Amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna housing and preparation method thereof

Abstract

The invention discloses an amino POSS (Polyhedral Oligomeric Silsesquioxane) nano-modified polypropylene glass fiber composite material for a 5G antenna housing and a preparation method thereof, and relates to the technical field of polypropylene glass fiber composite materials. Through molecular structure design, an amino POSS nano material is grafted to a polypropylene glass fiber composite material by adopting a melt grafting method, so that the problem that nano particles are difficult to disperse in a polymer melt extrusion process is solved. And by using an amino POSS nano material melt grafting modification method, the dielectric constant of the polypropylene glass fiber composite material is effectively reduced, and the comprehensive performance of the polypropylene glass fiber composite material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polypropylene glass fiber composites, and particularly to an amino-POSS nano-modified polypropylene glass fiber composite for a 5G radome and a preparation method thereof. Background Art

[0002] The rapid development of 5G communication technology has brought new opportunities and challenges to wireless communication. As a key component of 5G base station antennas, the material properties of the radome directly affect the coverage range, transmission rate, and signal quality of the 5G communication network. The dielectric constant has a great influence on the signal transmission speed, signal delay, signal loss, etc. of 5G communication millimeter waves. The introduction of millimeter waves has put forward higher performance requirements for the high-transmission dielectric materials of related terminal device components, requiring the related dielectric materials to have the characteristics of stable and low dielectric loss and dielectric constant at higher frequencies, so as to achieve the purpose of maximum transmission and minimum loss when high-frequency millimeter wave signals pass through the related component materials; at the same time, the radome needs to withstand the impact of rain, snow, wind, sand and the test of harsh environments such as high and low temperatures outdoors, and requires the material to have comprehensive properties such as high strength and high and low temperature impact resistance.

[0003] Polypropylene (PP) has excellent insulation performance and mechanical properties and a low dielectric constant, and is very suitable for manufacturing base station radomes. However, the application of polypropylene is limited due to its defects such as poor balance between rigidity and toughness and large shrinkage rate of parts, and polypropylene needs to be modified. Glass fiber reinforced polypropylene is a composite material with excellent comprehensive properties and is considered to be one of the ideal materials for preparing 5G radomes. However, the addition of ordinary E glass fiber will increase the dielectric constant of the material. Therefore, low-dielectric D glass fiber can be used to reduce the dielectric constant of the material, but low-dielectric D glass fiber has problems such as high cost and poor stability, and its application is not yet mature. At the same time, in the era of 5G communication, the performance requirements of radome materials are more stringent, and the mechanical properties of general short glass fiber reinforced polypropylene are difficult to meet the stringent requirements of 5G communication for radomes. Using long glass fiber reinforced polypropylene also has problems such as glass fiber exposure, poor dimensional stability, and poor low-temperature resistance. Therefore, there is an urgent need to develop a low-dielectric glass fiber reinforced polypropylene material with excellent comprehensive properties.

[0004] Cage-like polyhedral oligomeric silsesquioxane (POSS) has a molecular size of 1-3 nm and a microporous structure with a pore size of 0.5 nm. It is a kind of compound with nano-molecular size and organic-inorganic hybrid structure. Due to its unique physical and chemical properties, when applied to polymer modification, it can not only improve the thermal performance and strength of organic-inorganic hybrid materials, but also reduce the dielectric constant of polymers. However, like other nanomaterials, POSS is very easy to aggregate, and it is very difficult to be well dispersed in the polymer matrix by melt processing methods, resulting in its modification effect falling short of expectations.

[0005] Therefore, it is an urgent problem to be solved how to apply POSS well to glass fiber reinforced polypropylene materials to reduce the dielectric constant of glass fiber reinforced polypropylene materials. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an amino-POSS nano-modified polypropylene glass fiber composite material for 5G antenna covers and its preparation method. Through molecular structure design, the amino-POSS nano-material is grafted onto the polypropylene glass fiber composite material by a melt grafting method, solving the problem of difficult dispersion of nano-particles during the melt extrusion process of polymers. By using the melt grafting modification method of amino-POSS nano-materials, the dielectric constant of the polypropylene glass fiber composite material is effectively reduced, and the comprehensive performance of the polypropylene glass fiber composite material is improved.

