A plant fiber composite polypropylene material and its preparation method and application

Abstract

The present invention discloses a plant fiber composite polypropylene material and its preparation method and application. The raw materials of the plant fiber composite polypropylene material include the following components calculated by weight: 76-96 parts of polypropylene, 10-60 parts of plant fiber masterbatch, 3-6 parts of bio-based compatibilizer, 3-6 parts of flexible plasticizer, 5-30 parts of high-efficiency toughening agent, 0.1-0.4 parts of antioxidant and 0.2-0.6 parts of lubricant; wherein the bio-based compatibilizer includes bio-based itaconic anhydride grafted polypropylene. The polypropylene material of the present invention has a plant filamentous appearance or a granular appearance, and through the introduction of the bio-based compatibilizer, the plant fiber and the polypropylene material have excellent interfacial compatibility. At the same time, through the synergistic effect of the high-efficiency toughening agent and the flexible plasticizer, the material maintains high toughness at room temperature, and greatly improves the impact resistance of the material at low temperature, so as to expand the application of the plant fiber composite polypropylene material in the low-temperature field.

Description

Technical Field

[0001] The present invention relates to the field of composite modification of bio-based compatibilizers and polymer materials, and in particular to a plant fiber composite polypropylene material and a preparation method and application thereof. Background Art

[0002] At present, bio-based materials are gradually becoming the key direction for the development of new materials in the future, and plant fiber materials have attracted widespread attention from people in the materials field because of their advantages such as being green, environmentally friendly, and easily accessible. However, the direct application areas of plant fiber materials are very limited, so they are often used in combination with polymer materials such as polypropylene, polyethylene, and ABS. This not only greatly broadens the application areas of plant fibers, but also the introduction of plant fibers improves the rigidity of polymer materials and the special appearance of plant fibers. However, since plant fiber materials contain a large amount of cellulose, the presence of a large number of hydroxyl groups in cellulose causes interfacial incompatibility with polymer materials, resulting in a significant decrease in the mechanical properties of plant fiber composite polymer materials, especially in toughness and low-temperature toughness, which show a cliff-like drop, thus greatly limiting the application of plant fiber composite polymer materials.

[0003] Therefore, how to improve the interfacial compatibility between plant fibers and polymer materials (such as polypropylene materials), as well as how to improve the toughness and low-temperature impact strength of plant fiber composite polymer materials, has become a top priority for plant fiber composite materials.

[0004] Taking polypropylene as an example, the main method to improve the interfacial compatibility between plant fibers and polypropylene is to add an interfacial compatibilizer (maleic anhydride grafted polypropylene). However, a large number of experiments have shown that this method has a very limited effect on improving interfacial compatibility. This is mainly because the grafting rate of commercial maleic anhydride grafted polypropylene is low, and the combination of maleic anhydride and the hydroxyl groups in cellulose is very limited. At the same time, the main method to improve the impact resistance of plant fiber composites is to add rubber toughening agents, such as POE and other elastomers. However, this method not only significantly increases material costs and reduces the fluidity of the material, but also, although it improves the room temperature impact strength of the material, the improvement in impact resistance at low temperatures is very limited, and it is often not applicable to the use requirements in some low temperature scenarios. Summary of the Invention

[0005] The main purpose of the present invention is to provide a plant fiber composite polypropylene material and a preparation method and application thereof, so as to overcome the shortcomings of the prior art.

[0006] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0007] The embodiment of the present invention provides a plant fiber composite polypropylene material, wherein the raw materials of the plant fiber composite polypropylene material include the following components calculated by weight: 76-96 parts of polypropylene, 10-60 parts of plant fiber masterbatch, 3-6 parts of bio-based compatibilizer, 3-6 parts of flexible plasticizer, 5-30 parts of high-efficiency toughening agent, 0.1-0.4 parts of antioxidant and 0.2-0.6 parts of lubricant;

[0008] Wherein, the bio-based compatibilizer includes bio-based itaconic anhydride grafted polypropylene.

