High-temperature-resistant glass fiber reinforced PP composite material and preparation process thereof

Abstract

The invention discloses a high-temperature-resistant glass fiber reinforced PP (polypropylene) composite material which is characterized by being prepared from the following components: 55-65 parts of PP resin, 30-45 parts of modified glass fiber, 8-12 parts of a compatibilizer, 0.3-1 part of an antioxidant, 1-5 parts of a flexibilizer and 1-5 parts of inorganic filler, the parts are all in parts by weight. The invention also discloses a preparation process of the high-temperature-resistant glass fiber reinforced PP composite material. Modified glass fibers are adopted, and the surfaces of the glass fibers are subjected to dipping pretreatment; in addition, the silane coupling agent is adopted to perform graft modification on the PP resin, and alkali liquor treatment is adopted, so that the compatibility of the PP and the glass fibers is further enhanced, and the interface bonding strength is improved. The glass fiber reinforced PP composite material provided by the invention has mechanical properties and high-temperature aging resistance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a high temperature resistant glass fiber reinforced PP composite material and a preparation process thereof. Background Art

[0002] Polypropylene (PP) is a general-purpose thermoplastic with excellent comprehensive properties. It has the advantages of light weight, high strength, chemical corrosion resistance, low cost, and recyclability. However, since PP material contains tertiary carbon atoms, it is very sensitive to heat and oxygen and is prone to oxidative degradation, resulting in reduced mechanical properties.

[0003] Since the glass fiber itself has excellent heat resistance, the heat resistance of the material can be improved after adding polypropylene. The general heat resistance temperature can reach 135℃~145℃. Since polypropylene is a kind of polymer with very weak polarity, and glass fiber is a borosilicate glass with strong polarity, the compatibility between the glass fiber and the matrix resin interface is very poor. In actual production, solving the compatibility plays a vital role in improving the bonding strength between PP and glass fiber interfaces.

[0004] At present, maleic anhydride grafting modification is widely used as a compatibilizer. Maleic anhydride can only improve the interfacial bonding between glass fiber and polypropylene, so that the tensile strength of the composite material is improved to a certain extent, but the enhancement of the toughness and impact strength of the composite material is not obvious; and the free maleic anhydride will cause the product to turn yellow, affecting the appearance of the product; under high temperature and high pressure, the composite material will become brittle and the mechanical properties will be greatly reduced. Summary of the invention

[0005] The main technical problem solved by the present invention is to overcome the above-mentioned problems existing in the existing glass fiber reinforced PP composite materials, and to provide a high-temperature resistant glass fiber reinforced PP composite material based on organic silane coupling agent grafting modification technology to improve interface compatibility; by improving the extruder screw configuration, the fiber dispersion is enhanced, and the preparation process is simple and the cost is low.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is: a high temperature resistant glass fiber reinforced PP composite material, made of the following components: 55-65 parts of PP resin, 30-45 parts of modified glass fiber, 8-12 parts of compatibilizer, 0.3-1 part of antioxidant, 1-5 parts of toughening agent and 1-5 parts of inorganic filler; the above parts are all calculated by weight.

[0007] The modified glass fiber is immersed in an organic silane coupling agent / ethanol solution with a volume concentration of 3% for 12 hours, and then placed in an oven at 80° C. for drying for 2 hours after drying;

[0008] The compatibilizer adopts PP resin: silane coupling agent: diisopropylbenzene peroxide in a component ratio of 100:10:1, and the mixed raw materials are injected into a twin-screw extruder, cooled after melting reaction, cut into granules by a granulator, and then soaked in a 1 mol / L NaOH aqueous solution for 2 hours and dried to obtain the compatibilizer.

[0009] Preferably, the PP resin is a homopolymer PP resin having a melt index of 3 to 30 g / 10 min.

[0010] Preferably, the modified glass fiber is short glass fiber with a diameter of 6 to 10 μm.

