Method and application of melt catalytic modified bamboo powder / polypropylene composite material

Abstract

The invention discloses a method and application of melt catalytic modified bamboo powder / polypropylene composite material. The preparation method of the composite material has the following steps: uniformly spraying a water-alcohol solution of a composite silane coupling agent onto the surface of bamboo powder, drying, and obtaining modified bamboo powder; uniformly mixing polypropylene, silicone masterbatch (containing 50% polydimethylsiloxane), modified bamboo powder, and acetylacetonate cobalt / acetylacetonate manganese catalyst in different temperature zones, and melt extruding to obtain a modified bamboo powder / polydimethylsiloxane / polypropylene composite material. The invention utilizes the alkoxyl group of the composite silane coupling agent to hydrolyze to form silanol, which reacts with the hydroxyl group on the surface of bamboo powder to form hydrogen bonds and condense into covalent bonds. At the same time, the amine group and the imine group in the coupling agent can also form hydrogen bonds with the hydroxyl group to hydrophobically modify the bamboo powder. The polydimethylsiloxane in the silicone masterbatch and the silanol group on the surface of the modified bamboo powder undergo a dehydrogenation reaction through melt catalysis to generate a stable chemical bond and form an interface layer, so that the bamboo powder and the polypropylene achieve a compatibility enhancement effect.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene composite materials, in particular to a method for melt-catalyzed modification of bamboo powder / polypropylene composite materials and application thereof. Background Art

[0002] Polypropylene (PP) plastic is a non-toxic, odorless, tasteless, milky white, highly crystalline polymer with good thermal stability, rigidity and toughness. Therefore, it is widely used in the production of high-temperature resistant parts and structural parts. At the same time, PP has good mechanical properties, high tensile strength and impact strength, and is suitable for making high-strength products. In addition, the performance of PP can be changed by adding fillers. For example, the rigidity and strength of PP can be enhanced by adding glass fiber, wood powder and bamboo powder. As a kind of natural plant fiber, bamboo powder has many unique physical and chemical properties and excellent mechanical properties. Its strength and modulus are higher than many common synthetic materials, which can meet the requirements of automobiles, home appliances, etc. Bamboo powder also exhibits good thermal stability and chemical stability, and can maintain its performance stability under a wide range of temperature and chemical environments.

[0003] Bamboo powder contains a large number of strongly polar hydrophilic hydroxyl groups, which will lead to poor compatibility with the non-polar hydrophobic PP interface, affect the interface thickness, morphology, structure and dispersion uniformity of the material, and ultimately lead to poor material performance. For example, the modified bamboo wood powder is carried out in a water system, in which KH570 and KH550 or a mixture of two other coupling agents are added, and the temperature and time are controlled during the reaction process, which is not conducive to the industrial production of modified bamboo powder, and additional products need to be removed. For another example, by adding silane and titanate coupling agents and polydimethylsiloxane without a carrier, the compatibility of wood powder, bamboo powder and resin matrix is ​​improved, and the composite of wood powder, bamboo powder and resin matrix is ​​promoted. This coupling agent is a simple one-time physical addition method, which is not friendly to dispersibility and has a small modification effect; and polydimethylsiloxane without a carrier is not very compatible with the resin matrix, and no chemical bond is formed between the filler and the resin. In addition, high-strength plywood is prepared by adding methyltrimethoxysilane, polydimethylsiloxane and bamboo powder. The interaction between bamboo powder and resin matrix relies on intermolecular forces, and the process is complicated. It is suitable for small-scale preparation in the laboratory but not suitable for industrial production. Summary of the invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a method and application of melt catalytic modified bamboo powder / polypropylene composite materials, which can solve the problem of poor compatibility between PP and bamboo powder, effectively improve the crystallization of PP, and improve the mechanical properties and heat resistance of PP.

[0005] The method for melt catalytically modifying bamboo powder / polypropylene composite material proposed by the present invention comprises the following steps: uniformly mixing polypropylene, silicone masterbatch, modified bamboo powder and catalyst in different temperature zones, and melt extruding to obtain the modified bamboo powder / polypropylene composite material.