[0009] The present invention also provides a method for preparing the aforementioned plant fiber composite polypropylene material, which comprises:

[0010] Polypropylene, bio-based compatibilizer, flexible plasticizer, high-efficiency toughening agent, antioxidant and lubricant are mixed evenly and added to a twin-screw extruder through a main feed port. At the same time, plant fiber masterbatch is added to the twin-screw extruder through a side feed port, and then melt-extruded and granulated to obtain the plant fiber composite polypropylene material.

[0011] The embodiment of the present invention further provides use of the aforementioned plant fiber composite polypropylene material in preparing a low-temperature resistant and high-impact composite material.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The present invention uses a bio-based compatibilizer PP-g-ITA, which not only has the advantage of a bio-based source, but also has a higher reactivity than maleic anhydride, so the compatibilizer has a higher grafting rate. At the same time, the double bond of itaconic anhydride is on the side chain, which has better flexibility than maleic anhydride. The high grafting rate cooperates with the flexibility of the molecular chain, thereby bringing about better interfacial compatibility.

[0014] (2) The plant fiber composite polypropylene material provided by the present invention abandons the traditional POE toughening, and preferentially uses SEBS as a high-efficiency toughening agent, and cooperates with biocompatible ESO as a plasticizer (SEBS can absorb ESO and make the SEBS molecular chain more stretchable, with more superior molecular chain flexibility at low temperatures). It can not only improve the room temperature impact strength of the material, but also maintain sufficient molecular chain flexibility at low temperatures, thereby greatly improving the toughness and impact strength of the material at low temperatures (-20°C); at the same time, the plant fiber composite polypropylene material has a plant filamentous appearance or a granular appearance;

[0015] (3) The plant fiber composite polypropylene material provided by the present invention preferentially prepares plant fiber into plant fiber masterbatch through a three-dimensional high-efficiency mixing system, successfully solving the problem that high-content plant fiber is difficult to force-feed into a twin-screw extruder and the problem of stratification after mixing;

[0016] (4) The plant fiber composite polypropylene material provided by the present invention has a plant fiber masterbatch added through a side feed port in the process, which retains the length and excellent performance of the plant fiber to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1a-Figure 1b This is an SEM image of the coconut fiber composite polypropylene material prepared in Comparative Example 2 of the present invention;

[0019] Figure 2a-2b 1 is a SEM image of the coconut fiber composite polypropylene material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The technical solution of the present invention will be clearly and completely described below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making any creative effort shall fall within the scope of protection of the present invention.

[0021] Specifically, as one aspect of the technical solution of the present invention, it involves a plant fiber composite polypropylene material, the raw materials of which include the following components calculated by weight: 76-96 parts of polypropylene, 10-60 parts of plant fiber masterbatch, 3-6 parts of bio-based compatibilizer, 3-6 parts of flexible plasticizer, 5-30 parts of high-efficiency toughening agent, 0.1-0.4 parts of antioxidant and 0.2-0.6 parts of lubricant;

[0022] Wherein, the bio-based compatibilizer includes bio-based itaconic anhydride grafted polypropylene.

[0023] In some preferred embodiments, the polypropylene includes homopolypropylene and / or block copolymer polypropylene, but is not limited thereto.

[0024] Furthermore, the melt index of the polypropylene is 10-60 g / 10 min (230° C., 2.16 kg).

[0025] In some preferred embodiments, the plant fiber masterbatch is mainly prepared by reacting plant fiber, polypropylene, antioxidant 168 and antioxidant 1010.

[0026] Furthermore, the plant fiber includes any one or more combinations of coconut fiber, straw fiber, red pine fiber, rice husk fiber, jute fiber, and wheat straw fiber, but is not limited thereto.

[0027] In some preferred embodiments, the total amount of polypropylene contained in the raw materials of the plant fiber composite polypropylene material is 100 parts by weight.

[0028] In some preferred embodiments, the bio-based itaconic anhydride grafted polypropylene is mainly prepared by reacting polypropylene, itaconic anhydride, dicumyl peroxide and styrene.