[0011] Preferably, the antioxidant is one or more of antioxidant 1010, antioxidant AO-20, and antioxidant AO-30.

[0012] Preferably, the toughening agent is methyl methacrylate-butadiene-styrene copolymer.

[0013] Preferably, the filler is one or more of calcium carbonate, talc and mica.

[0014] The present invention also provides a preparation process of a high temperature resistant glass fiber reinforced PP composite material, comprising the following steps:

[0015] (1) mixing PP resin, a compatibilizer, an antioxidant, a toughening agent and an inorganic filler uniformly according to the weight proportions, and feeding the mixture into a twin-screw extruder from a main feed port;

[0016] (2) feeding the modified glass fiber in the amount of the above-mentioned weight portion into a twin-screw extruder from a side feed port, and pelletizing the melt-extruded glass fiber to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0017] Preferably, the rotation speed of the twin-screw extruder is 450-500 rpm.

[0018] Preferably, the extrusion port temperature of the screw extruder is 210-230°C.

[0019] Preferably, after the modified glass fiber is added, the screw configuration of the twin-screw extruder adopts a toothed disk element.

[0020] The beneficial effects of the present invention are as follows: Different from the prior art, based on the organosilane coupling agent grafting modification technology, on the one hand, the glass fiber is pre-treated by impregnation with organosilane; on the other hand, the PP is grafted with organosilane by an initiator to modify the compatibilizer to compatibilize the glass fiber PP composite material, and the organosilane reacts with the glass fiber and PP at the interface to form a certain strength of -Si-O-Si- chemical bond, thereby enhancing the interfacial adhesion; in addition, through the alkali solution treatment, the silicon hydroxyl etherification reaction occurs, thereby enhancing the overall bonding strength between the two phases. In the preparation process of the fiber-reinforced PP composite material, it is proposed that the screw configuration of the twin-screw extruder after the addition of glass fiber adopts a toothed disc element, which significantly improves the dispersion performance of the glass fiber, further improves the regularity of the composite material, and significantly improves its high temperature resistance. The present invention has the characteristics of simple process and low cost. DETAILED DESCRIPTION

[0021] The present invention will be further understood by the following specific examples and comparative examples of the present invention, but they are not intended to limit the present invention.

[0022] In addition, in the examples and comparative examples of the present invention, the tensile strength is measured with reference to GB / T 1040; the flexural strength and flexural modulus are measured with reference to GB / T 9341; and the heat deformation temperature is measured with reference to GB / T1634.

[0023] The glass fiber was impregnated with an organic silane coupling agent / ethanol solution with a volume concentration of 3% for 12 hours, and then placed in an oven at 80° C. for 2 hours to obtain a modified glass fiber;

[0024] The component ratio of PP resin: silane coupling agent: diisopropylbenzene peroxide is 100:10:1, and the mixed raw materials are injected into a twin-screw extruder. After the melting reaction, the mixture is cooled, cut into granules by a granulator, and then immersed in a 1 mol / L NaOH aqueous solution for 2 hours and dried to obtain a compatibilizer.

[0025] Embodiment 1:

[0026] The high temperature resistant glass fiber reinforced PP composite material is weighed according to weight: 55 parts of homopolymer PP resin with a melt index of 15g / 10min, 10 parts of a compatibilizer, 0.5 parts of an antioxidant 1010, 3.5 parts of methyl methacrylate-butadiene-styrene copolymer and 4.5 parts of calcium carbonate;

[0027] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 450 rpm; 30 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 220°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0028] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0029] Embodiment 2:

[0030] The high temperature resistant glass fiber reinforced PP composite material is weighed according to weight: 65 parts of homopolymer PP resin with a melt index of 25g / 10min, 12 parts of a compatibilizer, 0.3 parts of an antioxidant AO-20, 4 parts of a methyl methacrylate-butadiene-styrene copolymer and 3 parts of calcium carbonate;