[0007] The technical solution of the present invention is as follows:

[0008] On the one hand, the present invention provides a preparation method of an amino-POSS nano-modified polypropylene glass fiber composite material for 5G antenna covers, including the following steps:

[0009] S1: 70-90 parts of maleic anhydride grafted polyolefin resin, 10-20 parts of amino-POSS nano-composite, 3-5 parts of nano-silica composition and 0.8-1.5 parts of processing aid are respectively added to a twin-screw extruder through a weighing scale, and are subjected to reactive extrusion, granulation and drying through the twin-screw extruder to obtain an amino-POSS grafted polyolefin masterbatch;

[0010] S2: 30-70 parts of polypropylene resin, 10-20 parts of amino-POSS grafted polyolefin masterbatch, 5-10 parts of toughening agent, 0.3-0.8 parts of light stabilizer, 0.8-1.5 parts of processing aid are added to the twin-screw extruder from the main feeding port of the twin-screw extruder, and 20-40 parts of glass fiber are added to the twin-screw extruder from the side feeding port. Through the twin-screw extruder, melt blending reaction, extrusion, strand drawing, cooling, pelletizing and drying are carried out to obtain an amino-POSS nano-modified polypropylene glass fiber composite material for 5G antenna covers; in steps S1 and S2, the addition amounts of the respective raw materials are in parts by weight.

[0011] Preferably, in step S1, the maleic anhydride grafted polyolefin resin is maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted polyolefin elastomer POE (POE-g-MAH) with a mass ratio of (2-4):1.

[0012] Preferably, in step S1, the amino-POSS nano-composite is 3-aminopropyl POSS and octakis(3-aminopropyl) POSS with a mass ratio of (3-4):1.

[0013] Preferably, in step S1, the nano-silica composition is nano-silica, titanium dioxide and wollastonite with a mass ratio of (1-2):(2-3):1.

[0014] Preferably, in step S1, the twin-screw extruder is a co-rotating twin-screw extruder with a screw length-diameter ratio of (48-52):1, a feeding section temperature of 120-160 °C, a plasticizing section temperature of 150-180 °C, a homogenizing section temperature of 160-190 °C, a head temperature of 180-190 °C, a screw speed of 100-300 rmp, and a pressure of 3-6 MPa.

[0015] Preferably, in step S2, the toughening agent is at least one of ethylene-vinyl acetate copolymer (EVA), ethylene-butyl acrylate copolymer (EBA), ethylene-methyl acrylate copolymer (EMA), ethylene propylene diene monomer (EPDM), and ethylene-α-olefin copolymer (POE).

[0016] Preferably, in step S2, the light stabilizer is at least one of benzophenone weathering agent UV-531, benzotriazole weathering agent UV-326, hindered amine light stabilizer UV-770, and UV-3808PP5.

[0017] Preferably, in step S2, the twin-screw extruder is a co-rotating twin-screw extruder with a screw length-diameter ratio of (40-48):1, a feeding section temperature of 130-170 °C, a plasticizing section temperature of 150-190 °C, a homogenizing section temperature of 160-200 °C, a head temperature of 190-210 °C, a screw speed of 200-600 rmp, and a pressure of 6-10 MPa.

[0018] Preferably, the processing aids include lubricants and antioxidants, where the lubricants are one or more of silicone powder, white oil, polyethylene wax, ethylene bis-stearamide (EBS), and pentaerythritol stearate; the antioxidants are at least two of antioxidant 1010, antioxidant 1076, antioxidant 168, and distearyl thiodipropionate (DSTP).

[0019] Preferably, the processing aids are a composition of lubricant EBS, antioxidant 1010, and antioxidant 168 with a mass ratio of (2-3):1:1.

[0020] On the other hand, the present invention provides an amino-POSS nano-modified polypropylene glass fiber composite for 5G radomes, which is prepared by the preparation method of the amino-POSS nano-modified polypropylene glass fiber composite for 5G radomes described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. In terms of molecular structure design, the present invention adopts the method of melt chemical grafting to graft the amino POSS nanocomposite onto polyolefin. During the grafting process, octakis(3-aminopropyl) POSS in the amino POSS nanocomposite undergoes a chemical reaction with maleic anhydride in maleic anhydride-grafted polyolefin through eight amino arms simultaneously, generating micro-crosslinking; while 3-aminopropyl POSS is grafted onto the main chain of maleic anhydride-grafted polyolefin through a single-arm amino group, obtaining POSS side-chain grafted polyolefin. The grafting of POSS on the polyolefin side chain and the above-mentioned micro-crosslinked POSS achieve a highly dispersed state of amino POSS nanoparticles at the molecular level in the polymer matrix; meanwhile, the grafting of POSS on the polyolefin side chain and the above-mentioned micro-crosslinking technology synergistically increase the free volume of the polyolefin molecular chain. The microporous structure of the amino POSS nanocomposite itself and the increase in the free volume of the polyolefin molecular side chain together reduce the dielectric constant and dielectric loss of the polypropylene glass fiber composite.