[0029] Furthermore, the preparation method of the bio-based itaconic anhydride grafted polypropylene includes: mixing polypropylene, itaconic anhydride, dicumyl peroxide and styrene, and melt-extruding through a twin-screw extruder to obtain the bio-based itaconic anhydride grafted polypropylene; wherein the twin-screw melt extrusion adopts a screw length-to-diameter ratio of 42-52:1, an extrusion temperature of 160°C to 185°C, a screw speed of 200-400rpm, a homogenization time of 2 to 4h, and a discharge temperature below 40°C.

[0030] Furthermore, the weight ratio of the polypropylene, itaconic anhydride, dicumyl peroxide and styrene is 100:3-5:0.4-0.8:0.1-0.3.

[0031] Furthermore, the itaconic anhydride includes fully bio-based itaconic anhydride, which is prepared by hydrolyzing starch and fermenting it with Aspergillus terreus.

[0032] Furthermore, the itaconic anhydride is prepared by hydrolyzing starch into glucose and then fermenting it with Aspergillus terreus at 37°C.

[0033] Furthermore, the raw materials of the bio-based itaconic anhydride grafted polypropylene include the following components calculated by weight: 100 parts of polypropylene, 3 parts of itaconic anhydride, 0.6 parts of dicumyl peroxide and 0.2 parts of styrene.

[0034] In some preferred embodiments, the flexible plasticizer includes epoxidized soybean oil (EOS) and / or paraffin oil, but is not limited thereto.

[0035] Furthermore, the flexible plasticizer is epoxidized soybean oil.

[0036] In some preferred embodiments, the high-efficiency toughening agent includes any one or more combinations of hydrogenated styrene-butadiene block copolymer (SEBS), ethylene propylene diene monomer (EPDM), silicone rubber, thermoplastic elastomer TPE, and thermoplastic elastomer TPV, and is not limited thereto.

[0037] Furthermore, the high-efficiency toughening agent is a hydrogenated styrene-butadiene block copolymer.

[0038] In some preferred embodiments, the antioxidant includes any one or more combinations of antioxidant 1010, antioxidant 168, antioxidant 264, antioxidant 1076, antioxidant 1330, and antioxidant TBHQ;

[0039] In some preferred embodiments, the lubricant comprises stearate and / or wax compounds.

[0040] Furthermore, the stearate includes any one or more combinations of zinc stearate, magnesium stearate, and calcium stearate, but is not limited thereto.

[0041] Furthermore, the wax compound includes polyethylene wax and / or oxidized polyethylene wax, but is not limited thereto.

[0042] Another aspect of the embodiments of the present invention further provides a method for preparing the aforementioned plant fiber composite polypropylene material, which comprises:

[0043] Polypropylene, bio-based compatibilizer, flexible plasticizer, high-efficiency toughening agent, antioxidant and lubricant are mixed evenly and added to a twin-screw extruder through a main feed port. At the same time, plant fiber masterbatch is added to the twin-screw extruder through a side feed port, and then melt-extruded and granulated to obtain the plant fiber composite polypropylene material.

[0044] Furthermore, the process parameters adopted by the twin-screw extruder include: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding speed is 10-30kg / h, the main engine speed is 200-500rpm, and the side feeding speed is 0.5-24kg / h.

[0045] In some preferred embodiments, the preparation method further comprises: melt-mixing the plant fiber, polypropylene, antioxidant 168 and antioxidant 1010, and then granulating them through a single-screw extruder to obtain the plant fiber masterbatch.

[0046] Furthermore, the weight ratio of the plant fiber, polypropylene, antioxidant 168 and antioxidant 101 is 150:100-150:0.1-0.4:0.1-0.4.

[0047] In some preferred embodiments, the preparation method of the plant fiber masterbatch includes: uniformly mixing 150 parts of plant fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 according to parts by mass, selecting the GELIMAT high-efficiency blending system, quickly generating heat during the high-speed operation of the machine, quickly making the plant fiber and polypropylene material uniformly mixed in a molten state, and then granulating through a single-screw extruder to obtain the plant fiber masterbatch.

[0048] In some preferred embodiments, the preparation method further comprises: mixing polypropylene, itaconic anhydride, dicumyl peroxide and styrene, and melt-extruding the mixture through a twin-screw extruder to obtain a bio-based compatibilizer;

[0049] The twin-screw melt extrusion adopts a screw length-diameter ratio of 42-52:1, an extrusion temperature of 160°C to 185°C, a screw speed of 200-400rpm, a homogenization time of 2 to 4h, and a discharge temperature below 40°C.

