Long glass fiber reinforced polypropylene composite material and preparation method thereof

Abstract

The invention discloses a long glass fiber reinforced polypropylene composite material which is prepared from the following components in parts by weight: 70-80 parts of polypropylene resin, 20-40 parts of continuous glass fiber, 2-5 parts of a compatilizer, 0.5-1 part of graphene oxide, 0.2 part of a nucleating agent and 1 part of a processing aid. A trace amount of graphene oxide and the nucleating agent are adopted and have a synergistic effect, the graphene oxide improves the heat conductivity coefficient of the material, and meanwhile, the nucleating agent improves the crystallization rate and refines the grain size, so that a skin layer and a core layer of the polypropylene composite material are uniformly heated and rapidly crystallized in the cooling process, and generation of internal stress of the material is reduced; therefore, the warping rate of the long glass fiber reinforced polypropylene composite material is greatly reduced, and meanwhile, higher mechanical properties are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material modification, and specifically to a long glass fiber reinforced polypropylene composite material and a preparation method thereof. Background Art

[0002] Polypropylene (PP) has the advantages of low density, easy processing, excellent mechanical properties, etc., and has been widely used in the automotive industry, household appliances and machinery fields. For the automotive industry, polypropylene is mainly used in automotive interior and exterior parts, such as interior parts like instrument panels, door panels and pillars, and exterior parts like bumpers, fender liners, and air deflectors. However, pure polypropylene is limited in its application fields due to defects such as strength and dimensional stability, so it is usually filled and modified with mineral powder, fibers, etc. to achieve the purpose of reinforcement and modification, among which glass fiber filling modification is the most commonly used reinforcement and modification method at present. However, long glass fiber reinforced polypropylene resin materials also have some defects, such as high warpage curvature, which limits its further application.

[0003] Therefore, it is of great significance to develop a low warpage long glass fiber reinforced polypropylene composite material. Summary of the Invention

[0004] In view of this, the present invention provides a long glass fiber reinforced polypropylene composite material and a preparation method thereof. By adding a trace amount of graphene oxide - nucleating agent composition, the long glass fiber reinforced polypropylene composite material is given a lower warpage and maintains high mechanical properties, solving the deficiencies in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In the first aspect, the present invention discloses a long glass fiber reinforced polypropylene composite material, which is prepared from the following components according to parts by weight:

[0007]

[0008] As a further scheme of the present invention: the polypropylene resin is a high - flow polypropylene resin, and the melt mass - flow rate at 230°C and 2.16 kg is 30 - 150 g / 10 min.

[0009] As a further scheme of the present invention: the compatibilizer is at least one of maleic anhydride grafted polypropylene and maleic anhydride grafted POE elastomer.

[0010] As a further scheme of the present invention: the nucleating agent is an α - nucleating agent.

[0011] As a further embodiment of the present invention: the nucleating agent is at least one of dimethicone sorbitol and its derivatives, aromatic phosphate nucleating agents, substituted benzoate nucleating agents, carboxylic acid metal salt nucleating agents and sorbitol benzyl derivatives.

[0012] As a further solution of the present invention: the processing aid is at least one of a lubricant, an antioxidant, a light absorber and a light stabilizer.

[0013] In a second aspect, the present invention discloses a method for preparing the long glass fiber reinforced polypropylene composite material, comprising the following steps:

[0014] Weighing polypropylene resin, compatibilizer, graphene oxide, nucleating agent and processing aid according to weight parts and mixing them thoroughly to obtain a premix;

[0015] The premix is ​​added into the main feed port of a twin-screw extruder, and continuous glass fibers are added from the impregnation die head of the twin-screw extruder. After melt blending and granulation, a long glass fiber reinforced polypropylene composite material is obtained.

[0016] As a further solution of the present invention: the barrel temperature of the twin-screw extruder is 160°C-300°C, the mold temperature is 300-320°C, the screw speed is 250-280r / min, the melt pressure is 1.0-1.2MPa, and the vacuum degree is -0.06MPa.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] A low-warpage long glass fiber reinforced polypropylene composite material prepared by the present invention has a very high thermal conductivity by using a trace amount of graphene oxide, which can improve the thermal conductivity of polypropylene, thereby reducing the warpage problem caused by uneven heating of the polypropylene composite material during the cooling process. At the same time, the graphene oxide has a two-dimensional sheet structure, which can play a role in strengthening polypropylene, and further reduce the warpage of the polypropylene composite. The nucleating agent helps to improve the crystallization rate of the polypropylene composite material and refine the grain size, thereby improving the shrinkage deformation caused by secondary crystallization and post-crystallization after the composite material is formed, thereby reducing the warpage. The nucleating agent and graphene oxide have a synergistic effect. The graphene oxide improves the thermal conductivity of the material. At the same time, the nucleating agent improves the crystallization rate and refines the grain size, so that the skin layer and the core layer of the polypropylene composite material are evenly heated during the cooling process, and the crystallization is rapid, which reduces the generation of internal stress in the material, thereby greatly reducing the warpage of the long glass fiber reinforced polypropylene composite material, while ensuring higher mechanical properties.

