The first compatibilizer and the second compatibilizer may be the same or different, and each is independently selected from at least one coupling agent; And / or, the first antioxidant and the second antioxidant may be the same or different, and each is independently selected from at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 2246, antioxidant CA and antioxidant 626; And / or, the first lubricant and the second lubricant may be the same or different, and each is independently selected from at least one of ethylene bis-stearamide, calcium stearate, mono-fatty acid glyceride, polyethylene wax, erucamide, and pentaerythritol stearate.

13. The composite material according to claim 12, characterized in that, The first compatibilizer and the second compatibilizer may be the same or different, and each is independently selected from at least one of silane coupling agents, titanate coupling agents, and organochromium complex coupling agents; And / or, the first antioxidant and the second antioxidant may be the same or different, and each may be independently selected from at least one of antioxidant 1010 and antioxidant 168.

14. The composite material according to claim 13, characterized in that, The first compatibilizer and the second compatibilizer may be the same or different, and each is independently selected from silane coupling agents.

15. The composite material according to any one of claims 1-3, characterized in that, The core material does not contain non-oriented short fibers.

16. The composite material according to claim 15, characterized in that, The core material is composed of a first polyglycolic acid resin, glass fiber, and a first additive.

17. A method for preparing the composite material as described in any one of claims 1-16, characterized in that, include: S1. The first polyglycolic acid resin and the first additive are mixed and melted to obtain the first component melt; S2. The continuous glass fiber is subjected to a first impregnation treatment with the first component melt in step S1 to form a filamentous core material; S3. The second polyglycolic acid resin, the thermally conductive filler, and the second additive are mixed and melted to obtain the second component melt; S4. The core material obtained in step S2 is subjected to at least one second impregnation treatment with at least one second component melt obtained in step S3 to obtain a continuous glass fiber reinforced polyglycolic acid thermally conductive composite material.

18. The preparation method according to claim 17, characterized in that, The mixing conditions for step S1 are: temperature of 40-60℃ and time of 3-5 min; and / or the melting temperature of step S1 is 230-260℃. And / or, the mixing conditions in step S3 are: temperature of 40-60℃, time of 3-5 min; and / or the melting temperature in step S3 is 230-260℃; And / or, step S2 further includes: dispersing and preheating the continuous glass fibers before subjecting them to the first impregnation treatment; And / or, step S4 further includes: after the second impregnation treatment, the material obtained by the second impregnation treatment is subjected to pull-out, stripping, cooling, drying and pelletizing treatment to obtain a continuous glass fiber reinforced polyglycolic acid thermally conductive composite material.

19. The preparation method according to claim 18, characterized in that, The preheating temperature is 80-250℃.

20. The preparation method according to any one of claims 17-19, characterized in that, In step S2, the first impregnation process is performed in a first impregnation mold. The first impregnation mold is an adjustable impregnation mold, which includes a fiber inlet, a fiber outlet, and a melt flow channel. At least one first guide roller is provided in the mold cavity of the first impregnation mold. The first guide roller is movable between the fiber inlet and the fiber outlet. And / or, the first guide roller is movable along a direction perpendicular to the line connecting the fiber inlet and the fiber outlet.

21. The preparation method according to any one of claims 17-19, characterized in that, In step S2, the first impregnation process is carried out in the second impregnation mold. The second impregnation mold is a combined impregnation mold, which includes a first module, an intermediate module, and a second module connected in sequence. The first module is provided with a fiber inlet and a first module flow channel. The second module is provided with a fiber outlet and a second module flow channel. The intermediate module is provided with an intermediate module flow channel. After the first module, the intermediate module, and the second module are connected in sequence, the first module flow channel, the intermediate module flow channel, and the second module flow channel are connected to form a combined flow channel for the fiber to pass through.

22. The preparation method according to any one of claims 17-19, characterized in that, In step S2, the first impregnation process is carried out in a third impregnation mold. The third impregnation mold is a strong turbulent impregnation mold. The third impregnation mold includes a fiber inlet channel, an impregnation outlet, and a melt gap channel. The fiber inlet channel, the impregnation outlet, and the melt gap channel are all connected to the mold cavity inside the third impregnation mold. A second guide roller is provided inside the mold cavity of the third impregnation mold. The second guide roller includes at least one active guide roller, which is driven to rotate by a driving device.

23. The application of the composite material according to any one of claims 1-16 or the composite material prepared by the preparation method according to any one of claims 17-22 in the fields of disposable thermal conductive materials, controllable degradable thermal conductive materials and / or in the fields of medical aesthetics, electrical components, oilfield chemicals and engineering plastics.

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