[0023] 2. In the present invention, the nano-silica composition has good affinity with the amino POSS nanocomposite. Therefore, after grafting the amino POSS nanocomposite onto polyolefin, the aggregation problem of the amino POSS nanocomposite and the nano-silica composition during the melt processing of polypropylene is also solved, providing an effective method for polymer modification of nanomaterials. At the same time, the highly dispersed nano-silica composition and amino POSS nanocomposite act as nucleating agents and toughening agents. The synergistic effect of the two greatly improves the comprehensive performance of the polypropylene glass fiber composite, making it have a low dielectric constant, low dielectric loss, and high and low temperature impact strength, meeting the stringent requirements of materials for components such as 5G communication antenna covers, and contributing to the rapid development of the 5G communication field. Detailed Embodiments

[0024] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0025] The raw materials used in the following examples and comparative examples are all commercially available products unless otherwise specified.

[0026] PP-g-MAH: CMG9801, grafting rate 1.5%, Jiayirong Polymer (Shanghai) Co., Ltd.;

[0027] POE-g-MAH: CMG5805, grafting rate 1.2%, Jiayirong Polymer (Shanghai) Co., Ltd.;

[0028] Toughening agent: POE 8842, EPDM 4640, Dow Chemical;

[0029] Lubricant: EBS P130, Kao Corporation, Japan;

[0030] Antioxidant: Antioxidant 1010, Antioxidant 168, BASF Corporation;

[0031] Amino POSS: 3-aminopropyl POSS, octakis(3-aminopropyl) POSS, Hybrid Plastics Inc., USA;

[0032] Glass fiber: HMG538-10-4.5, Taishan Fiberglass Co., Ltd.;

[0033] Light stabilizer: UV-3808PP5, Solvay Group;

[0034] Polypropylene resin: M60T, Zhenhai Refining & Chemical Co., Ltd., SINOPEC; SP179, Lanzhou Petrochemical Company, PetroChina.

[0035] Example 1

[0036] The preparation method of the amino POSS nano-modified polypropylene glass fiber composite material for 5G radome in this example includes the following steps:

[0037] S1 Preparation of amino POSS grafted polyolefin masterbatch: 86.2 parts of maleic anhydride grafted polyolefin resin, 10 parts of amino POSS nano-complex, 3 parts of nano-silica composition and 0.8 parts of processing aid are respectively added into a co-rotating twin-screw extruder through a weighing scale. The maleic anhydride grafted polyolefin resin is a mixture of PP-g-MAH and POE-g-MAH with a mass ratio of 2:1. The amino POSS nano-complex is a mixture of 3-aminopropyl POSS and octakis(3-aminopropyl) POSS with a mass ratio of 3:1. The nano-silica composition is a mixture of nano-silica, titanium dioxide and wollastonite with a mass ratio of 1:2:1. The processing aid is a mixture of EBS P130, Antioxidant 1010 and Antioxidant 168 with a mass ratio of 2:1:1. The length-diameter ratio of the screw of the co-rotating twin-screw extruder is 48:1. Under the transportation, shearing and mixing of the co-rotating twin-screw extruder, they are fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are as follows: the temperature of the feeding section is 120°C, 140°C, 160°C; the temperature of the plasticizing section is 170°C, 180°C, 180°C; the temperature of the homogenizing section is 180°C, 185°C, 185°C, 185°C, 190°C, 190°C; the temperature of the head is 190°C; the screw speed is 200 rmp and the pressure is 4 MPa. Subsequently, it is subjected to reactive extrusion, pelletizing and drying to obtain the amino POSS grafted polyolefin masterbatch;