[0031] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 500 rpm; 38 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 230°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0032] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0033] Embodiment 3:

[0034] The high temperature resistant glass fiber reinforced PP composite material is weighed according to weight: 58 parts of homopolymer PP resin with a melt index of 15g / 10min, 8 parts of a compatibilizer, 0.6 parts of an antioxidant AO-30, 3.5 parts of a methyl methacrylate-butadiene-styrene copolymer, 2 parts of calcium carbonate and 2 parts of talc;

[0035] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 500 rpm; 38 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 230°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0036] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0037] Embodiment 4:

[0038] The high temperature resistant glass fiber reinforced PP composite material is weighed according to weight: 60 parts of homopolymer PP resin with a melt index of 15g / 10min, 10 parts of a compatibilizer, 0.8 parts of an antioxidant AO-20, 2 parts of a methyl methacrylate-butadiene-styrene copolymer and 5 parts of calcium carbonate;

[0039] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 500 rpm; 45 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 210°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0040] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0041] Embodiment 5:

[0042] The high temperature resistant glass fiber reinforced PP composite material is weighed in parts by weight: 60 parts of homopolymer PP resin with a melt index of 20g / 10min, 10.5 parts of a compatibilizer, 0.5 parts of an antioxidant AO-20, 5 parts of a methyl methacrylate-butadiene-styrene copolymer and 3.5 parts of calcium carbonate;

[0043] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 480 rpm; 40 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 210°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0044] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0045] Embodiment 6:

[0046] The high temperature resistant glass fiber reinforced PP composite material is weighed in parts by weight: 55 parts of homopolymer PP resin with a melt index of 20g / 10min, 10 parts of a compatibilizer, 0.5 parts of an antioxidant AO-20, 3 parts of a methyl methacrylate-butadiene-styrene copolymer and 1 part of calcium carbonate;

[0047] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 500 rpm; 40 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 230°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0048] The specific technical indicators of the obtained high temperature resistant glass fiber reinforced PP composite material are shown in Table 1.

[0049] Comparative Example 1:

[0050] A glass fiber reinforced PP composite material is weighed in parts by weight: 55 parts of homopolymer PP resin with a melt index of 15 g / 10 min, 0.5 parts of antioxidant 1010, 3.5 parts of methyl methacrylate-butadiene-styrene copolymer and 4.5 parts of calcium carbonate;

[0051] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 300 rpm; 30 parts of unmodified glass fibers were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 220°C to obtain a glass fiber reinforced PP composite material.

[0052] The specific technical indicators of the obtained glass fiber reinforced PP composite material are shown in Table 1.

[0053] Comparative Example 2:

[0054] A glass fiber reinforced PP composite material is weighed in parts by weight: 60 parts of a homopolymer PP resin with a melt index of 15 g / 10 min, 10.5 parts of a maleic anhydride grafted PP resin, 0.5 parts of an antioxidant AO-20, 5 parts of a methyl methacrylate-butadiene-styrene copolymer, and 3.5 parts of calcium carbonate;

[0055] The above raw materials were mixed evenly, and fed into a twin-screw extruder from the main feeding port, with the speed of the twin-screw extruder being 250 rpm; 40 parts of modified glass fiber were fed into the twin-screw extruder from the side feeding port, and pelletized after melt extrusion. The extrusion port temperature was 230°C to obtain a high-temperature resistant glass fiber reinforced PP composite material.

[0056] The specific technical indicators of the obtained glass fiber reinforced PP composite material are shown in Table 1.

[0057] Table 1 Technical indicators of glass fiber reinforced PP composite materials

[0058]

[0059] It can be seen from Table 1 that compared with Comparative Example 1, the tensile strength, flexural modulus and high temperature resistance of Examples 1-6 are greatly improved after the glass fiber is modified by silane impregnation and the use of a compatibilizer; in addition, compared with Comparative Example 2 using maleic anhydride grafted PP resin as a compatibilizer, the high temperature resistance and mechanical properties are also greatly improved. The glass fiber reinforced PP composite materials obtained in Examples 1-6 have high modulus and high flexural strength while maintaining high tensile strength and high temperature resistance.