[0050] Furthermore, the weight ratio of the polypropylene, itaconic anhydride, dicumyl peroxide and styrene is 100:3-5:0.4-0.8:0.1-0.3.

[0051] When coconut fiber is directly mixed with other raw materials in the present invention, it cannot be fed smoothly into the twin screw through the feed port, and a large amount of coconut shreds will remain in the main feeding screw. Therefore, the GELIMAT high-efficiency blending system is required to perform mixing and dispersion to make the coconut fiber into plant fiber masterbatch.

[0052] In some preferred embodiments, the preparation method further comprises: drying the product obtained by the melt extrusion granulation process, wherein the drying process is carried out at a temperature of 90-110° C. and for a time of 3-6 hours.

[0053] In some more specific embodiments, the method for preparing the plant fiber composite polypropylene material comprises:

[0054] S1: Drying the plant fiber masterbatch in an oven;

[0055] S2: Weigh the raw materials according to weight: polypropylene, flexible plasticizer, high-efficiency toughening agent, bio-based compatibilizer, antioxidant and lubricant and mix them evenly;

[0056] S3: The evenly mixed raw materials are added to the twin-screw extruder through the main feeding port; the dried plant fiber masterbatch is added to the twin-screw extruder through the side feeding port;

[0057] S4: After extrusion granulation, the particles are dried to obtain the plant fiber composite polypropylene material.

[0058] Furthermore, the drying temperature in step S1 is set to 120° C., and the drying time is 2 h to 4 h.

[0059] Furthermore, the parameters of the twin-screw extruder in step S3 are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 10-30kg / h, the main engine speed is 200-500rpm, and the side feeding speed is 0.5-24kg / h.

[0060] Furthermore, the drying temperature in step S4 is 90-110° C., and the drying time is 3-6 hours.

[0061] Another aspect of the embodiments of the present invention further provides use of the plant fiber composite polypropylene material in preparing a low-temperature resistant and high-impact composite material.

[0062] For example, the plant fiber composite polypropylene material of the present invention can be used in an environment of -20°C.

[0063] For example, in the fields of automotive parts, daily necessities and construction materials.

[0064] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0065] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0066] The bio-based compatibilizers in the following embodiments are all bio-based itaconic anhydride grafted polypropylene, and the preparation method thereof includes: mixing polypropylene, itaconic anhydride, dicumyl peroxide and styrene, and melt-extruding through a twin-screw extruder to obtain bio-based itaconic anhydride grafted polypropylene; wherein the twin-screw melt extrusion adopts a screw aspect ratio of 42:1, an extrusion temperature of 160°C to 185°C, a screw speed of 200 rpm, a homogenization time of 2 to 4 hours, and a discharge temperature below 40°C; the weight ratio of the polypropylene, itaconic anhydride, dicumyl peroxide and styrene is 150:100:0.2:0.2.

[0067] Example 1

[0068] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 10 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0069] Weigh each raw material by weight, and evenly mix 96 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0070] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 703g / min, the main engine speed is 300rpm, and the side feeding speed is 53g / min.

[0071] Example 2

[0072] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0073] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0074] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 432g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0075] Example 3

[0076] The plant fiber masterbatch was prepared as follows: 150 parts of coconut fiber, 100 parts of polypropylene, and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 60 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0077] Weigh each raw material by weight, and evenly mix 76 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0078] Wherein, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 420g / min, the main engine speed is 300rpm, and the side feeding speed is 240g / min.

[0079] Example 4

[0080] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0081] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 5 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0082] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 370g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0083] Example 5

[0084] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0085] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 30 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0086] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 474g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0087] Example 6

[0088] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0089] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 6 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0090] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 432g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0091] Example 7

[0092] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0093] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 5 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0094] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 424g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0095] Example 8

[0096] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0097] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent EPDM, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0098] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 370g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0099] Example 9

[0100] The plant fiber masterbatch was prepared according to the following method: 150 parts by weight of red pine fiber, 100 parts of polypropylene, and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed, and a GELIMAT high-efficiency blending system was selected. During the high-speed operation of the machine, heat was quickly generated to quickly and uniformly mix the plant fiber and polypropylene material in a molten state. The plant fiber masterbatch was then pelletized using a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours.