[0038] S2 Preparation of Amino-POSS Nano-Modified Polypropylene Glass Fiber Composite for 5G Radome: 63.9 parts of polypropylene resin, 10 parts of amino-POSS grafted polyolefin masterbatch, 5 parts of toughening agent POE 8842, 0.3 part of light stabilizer UV-3808PP5, and 0.8 part of processing aid were added to the co-rotating twin-screw extruder from the main feeding port, and 20 parts of glass fiber were added from the side feeding port of the co-rotating twin-screw extruder. The processing aid was EBS P130, antioxidant 1010, and antioxidant 168 with a mass ratio of 2:1:1. The length-diameter ratio of the screws of the co-rotating twin-screw extruder was 40:1. Under the conveying, shearing, and mixing of the co-rotating twin-screw extruder, they were fully melted and mixed, and then extruded through the die head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder were as follows: the temperature of the feeding section was 130°C, 160°C, 180°C; the temperature of the plasticizing section was 180°C, 190°C, 190°C; the temperature of the homogenizing section was 190°C, 195°C, 195°C, 195°C, 200°C, 200°C; the temperature of the die head was 205°C; the screw speed was 300 rmp, and the pressure was 8 MPa. Subsequently, it was subjected to strand drawing, cooling, pelletizing, and drying to obtain an amino-POSS nano-modified polypropylene glass fiber composite for 5G radome with a glass fiber content of 20 wt.%.

[0039] Example 2

[0040] The preparation method of the amino-POSS nano-modified polypropylene glass fiber composite for 5G radome in this example includes the following steps:

[0041] S1 Preparation of amino-POSS grafted polyolefin masterbatch: 80 parts of maleic anhydride grafted polyolefin resin, 15 parts of amino-POSS nanocomposite, 4 parts of nano-silica composition and 1 part of processing aid were respectively added into a co-rotating twin-screw extruder through a weighing scale. The maleic anhydride grafted polyolefin resin was a mixture of PP-g-MAH and POE-g-MAH with a mass ratio of 3:1. The amino-POSS nanocomposite was a mixture of 3-aminopropyl POSS and octakis(3-aminopropyl) POSS with a mass ratio of 4:1. The nano-silica composition was a mixture of nano-silica, titanium dioxide and wollastonite with a mass ratio of 2:2:1. The processing aid was a mixture of EBS P130, antioxidant 1010 and antioxidant 168 with a mass ratio of 3:1:1. The length-diameter ratio of the screw of the co-rotating twin-screw extruder was 48:1. Under the transportation, shearing and mixing of the co-rotating twin-screw extruder, they were fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder were as follows: the temperature of the feeding section was 120 °C, 140 °C, 160 °C; the temperature of the plasticizing section was 170 °C, 180 °C, 180 °C; the temperature of the homogenizing section was 180 °C, 185 °C, 185 °C, 185 °C, 190 °C, 190 °C; the temperature of the head was 190 °C; the screw speed was 300 rmp and the pressure was 3 MPa. Subsequently, through reactive extrusion, pelletizing and drying, the amino-POSS grafted polyolefin masterbatch was obtained.

[0042] S2 Preparation of amino-POSS nano-modified polypropylene glass fiber composite for 5G radome: 48.5 parts of polypropylene resin, 20 parts of amino-POSS grafted polyolefin masterbatch, 10 parts of toughening agent EPDM 4640, 0.5 part of light stabilizer UV-531, 1 part of processing aid were added into a co-rotating twin-screw extruder from the main feeding port, and 20 parts of glass fiber were added from the side feeding port of the co-rotating twin-screw extruder. The processing aid was a mixture of EBS P130, antioxidant 1010 and antioxidant 168 with a mass ratio of 3:1:1. The length-diameter ratio of the screw of the co-rotating twin-screw extruder was 44:1. Under the transportation, shearing and mixing of the co-rotating twin-screw extruder, they were fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder were as follows: the temperature of the feeding section was 130 °C, 160 °C, 170 °C; the temperature of the plasticizing section was 180 °C, 190 °C, 190 °C; the temperature of the homogenizing section was 190 °C, 195 °C, 195 °C, 195 °C, 200 °C, 200 °C; the temperature of the head was 205 °C; the screw speed was 500 rmp and the pressure was 6 MPa. Subsequently, through strand drawing, cooling, pelletizing and drying, the amino-POSS nano-modified polypropylene glass fiber composite for 5G radome with a glass fiber content of 20 wt.% was obtained.