[0060] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention is based on the silane coupling agent grafting modification technology. On the one hand, the glass fiber is pre-treated by impregnation with organic silane; on the other hand, the PP is grafted with organic silane by an initiator to modify the compatibilizer to compatibilize the glass fiber PP composite material, and the organic silane reacts with the glass fiber and PP to form a certain strength of -Si-O-Si- chemical bond, thereby enhancing the interfacial adhesion; in addition, through the alkali solution treatment, the silicon hydroxyl etherification reaction occurs, thereby enhancing the overall bonding strength between the two phases. In the preparation process of the fiber-reinforced PP composite material, it is proposed that the screw configuration of the twin-screw extruder after adding the glass fiber adopts a toothed disc element, which significantly improves the dispersion performance of the glass fiber, further improves the regularity of the composite material, and significantly improves its high temperature resistance.

[0061] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the specification of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high temperature resistant glass fiber reinforced PP composite material, characterized in that: The invention is made of the following components: 55-65 parts of PP resin, 30-45 parts of modified glass fiber, 8-12 parts of a compatibilizer, 0.3-1 parts of an antioxidant, 1-5 parts of a toughening agent and 1-5 parts of an inorganic filler; the above parts are all by weight. The modified glass fiber is immersed in an organic silane coupling agent / ethanol solution with a volume concentration of 3% for 12 hours, and then placed in an oven at 80° C. for drying for 2 hours after drying; The compatibilizer adopts PP resin: silane coupling agent: diisopropylbenzene peroxide in a component ratio of 100:10:1, and the mixed raw materials are injected into a twin-screw extruder, cooled after melting reaction, cut into granules by a granulator, and then soaked in a 1 mol / L NaOH aqueous solution for 2 hours and dried to obtain the compatibilizer.

2. The high temperature resistant glass fiber reinforced PP composite material according to claim 1, characterized in that: The PP resin is a homopolymer PP resin with a melt index of 3 to 30 g / 10 min.

3. The high temperature resistant glass fiber reinforced PP composite material according to claim 1, characterized in that: The modified glass fiber is short glass fiber with a diameter of 6 to 10 μm.

4. The high temperature resistant glass fiber reinforced PP composite material according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1010, antioxidant AO-20 and antioxidant AO-30.

5. The high temperature resistant glass fiber reinforced PP composite material according to claim 1, characterized in that: The toughening agent is methyl methacrylate-butadiene-styrene copolymer.

6. The high temperature resistant glass fiber reinforced PP composite material according to claim 1, characterized in that: The filler is one or more of calcium carbonate, talc and mica.

7. A process for preparing a high temperature resistant glass fiber reinforced PP composite material according to any one of claims 1 to 6, characterized in that: The steps include: (1) Mix PP resin, a compatibilizer, an antioxidant, a toughening agent and an inorganic filler uniformly according to the weight proportions as described in claim 1, and feed the mixture into a twin-screw extruder from a main feed port; (2) feeding the modified glass fiber in the amount of the above-mentioned weight portion into a twin-screw extruder from a side feed port, and pelletizing the melt-extruded glass fiber to obtain a high-temperature resistant glass fiber reinforced PP composite material.

8. The preparation process of the high temperature resistant glass fiber reinforced PP composite material according to claim 7, characterized in that: The speed of the twin-screw extruder is 450-500 rpm.

9. The preparation process of the high temperature resistant glass fiber reinforced PP composite material according to claim 7, characterized in that: The extrusion port temperature of the screw extruder is 210-230°C.

10. The preparation process of the high temperature resistant glass fiber reinforced PP composite material according to claim 7, characterized in that: After the modified glass fiber is added, the screw configuration of the twin-screw extruder adopts a toothed disc element.

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