[0101] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of bio-based compatibilizer, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0102] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 432g / min, the main engine speed is 300rpm, and the side feeding speed is 70g / min.

[0103] Comparative Example 1

[0104] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0105] Weigh each raw material by weight and evenly mix 92 parts of polypropylene, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and for 4 hours to obtain the plant fiber composite polypropylene material;

[0106] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 324g / min, the main engine speed is 300rpm, and the side feeding speed is 70g / min.

[0107] Comparative Example 2

[0108] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0109] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0110] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 407g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0111] Comparative Example 3

[0112] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0113] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 20 parts of high-efficiency toughening agent SEBS, 3 parts of polypropylene grafted maleic anhydride, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0114] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 432g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0115] Comparative Example 4

[0116] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0117] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 3 parts of flexible plasticizer ESO, 3 parts of PP-g-ITA, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0118] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 356g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0119] Comparative Example 5

[0120] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0121] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 20 parts of high-efficiency toughening agent SEBS, 3 parts of PP-g-ITA, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0122] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 390g / min, the main engine speed is 300rpm, and the side feeding speed is 72g / min.

[0123] Comparative Example 6

[0124] The plant fiber masterbatch was prepared according to the following method: 150 parts of coconut fiber, 100 parts of polypropylene and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed according to parts by mass; a GELIMAT high-efficiency blending system was selected to rapidly generate heat during high-speed operation of the machine, so that the plant fiber and polypropylene material were uniformly mixed in a molten state; and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch were dried in an oven at a drying temperature of 120° C. for 2 hours;

[0125] Weigh each raw material by weight, and evenly mix 92 parts of polypropylene, 20 parts of high-efficiency toughening agent SEBS, 3 parts of flexible plasticizer ESO, 20 parts of coconut masterbatch, 3 parts of PP-g-ITA, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, and 0.4 parts of lubricant PE wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0126] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 160°C, the temperature of zone 2 is 180°C, the temperature of zone 3 is 190°C, the temperature of zone 4 is 190°C, the temperature of zone 5 is 180°C, the temperature of zone 6 is 170°C, the temperature of zone 7 is 170°C, the temperature of zone 8 is 170°C, the temperature of zone 9 is 165°C, the temperature of zone 10 is 160°C, the temperature of zone 11 is 160°C, the head temperature is 160°C, the feeding rate is 500g / min, and the main engine speed is 300rpm.

[0127] The reason why the feed rate and side feed rate in Comparative Examples 1-6 of the present invention are different from those in Example 2 is because the ratio of the masterbatch to the other components of the formulation is controlled by the side feed and main feed rates.

[0128] Table 1 Plant fiber composite polypropylene material embodiment and comparative example formula and performance test data table

[0129]

[0130]

[0131] Performance characterization: Figure 1a-Figure 1b This is an SEM image of the coconut fiber composite polypropylene material prepared in Comparative Example 2 of the present invention; Figure 2a-2b is a SEM image of the coconut fiber composite polypropylene material prepared in Example 1 of the present invention;

[0132] from Figure 1a-Figure 1b 、 Figure 2a-2b In Comparative Example 2, there was a 1.2 μm gap between the two components of the composite material, while the two components of the composite material with 3 parts of the bio-based compatibilizer were tightly connected, with almost no gap between them. This shows that the addition of the bio-based compatibilizer PP-g-ITA significantly improved the interfacial compatibility between plant fibers (using coconut fiber as a typical example, but not limited to coconut fiber) and the polypropylene substrate.

[0133] From the impact strength data of comparative example 2, comparative example 3 and embodiment 2, it can be seen that the addition of PP-g-ITA comprehensively improves the room temperature and low temperature notched impact strength of the plant fiber composite material, with an improvement of about 20%.