[0043] Example 3

[0044] Preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G radome of this embodiment, comprising the following steps:

[0045] S1 Preparation of amino POSS grafted polyolefin masterbatch: 73.5 parts of maleic anhydride grafted polyolefin resin, 20 parts of amino POSS nano-composite, 5 parts of nano-silica composition and 1.5 parts of processing aid are respectively added into a co-rotating twin-screw extruder through a weighing scale. The maleic anhydride grafted polyolefin resin is a mixture of PP-g-MAH and POE-g-MAH with a mass ratio of 4:1. The amino POSS nano-composite is a mixture of 3-aminopropyl POSS and octa(3-aminopropyl) POSS with a mass ratio of 3.5:1. The nano-silica composition is a mixture of nano-silica, titanium dioxide and wollastonite with a mass ratio of 2:3:1. The processing aid is a mixture of EBS P130, antioxidant 1010 and antioxidant 168 with a mass ratio of 2:1:1. The length-diameter ratio of the screw of the co-rotating twin-screw extruder is 52:1. Under the conveying, shearing and mixing of the co-rotating twin-screw extruder, they are fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are: the temperature of the feeding section is 120 °C, 140 °C, 160 °C; the temperature of the plasticizing section is 170 °C, 180 °C, 180 °C; the temperature of the homogenizing section is 180 °C, 185 °C, 185 °C, 185 °C, 190 °C, 190 °C; the temperature of the head is 190 °C; the screw speed is 100 rmp and the pressure is 5 MPa. Subsequently, through reactive extrusion, pelletizing and drying, amino POSS grafted polyolefin masterbatch is obtained;

[0046] S2 Preparation of amino POSS nano-modified polypropylene glass fiber composite material for 5G radome: 42.7 parts of polypropylene resin, 15 parts of amino POSS grafted polyolefin masterbatch, 10 parts of toughening agent POE8842, 0.8 part of light stabilizer UV-326 and 1.5 parts of processing aid are added into the co-rotating twin-screw extruder from the main feeding port of the co-rotating twin-screw extruder, and 30 parts of glass fiber are added into the co-rotating twin-screw extruder from the side feeding port. The processing aid is a mixture of EBS P130, antioxidant 1010 and antioxidant 168 with a mass ratio of 3:1:1. The length-diameter ratio of the screw of the co-rotating twin-screw extruder is 48:1. Under the conveying, shearing and mixing of the co-rotating twin-screw extruder, they are fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are: the temperature of the feeding section is 130 °C, 160 °C, 170 °C; the temperature of the plasticizing section is 180 °C, 190 °C, 190 °C; the temperature of the homogenizing section is 190 °C, 195 °C, 195 °C, 195 °C, 200 °C, 200 °C; the temperature of the head is 205 °C; the screw speed is 400 rmp and the pressure is 7 MPa. Subsequently, through strand drawing, cooling, pelletizing and drying, amino POSS nano-modified polypropylene glass fiber composite material for 5G radome with a glass fiber content of 20 wt.% is obtained.

[0047] Example 4

[0048] The preparation method of the amino-POSS nano-modified polypropylene glass fiber composite material for the 5G radome of this example includes the following steps:

[0049] S1 Prepare the amino-POSS grafted polyolefin masterbatch: the same as step S1 of Example 3;

[0050] S2 Prepare the amino-POSS nano-modified polypropylene glass fiber composite material for the 5G radome: Add 38.5 parts of polypropylene resin, 20 parts of amino-POSS grafted polyolefin masterbatch, 10 parts of toughening agent POE8842, 0.5 part of light stabilizer UV-770, 1 part of processing aid from the main feeding port of the co-rotating twin-screw extruder, and 30 parts of glass fiber from the side feeding port of the co-rotating twin-screw extruder into the co-rotating twin-screw extruder. The processing aid is EBS P130, antioxidant 1010 and antioxidant 168 with a mass ratio of 3:1:1; the length-diameter ratio of the screw of the co-rotating twin-screw extruder is 48:1. Under the transportation, shearing and mixing of the co-rotating twin-screw extruder, it is fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are: the temperature of the feeding section is 130 °C, 160 °C, 170 °C; the temperature of the plasticizing section is 180 °C, 190 °C, 190 °C; the temperature of the homogenizing section is 190 °C, 195 °C, 195 °C, 195 °C, 200 °C, 200 °C; the temperature of the head is 205 °C; the screw speed is 300 rmp, and the pressure is 8 MPa; then it is subjected to strand drawing, cooling, pelletizing and drying to obtain the amino-POSS nano-modified polypropylene glass fiber composite material for the 5G radome with a glass fiber content of 30 wt.%.