[0019] The preparation process of the invention is simple and can be mass-produced. The low-warpage long glass fiber reinforced polypropylene composite material product has the characteristics of high strength, high modulus, high toughness and high thermal conductivity, and has very high commercial properties. Detailed implementation manners

[0020] For the convenience of understanding the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0022] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0023] Polypropylene resin, grade K7100, melt index 100 g / 10 min, manufacturer: Yanshan Petrochemical.

[0024] Continuous glass fiber, specification model EDR24-2400-386T, manufacturer: China National Bluestar (Group) Co., Ltd.

[0025] The compatibilizer is preferably maleic anhydride grafted polypropylene, grade: Saudi Sabic 350K, grafting rate 0.7-0.9%, manufacturer: Dongguan Shenghao Plastic Raw Materials Co., Ltd.

[0026] Graphene oxide, thickness: 0.55~1.2 nm, diameter: 0.5~3 μm, number of layers: 1-5 layers, Zhongke Leiming (Beijing) Technology Co., Ltd.

[0027] Nucleating agent, grade NX 8000k, manufacturer: Milliken & Company.

[0028] The processing aid is compounded from a lubricant, a primary antioxidant, a secondary antioxidant, a light absorber, and a light stabilizer according to a mass ratio of 10:1:1:1:1. Among them, the lubricant is a silicone masterbatch, grade MB50-002, manufacturer: Dow Corning; the primary antioxidant grade Irganox 565, manufacturer: BASF; the secondary antioxidant grade AN 168, manufacturer: Qingdao Dedat Chemical Co., Ltd.; the light absorber grade Chiguard 5050, manufacturer: Qitai Co., Ltd.; the light stabilizer grade LA-52, manufacturer: Adeka (China) Investment Co., Ltd.

[0029] All materials are commercially available conventional and commonly used products.

[0030] It is understood that the above raw materials and reagents are only examples of some specific embodiments of the present invention to make the technical solutions of the present invention clearer, and do not represent that the present invention can only use the above reagents. The specific scope is subject to the claims. In addition, the "parts" mentioned in the examples and comparative examples refer to parts by weight unless otherwise specified.

[0031] Any range described in the present invention includes the end values, any numerical value between the end values, and any sub-range composed of any numerical value between the end values or the end values.

[0032] The following Table 1 shows the PP / GF process parameters in the examples and comparative examples.

[0033] Table 1

[0034]

[0035] Example 1

[0036] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer, 0.5 part of graphene oxide, 0.2 part of nucleating agent and 1 part of processing aid and place them in a high-speed mixer and mix for 10 minutes to obtain a premix;

[0037] Add the said premix into the main feeding port of a twin-screw extruder, add continuous glass fiber into the impregnation die head of the twin-screw extruder according to the parameters in Table 1, and through extrusion granulation, a low-warpage long glass fiber reinforced polypropylene composite material is obtained.

[0038] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the temperature of the die (i.e., the impregnation die head) is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0039] Example 2

[0040] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer, 0.5 part of graphene oxide, 0.2 part of nucleating agent and 1 part of processing aid and place them in a high-speed mixer and mix for 10 minutes to obtain a premix;

[0041] Add the said premix into the main feeding port of a twin-screw extruder, add continuous glass fiber into the impregnation die head of the twin-screw extruder according to the parameters in Table 1, and through extrusion granulation, a low-warpage long glass fiber reinforced polypropylene composite material is obtained.

[0042] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0043] Example 3

[0044] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer, 0.5 part of graphene oxide, 0.2 part of nucleating agent and 1 part of processing aid and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0045] Add the premix to the main feeding port of the twin-screw extruder, add continuous glass fiber to the impregnation die head of the twin-screw extruder according to the parameters in Table 1, and through extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0046] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0047] Example 4

[0048] Weigh 75 parts of polypropylene resin, 3 parts of compatibilizer, 0.8 part of graphene oxide, 0.2 part of nucleating agent and 1 part of processing aid and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0049] Add the premix to the main feeding port of the twin-screw extruder, add continuous glass fiber to the impregnation die head of the twin-screw extruder according to the parameters in Table 1, and through extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0050] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0051] Example 5

[0052] Weigh 70 parts of polypropylene resin, 3 parts of compatibilizer, 1 part of graphene oxide, 0.2 part of nucleating agent and 1 part of processing aid and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0053] Add the premix to the main feeding port of a twin-screw extruder, and add continuous glass fibers to the impregnation die head of the twin-screw extruder according to the parameters in Table 1. After extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0054] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0055] Comparative Example 1

[0056] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer and 1 part of processing aid, and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0057] Add the premix to the main feeding port of a twin-screw extruder, and add continuous glass fibers to the impregnation die head of the twin-screw extruder according to the parameters in Table 1. After extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0058] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0059] Comparative Example 2

[0060] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer, 0.7 parts of nucleating agent and 1 part of processing aid, and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0061] Add the premix to the main feeding port of a twin-screw extruder, and add continuous glass fibers to the impregnation die head of the twin-screw extruder according to the parameters in Table 1. After extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0062] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0063] Comparative Example 3

[0064] Weigh 80 parts of polypropylene resin, 3 parts of compatibilizer, 0.7 parts of graphene oxide and 1 part of processing aid, and place them in a high-speed mixer and mix for 10 min to obtain a premix.