[0006] Preferably, the preparation method of the modified bamboo powder is: using γ-aminopropyltriethoxysilane and γ-aminoethylaminopropyltrimethoxysilane as a composite silane coupling agent to modify the bamboo powder.

[0007] Preferably, the mass ratio of the composite silane coupling agent to the bamboo powder is 0.004-0.02:1.

[0008] Preferably, the mass ratio of γ-aminopropyltriethoxysilane to γ-aminoethylaminopropyltrimethoxysilane is 1-2:1.

[0009] Preferably, the bamboo powder is dried at a temperature of 80-100° C. and for a period of 6-12 hours after modification.

[0010] Preferably, the mass ratio of polypropylene, silicone masterbatch, modified bamboo powder and catalyst is 1:0.02-0.08:0.2-0.5:0.0001-0.0005; the catalyst is compounded with cobalt acetylacetonate and manganese acetylacetonate in a mass ratio of 1-3:3-1.

[0011] Preferably, the temperature zone mixing process is as follows: the mixing temperature in the first stage is 30-45°C and the time is 0.5-1h; the mixing temperature in the second stage is 100-120°C and the time is 2-3h; the mixing temperature in the third stage is 25-35°C and the time is 1-2h.

[0012] Preferably, the melt extrusion conditions are: screw speed is 100-150 rpm, feeding rate is 5-7 Hz, and extrusion temperature zones are set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0013] The invention provides a modified bamboo powder / polypropylene composite material prepared by the method.

[0014] The modified bamboo powder / polypropylene composite material proposed by the present invention is applied in the fields of automobiles and household appliances.

[0015] Beneficial technical effects of the present invention:

[0016] (1) In the present invention, since bamboo powder has a large specific surface area and is easy to agglomerate, but has poor adhesion, a coupling agent can be used to modify bamboo powder, and the use of a composite silane coupling agent has a better effect. This paper uses KH550 and KH792 composite coupling agents to improve the hydrophobicity of the bamboo powder interface. Compared with KH550 (which has only one amine group), KH792 has both an amine group and an imine group, which can obtain higher binding energy and binding density, and induce a larger number of hydrogen bonds to form at the interface to improve and modify the interface. In addition, the molecular volume of KH550 is small, which is conducive to entering the internal porous system of bamboo powder, while KH792 with a large molecular volume is more inclined to produce a coupling effect on the surface of bamboo powder, so KH550 and KH792 can produce a synergistic coupling effect.

[0017] (2) In the present invention, in the first stage of mixing the raw materials in the temperature zone, the composite catalyst and each resin filler are relatively uniformly mixed, the temperature rises in the second stage, so that the catalyst can be coated with the softened resin, so that the catalyst is incorporated into the resin matrix, and the temperature begins to cool in the third stage, and the overall material tends to be uniform and stable, which is conducive to the next step of processing. Therefore, under the conditions of melt extrusion, the cobalt acetylacetonate and manganese acetylacetonate catalysts undergo high-temperature sintering to form a cobalt-manganese composite material. Before the incorporation of divalent cobalt ions, the main valence state of manganese ions is positive trivalent. After doping, the valence state of manganese ions tends to increase with the incorporation of cobalt ions. Such electronic rearrangement has a positive effect on the catalytic process. The synergistic effect of the two different elements greatly increases the number of active sites in the catalyst and reduces impedance, which is conducive to enhancing the catalytic activity of the material.

[0018] (3) In the present invention, the silicone masterbatch is prepared from polydimethylsiloxane and PP. During the melting process, polydimethylsiloxane can react with the above-mentioned coupling agent-modified bamboo powder under the catalysis of the composite catalyst, and the silanol group on the surface of the bamboo powder and the methyl groups on both sides of the polydimethylsiloxane undergo a dehydrogenation reaction, thereby promoting the formation of -Si-O-Si-bonds, generating stable chemical bonds, and realizing covalent bonds. And because the polydimethylsiloxane in the silicone masterbatch uses PP as a carrier, it can be compatible and entangled with the added PP material and has excellent compatibility. This improves the compatibility between the overall bamboo powder filler and the PP resin matrix, and is expected to simultaneously improve the strength and toughness of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The infrared spectra of KBF / PP of Comparative Example 1 and PDMS-KKBF / PP of Example 1 proposed by the present invention;