[0051] Example 5

[0052] The preparation method of the amino-POSS nano-modified polypropylene glass fiber composite material for the 5G radome of this example includes the following steps:

[0053] S1 Prepare the amino-POSS grafted polyolefin masterbatch: the same as step S1 of Example 3;

[0054] S2 Preparation of Amino-POSS Nano-Modified Polypropylene Glass Fiber Composite Material for 5G Antenna Radome: Add 33.5 parts of polypropylene resin, 20 parts of amino-POSS grafted polyolefin masterbatch, 5 parts of toughening agent POE8842, 0.5 part of light stabilizer UV-3808PP5, and 1 part of processing aid into the co-rotating twin-screw extruder from the main feeding port, and add 40 parts of glass fiber into the co-rotating twin-screw extruder from the side feeding port. The processing aid is EBS P130, antioxidant 1010, and antioxidant 168 with a mass ratio of 2.5:1:1; the length-diameter ratio of the screw of the co-rotating twin-screw extruder is 48:1. Under the conveying, shearing, and mixing of the co-rotating twin-screw extruder, it is fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are as follows: the temperature of the feeding section is 130°C, 160°C, 170°C; the temperature of the plasticizing section is 180°C, 190°C, 190°C; the temperature of the homogenizing section is 190°C, 195°C, 195°C, 195°C, 200°C, 200°C; the temperature of the head is 205°C; the screw speed is 500 rmp, and the pressure is 6 MPa; then it is subjected to strand drawing, cooling, pelletizing, and drying to obtain an amino-POSS nano-modified polypropylene glass fiber composite material for 5G antenna radome with a glass fiber content of 40 wt.%.

[0055] Example 6

[0056] The preparation method of the amino-POSS nano-modified polypropylene glass fiber composite material for 5G antenna radome in this example includes the following steps:

[0057] S1 Preparation of amino-POSS grafted polyolefin masterbatch: The same as step S1 of Example 3;

[0058] S2 Preparation of Amino POSS Nanomodified Polypropylene Glass Fiber Composite for 5G Antenna Radome: Add 35.4 parts of polypropylene resin, 15 parts of amino POSS grafted polyolefin masterbatch, 8 parts of toughening agent POE8842, 0.8 part of light stabilizer UV-3808PP5, and 0.8 part of processing aid from the main feeding port of the co-rotating twin-screw extruder, and 40 parts of glass fiber from the side feeding port of the co-rotating twin-screw extruder into the co-rotating twin-screw extruder. The processing aid is composed of EBS P130, antioxidant 1010, and antioxidant 168 with a mass ratio of 2:1:1; the length-diameter ratio of the screws of the co-rotating twin-screw extruder is 48:1. Under the conveying, shearing, and mixing of the co-rotating twin-screw extruder, it is fully melted and mixed, and then extruded through the head of the co-rotating twin-screw extruder. The temperature settings of each temperature control zone of the co-rotating twin-screw extruder are as follows: the temperature of the feeding section is 130 °C, 160 °C, 170 °C; the temperature of the plasticizing section is 180 °C, 190 °C, 190 °C; the temperature of the homogenizing section is 190 °C, 195 °C, 195 °C, 195 °C, 200 °C, 200 °C; the temperature of the head is 205 °C; the screw speed is 400 rmp, and the pressure is 7 MPa; then it is subjected to strand drawing, cooling, pelletizing, and drying to obtain an amino POSS nanomodified polypropylene glass fiber composite for 5G antenna radome with a glass fiber content of 40 wt.%.

[0059] Comparative Example 1

[0060] The difference from Example 2 is that step S1 is not carried out; in step S2, the addition amount of polypropylene resin is 68.5 parts.

[0061] Comparative Example 2

[0062] The difference from Example 3 is that step S1 is not carried out; in step S2, the addition amount of polypropylene resin is 57.7 parts.

[0063] Comparative Example 3

[0064] The difference from Example 6 is that step S1 is not carried out; in step S2, the addition amount of polypropylene resin is 50.4 parts.

[0065] Comparative Example 4

[0066] The difference from Comparative Example 3 is that in step S2, the addition amount of polypropylene resin is 51 parts, and the addition amount of light stabilizer is 0.2 part.

[0067] Comparative Example 5

[0068] The difference from Example 1 is that step S1 is not carried out; in step S2, a 3-aminopropyl POSS and octa(3-aminopropyl) POSS-based amino POSS nanocomposite with a mass ratio of 3:1 is used to replace 10 parts of the amino POSS grafted polyolefin masterbatch; the addition amount of polypropylene resin is 72.9 parts.