[0065] Add the premix to the main feed port of a twin-screw extruder, and add continuous glass fibers to the impregnation die head of the twin-screw extruder according to the parameters in Table 1. After extrusion granulation, a low-warpage long glass fiber-reinforced polypropylene composite material is obtained.

[0066] Among them, the barrel temperatures of the twin-screw extruder are 160°C in zone 1, 220°C in zone 2, 240°C in zone 3, 260°C in zone 4, 280°C in zone 5, 300°C in zone 6, the die temperature is 300°C, the screw speed is 500 r / min, the melt pressure is 1.0 MPa, and the vacuum degree is -0.06 MPa.

[0067] Test Example

[0068] Melt the long glass fiber-reinforced polypropylene composite materials prepared in Examples 1-5 and Comparative Examples 1-3 respectively in an injection molding machine, and prepare standard specimens and shrinkage plates with dimensions of 200 mm * 140 mm * 2.5 mm for warpage testing; the barrel temperature of the injection molding machine is 220°C, and the mold temperature is 60°C.

[0069] Conduct experimental tests on the standard specimens injection-molded from the long glass fiber-reinforced polypropylene composite materials prepared in Examples 1-5 and Comparative Examples 1-3, and conduct tensile property, flexural property, and impact property tests according to ISO standards. Use a caliper to measure the maximum warpage height of the flat shrinkage plate. The test results are shown in Table 1.

[0070] Table 1

[0071]

[0072] It can be seen from Table 1 that: in Comparative Example 1, the warpage size of the long glass fiber-reinforced polypropylene composite material is relatively large. In Comparative Example 2, after adding a nucleating agent, the warpage size slightly decreases. In Comparative Example 3, after adding graphene oxide, it is beneficial to the uniformity of the material, and the cooling warpage size slightly decreases. In Examples 1-5, when a trace amount of graphene oxide and a trace amount of nucleating agent are simultaneously added to the long glass fiber-reinforced polypropylene composite material, the two play a synergistic role. Graphene oxide increases the thermal conductivity of the material, and at the same time the nucleating agent improves the crystallization rate and refines the grain size, enabling the skin layer and the core layer of the polypropylene composite material to be uniformly heated during the cooling process and quickly crystallize, reducing the generation of internal stress in the material, thereby greatly reducing the warpage rate of the long glass fiber-reinforced polypropylene composite material while ensuring high mechanical properties.

[0073] Although this specification is described in terms of embodiments, not every embodiment contains only an independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0074] Therefore, the above description is only a preferred embodiment of the present application and is not used to limit the scope of implementation of the present application; that is, all equivalent transformations made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A long glass fiber reinforced polypropylene composite material, characterized in that: It is prepared from the following components in parts by weight:

2. The long glass fiber reinforced polypropylene composite material according to claim 1, characterized in that: The polypropylene resin is a high-fluidity polypropylene resin, and the melt mass flow rate under the conditions of 230° C. and 2.16 kg is 30 to 150 g / 10 min.

3. The long glass fiber reinforced polypropylene composite material according to claim 1, characterized in that: The compatibilizer is at least one of maleic anhydride grafted polypropylene and maleic anhydride grafted POE elastomer.

4. The long glass fiber reinforced polypropylene composite material according to claim 1, characterized in that: The nucleating agent is an α-nucleating agent.

5. The long glass fiber reinforced polypropylene composite material according to claim 1, characterized in that: The nucleating agent is at least one of dimethicone sorbitol and its derivatives, aromatic phosphate ester nucleating agents, substituted benzoate nucleating agents, carboxylic acid metal salt nucleating agents and sorbitol benzyl derivatives.

6. The long glass fiber reinforced polypropylene composite material according to claim 1, characterized in that: The processing aid is at least one of a lubricant, an antioxidant, a light absorber and a light stabilizer.

7. The method for preparing the long glass fiber reinforced polypropylene composite material according to any one of claims 1 to 6, characterized in that: The following steps are involved: Weighing polypropylene resin, compatibilizer, graphene oxide, nucleating agent and processing aid according to weight parts and mixing them thoroughly to obtain a premix; The premix is ​​added into the main feed port of a twin-screw extruder, and continuous glass fibers are added from the impregnation die head of the twin-screw extruder. After melt blending and granulation, a long glass fiber reinforced polypropylene composite material is obtained.

8. The preparation method according to claim 7, characterized in that: The barrel temperature of the twin-screw extruder is 160-300°C, the mold temperature is 300-320°C, the screw speed is 250-280r / min, the melt pressure is 1.0-1.2MPa, and the vacuum degree is -0.06MPa.

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