[0134] Comparing Comparative Examples 1, 4 and 5, it is found that the addition of SEBS alone can significantly improve the normal temperature impact and low temperature impact.

[0135] Comparing Example 1 with Example 2, it is found that the addition of PP-g-ITA, as well as the synergistic effect of the flexible plasticizer ESO and the high-efficiency toughening agent SEBS, greatly improves the impact strength of the material, especially the low-temperature impact strength, from 4.1KJ / m 2Increased to 17.8KJ / m 2 The improvement is as high as over 300%.

[0136] Comparison of Example 2 and Comparative Example 6 shows that the addition of coconut masterbatch to the main feed and the side feed of coconut masterbatch not only retains the filamentous appearance of coconut fiber to a greater extent, but also significantly improves the room temperature and low temperature impact strength of the composite material. This is mainly because the side feed of coconut masterbatch greatly reduces the strong shearing of coconut fiber by the twin screw, retains the original filament morphology of coconut long fiber to a greater extent, and reduces the degradation of coconut fiber.

[0137] Combined with Examples 1 to 9, it is further demonstrated that whether the addition of PP-g-ITA is appropriately increased, or the addition of the flexible plasticizer ESO and the high-efficiency toughening agent SEBS is appropriately increased, both room temperature and low temperature impact strength of the plant fiber composite can be effectively improved, and the low temperature impact improvement is even better than that of traditional EPDM (comparison between Examples 2 and 8). At the same time, in addition to coconut fiber, for example, Korean pine fiber (Example 9), but not limited to these two plant fibers, can also be used to improve toughness using the present invention.

[0138] Example 10

[0139] The plant fiber masterbatch was prepared as follows: 150 parts by weight of jute fiber, 150 parts of polypropylene, and 0.2 parts of antioxidant 168 and 0.2 parts of antioxidant 1010 were uniformly mixed, and a GELIMAT high-efficiency blending system was selected. The machine generated heat quickly during high-speed operation to quickly and uniformly mix the plant fiber and polypropylene materials in a molten state. The plant fiber masterbatch was then pelletized using a single-screw extruder to obtain the plant fiber masterbatch; 20 parts of the prepared coconut fiber masterbatch was dried in an oven at a drying temperature of 120° C. for 2 hours.

[0140] Weigh each raw material by weight, and evenly mix 95 parts of polypropylene, 6 parts of flexible plasticizer ESO, 30 parts of high-efficiency toughening agent SEBS, 6 parts of bio-based compatibilizer, 0.3 parts of antioxidant 1010, and 0.6 parts of lubricant oxidized polyethylene wax; add the evenly mixed raw materials to a twin-screw extruder through a main feed port; add the dried plant fiber masterbatch to the twin-screw extruder through a side feed port; after extrusion granulation, dry the particles at 100° C. and 4 hours to obtain the plant fiber composite polypropylene material;

[0141] Among them, the parameters of the twin-screw extruder are set as follows: the temperature of zone 1 is 170°C, the temperature of zone 2 is 185°C, the temperature of zone 3 is 195°C, the temperature of zone 4 is 195°C, the temperature of zone 5 is 185°C, the temperature of zone 6 is 175°C, the temperature of zone 7 is 175°C, the temperature of zone 8 is 175°C, the temperature of zone 9 is 170°C, the temperature of zone 10 is 170°C, the temperature of zone 11 is 170°C, the head temperature is 170°C, the feeding rate is 703g / min, the main engine speed is 300rpm, and the side feeding speed is 59.1g / min.

[0142] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments using other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0143] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical variations made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the scope of protection of the present invention.