[0069] Comparative Example 6

[0070] The difference from Example 1 is that in step S1, 3-aminopropyl POSS is used to equally replace octakis(3-aminopropyl) POSS.

[0071] Comparative Example 7

[0072] The difference from Example 1 is that in step S1, the maleic anhydride grafted polyolefin resin is PP-g-MAH.

[0073] Comparative Example 8

[0074] The difference from Example 1 is that in step S1, the maleic anhydride grafted polyolefin resin is POE-g-MAH.

[0075] Comparative Example 9

[0076] The difference from Example 1 is that in step S1, the nano-silica composition is nano-silica and titanium dioxide with a mass ratio of 1:2.

[0077] Comparative Example 10

[0078] The difference from Example 1 is that in step S1, the nano-silica composition is nano-silica and wollastonite with a mass ratio of 1:1.

[0079] In step S2 of Examples 1-6 and Comparative Examples 1-10, the addition amounts of each raw material are shown in Table 1:

[0080] Table 1 Addition amounts of each raw material in step S2 of Examples 1-6 and Comparative Examples 1-10 (parts by weight)

[0081]

[0082] Perform performance tests on the polypropylene glass fiber composites prepared in Examples 1-6 and Comparative Examples 1-10. The test results are shown in Table 2, and the test methods and standards are as follows:

[0083] The tensile strength was tested in accordance with "ASTM D638"; the flexural strength and flexural modulus were tested in accordance with "ASTM 790"; the notched Izod impact strength was tested in accordance with "ASTM 256"; the weather resistance was tested in accordance with "ISO 4892 Xenon Lamp Aging Test Method", and the test conditions were: 1500 h, the color difference (ΔE) of the material was evaluated, and the color difference (ΔE) of the material was used as an evaluation index for weather resistance performance; the impact resistance performance: measured by the falling weight impact test, and the test conditions were: at -40 °C, a 500 g steel ball, and the ball dropped from 1.3 m did not crack; the dielectric properties: tested in accordance with "GB / T 1409-2006", the test sample size was 60 mm × 40 mm × 1 mm, and the test resonance frequency was 16 GHz.

[0084] Table 2 Performance test results of polypropylene glass fiber composites in Examples 1-6 and Comparative Examples 1-10

[0085]

[0086] It can be seen from Comparative Examples 1-3 in Table 2 that if the amino POSS grafted polyolefin masterbatch is not added, the products with glass fiber contents of 20 wt.%, 30 wt.%, and 40 wt.% have large differences in both mechanical properties and dielectric properties compared with the products with the added amino POSS grafted polyolefin masterbatch. This is mainly because in the added grafted amino POSS masterbatch, due to chemical grafting, the nano POSS particles are highly dispersed in the polymer matrix, thereby improving the mechanical properties of the material and reducing the dielectric constant and dielectric loss of the material. The mechanical properties and dielectric properties of Comparative Example 4 are not much different from those of Comparative Example 3, but the weather resistance is significantly worse (the color difference ΔE has increased by more than one time), which is mainly caused by too little addition amount of the light stabilizer.

[0087] Compared with Example 1, in Comparative Example 5, the amino POSS nanocomposite was not chemically grafted. Due to the high surface energy of the amino POSS nanoparticles, they are extremely easy to self-polymerize and are very difficult to disperse in the composite material. Therefore, the reinforcing and toughening effects of the POSS nanoparticles are very limited, and the reduction effects on the dielectric constant and dielectric loss of the material are not obvious, resulting in worse mechanical properties and dielectric properties of Comparative Example 5 than those of Example 1.

[0088] In Comparative Example 6, when preparing the amino POSS grafted polyolefin masterbatch, only 3-aminopropyl POSS was added to the amino POSS nanocomposite, and octakis(3-aminopropyl) POSS was not added, resulting in a significant reduction in the mechanical properties and dielectric properties of the final prepared amino POSS nanomodified polypropylene glass fiber composite product for 5G radomes, indicating that octakis(3-aminopropyl) POSS has a significant effect on improving the mechanical properties and dielectric properties of the material due to micro-crosslinking.

[0089] In Comparative Examples 7-8, PP-g-MAH or POE-g-MAH was used alone, which ultimately led to a decrease in the mechanical and dielectric properties of the product. This is mainly because the binary maleic anhydride grafted polyolefin resin (i.e., PP-g-MAH and POE-g-MAH) has a synergistic effect on the grafting of amino POSS and the dispersion of nanoparticles in the composite matrix. In Comparative Examples 9-10, the components of the nano-silica composition were changed, indicating that wollastonite can improve the mechanical properties of the product, while titanium dioxide can improve the weather resistance of the product. Silicon dioxide, titanium dioxide and wollastonite in the nano-silica composition have a synergistic effect in enhancing the mechanical properties of the product and reducing the dielectric constant and dielectric loss of the material.

[0090] The present invention enhances polypropylene materials by grafting amino POSS onto polyolefin nanomodified glass fibers. By using the methods of chemical reaction grafting and melt blending extrusion, a high-performance polypropylene glass fiber composite with excellent comprehensive properties such as mechanical properties, thermal properties, and dielectric properties is obtained. Compared with conventional polypropylene glass fiber composites, the dielectric constant and dielectric loss of the amino POSS nanomodified polypropylene glass fiber composite of the present invention are significantly reduced, and the tensile strength, flexural strength, flexural modulus, impact resistance, etc. are greatly improved, meeting the stringent requirements of 5G communication for materials.

Claims

The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 1.5G antenna cover is characterized in that: The following steps are involved: S1: 70-90 parts of maleic anhydride grafted polyolefin resin, 10-20 parts of amino POSS nanocomposite, 3-5 parts of nano-silicon dioxide composition and 0.8-1.5 parts of processing aid are added into a twin-screw extruder through a measuring scale, and the twin-screw extruder is used for reaction extrusion, granulation and drying to obtain amino POSS grafted polyolefin masterbatch; S2: 30-70 parts of polypropylene resin, 10-20 parts of amino POSS grafted polyolefin masterbatch, 5-10 parts of toughening agent, 0.3-0.8 parts of light stabilizer, 0.8-1.5 parts of processing aid are added into the twin-screw extruder from the main feeding port of the twin-screw extruder, and 20-40 parts of glass fiber are added from the side feeding port of the twin-screw extruder, and the amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover is obtained through melt blending reaction, extrusion, drawing, cooling, pelletizing and drying in the twin-screw extruder; in steps S1 and S2, the addition amount of each raw material is measured in parts by weight.

2. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S1, the maleic anhydride grafted polyolefin resin is maleic anhydride grafted polypropylene and maleic anhydride grafted polyolefin elastomer POE in a mass ratio of (2-4):

1.

3. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 2, characterized in that, In step S1, the amino POSS nanocomposite is 3-aminopropyl POSS and octa(3-aminopropyl)POSS in a mass ratio of (3-4):

1.

4. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S1, the nano-silicon dioxide composition is nano-silicon dioxide, titanium dioxide and wollastonite in a mass ratio of (1-2):(2-3):

1.

5. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S1, the twin-screw extruder is a co-rotating twin-screw extruder, the screw aspect ratio is (48-52):1, the feeding section temperature is 120-160°C, the plasticizing section temperature is 150-180°C, the homogenizing section temperature is 160-190°C, the head temperature is 180-190°C, the screw speed is 100-300rmp, and the pressure is 3-6MPa.

6. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S2, the toughening agent is at least one of ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene propylene diene monomer rubber and ethylene-alpha olefin copolymer.

7. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S2, the light stabilizer is at least one of benzophenone weathering agent UV-531, benzotriazole weathering agent UV-326, hindered amine weathering agent UV-770 and UV-3808PP5.

8. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, In step S2, the twin-screw extruder is a co-rotating twin-screw extruder, the screw aspect ratio is (40-48):1, the feeding section temperature is 130-180°C, the plasticizing section temperature is 150-190°C, the homogenizing section temperature is 160-200°C, the die head temperature is 190-210°C, the screw speed is 200-600rmp, and the pressure is 6-10MPa.

9. The preparation method of amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as claimed in claim 1, characterized in that, The processing aids include lubricants and antioxidants, wherein the lubricants are one or more of silicone powder, white oil, polyethylene wax, ethylene bisstearamide and pentaerythritol stearate; and the antioxidants are at least two of antioxidant 1010, antioxidant 1076, antioxidant 168 and distearyl thiodipropionate. The amino POSS nano-modified polypropylene glass fiber composite material for 10.5G antenna cover is characterized by: The composite material is prepared by the method for preparing amino POSS nano-modified polypropylene glass fiber composite material for 5G antenna cover as described in any one of claims 1 to 9.

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