Claims

1. A plant fiber composite polypropylene material, characterized in that: The raw materials of the plant fiber composite polypropylene material include the following components calculated by weight: 76-96 parts of polypropylene, 10-60 parts of plant fiber masterbatch, 3-6 parts of bio-based compatibilizer, 3-6 parts of flexible plasticizer, 5-30 parts of high-efficiency toughening agent, 0.1-0.4 parts of antioxidant and 0.2-0.6 parts of lubricant; Wherein, the bio-based compatibilizer is selected from bio-based itaconic anhydride grafted polypropylene; the flexible plasticizer is epoxidized soybean oil; the high-efficiency toughening agent is hydrogenated styrene-butadiene block copolymer; The preparation method of the bio-based itaconic anhydride grafted polypropylene includes: mixing polypropylene, itaconic anhydride, dicumyl peroxide and styrene, and melt-extruded through a twin-screw extruder to obtain the bio-based itaconic anhydride grafted polypropylene; wherein the twin-screw melt extrusion adopts a screw length-to-diameter ratio of 42-52:1, an extrusion temperature of 160°C to 185°C, a screw speed of 200-400 rpm, a homogenization time of 2-4 hours, and a discharge temperature below 40°C; the weight ratio of the polypropylene, itaconic anhydride, dicumyl peroxide and styrene is 100:3-5:0.4-0.8:0.1-0.3; the itaconic anhydride is selected from all-bio-based itaconic anhydride, and the itaconic anhydride is obtained by hydrolyzing starch and fermenting it with Aspergillus terreus.

2. The plant fiber composite polypropylene material according to claim 1, characterized in that: The polypropylene is selected from homopolymer polypropylene and / or block copolymer polypropylene; the melt index of the polypropylene is 10-60 g / 10 min, 230° C., 2.16 kg.

3. The plant fiber composite polypropylene material according to claim 1, characterized in that: The plant fiber masterbatch is prepared by reacting plant fiber, polypropylene, antioxidant 168 and antioxidant 1010; the plant fiber is selected from any one or more combinations of coconut fiber, straw fiber, red pine fiber, rice husk fiber, jute fiber and wheat straw fiber.

4. The plant fiber composite polypropylene material according to claim 3, characterized in that: The total amount of polypropylene contained in the raw materials of the plant fiber composite polypropylene material is 100 parts by weight.

5. The plant fiber composite polypropylene material according to claim 1, characterized in that: The antioxidant is selected from any one or more combinations of antioxidant 1010, antioxidant 168, antioxidant 264, antioxidant 1076, antioxidant 1330, and antioxidant TBHQ; And / or, the lubricant is selected from stearates and / or wax compounds; the stearates are selected from any one or more combinations of zinc stearate, magnesium stearate, and calcium stearate; and the wax compounds are selected from polyethylene wax and / or oxidized polyethylene wax.

6. The method for preparing a plant fiber composite polypropylene material according to any one of claims 1 to 5, characterized in that: include: Polypropylene, bio-based compatibilizer, flexible plasticizer, high-efficiency toughening agent, antioxidant and lubricant are mixed evenly and added to a twin-screw extruder through a main feed port. At the same time, plant fiber masterbatch is added to the twin-screw extruder through a side feed port, and then melt-extruded and granulated to obtain the plant fiber composite polypropylene material.

7. The preparation method according to claim 6, characterized in that The process parameters adopted by the twin-screw extruder include: zone one temperature of 160-170°C, zone two temperature of 175-185°C, zone three temperature of 185-195°C, zone four temperature of 185-195°C, zone five temperature of 175-185°C, zone six temperature of 165-175°C, zone seven temperature of 165-175°C, zone eight temperature of 165-175°C, zone nine temperature of 160-170°C, zone ten temperature of 160-170°C, zone eleven temperature of 160-170°C, die head temperature of 160-170°C, feeding speed of 10-30kg / h, main engine speed of 200-500rpm, and side feeding speed of 0.5-24kg / h.

8. The preparation method according to claim 6, characterized in that Also includes: The plant fiber, polypropylene, antioxidant 168 and antioxidant 1010 are melt-mixed, and then granulated by a single-screw extruder to obtain the plant fiber masterbatch; The weight ratio of the plant fiber, polypropylene, antioxidant 168 and antioxidant 1010 is 150:100-150:0.1-0.4:0.1-0.

4.

9. The preparation method according to claim 6, characterized in that Also includes: The product obtained by the melt extrusion granulation process is dried at a temperature of 90-110° C. for 3-6 hours.

10. Use of the plant fiber composite polypropylene material according to any one of claims 1 to 5 in preparing a -20°C low-temperature resistant and high-impact composite material.

Images