[0020] Figure 2 It is a comparison diagram of the crystallization / melting curves of KBF / PP of Comparative Example 1 and PDMS-KKBF / PP of Example 1 proposed by the present invention; wherein (a) is a crystallization process of decreasing temperature, and (b) is a melting process of increasing temperature;

[0021] Figure 3 Schematic diagram of the PDMS-KKBF / PP synthesis mechanism proposed in the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further explained below in conjunction with specific embodiments.

[0023] Example 1

[0024] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0025] S1: Weigh 10g KH550, 10g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg bamboo powder (BF) and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in a forced air drying oven at 80℃ for 12h to obtain silane coupling agent modified BF (KKBF).

[0026] S2: Weigh 1kg PP, 0.02kg silicone masterbatch (50% polydimethylsiloxane PDMS), 0.2kg of the above KKBF and 0.1g of cobalt acetylacetonate Co(acac) 2 / 0.3g acetylacetonate manganese Mn(acac) 3 The compound agent is mixed in different temperature zones. The mixing temperature of the first stage is 45°C and the time is 0.5h. The mixing temperature of the second stage is 100°C and the time is 2h. The mixing temperature of the third stage is 35°C and the time is 1h.

[0027] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0028] Example 2

[0029] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0030] S1: Weigh 10g KH550, 10g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in an 80℃ forced air drying oven for 12h to obtain KKBF.

[0031] S2: Weigh 1kg PP, 0.04kg silicone masterbatch, 0.2kg of the above KKBF, 0.1g Co(acac) 2 and 0.3 g Mn(acac) 3 The compound agent is mixed in different temperature zones. The mixing temperature of the first stage is 45°C and the time is 0.5h. The mixing temperature of the second stage is 100°C and the time is 2h. The mixing temperature of the third stage is 35°C and the time is 1h.

[0032] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0033] Example 3

[0034] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0035] S1: Weigh 10g KH550, 10g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in an 80℃ forced air drying oven for 12h to obtain KKBF.

[0036] S2: Weigh 1kg PP, 0.02kg silicone masterbatch, 0.2kg of the above KKBF, 0.3g Co(acac) 2 and 0.1 g Mn(acac) 3 The compound agent is mixed in different temperature zones. The mixing temperature of the first stage is 45°C and the time is 0.5h. The mixing temperature of the second stage is 100°C and the time is 2h. The mixing temperature of the third stage is 35°C and the time is 1h.

[0037] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0038] Comparative Example 1

[0039] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0040] S1: Weigh 20g KH550, 72g ethanol and 8g deionized water, prepare a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in a forced air drying oven at 80℃ for 12h to obtain silane coupling agent modified BF (KBF).

[0041] S2: Weigh 1kg PP, 0.02kg silicone masterbatch (50% polydimethylsiloxane PDMS), 0.2kg of the above KBF, 0.1g Co(acac) 2 and 0.3 g Mn(acac) 3 The compound agent is mixed in different temperature zones. The mixing temperature of the first stage is 45°C and the time is 0.5h. The mixing temperature of the second stage is 100°C and the time is 2h. The mixing temperature of the third stage is 35°C and the time is 1h.

[0042] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0043] Comparative Example 2

[0044] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0045] S1: Weigh 20g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in an 80℃ forced air drying oven for 12h to obtain KBF.

[0046] S2: Weigh 1kg PP, 0.02kg silicone masterbatch (50% polydimethylsiloxane PDMS), 0.2kg of the above KBF, 0.1g Co(acac) 2 and 0.3 g Mn(acac) 3 The compound agent is mixed in different temperature zones. The mixing temperature of the first stage is 45°C and the time is 0.5h. The mixing temperature of the second stage is 100°C and the time is 2h. The mixing temperature of the third stage is 35°C and the time is 1h.

[0047] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0048] Comparative Example 3

[0049] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0050] S1: Weigh 10g KH550, 10g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in an 80℃ forced air drying oven for 12h to obtain KKBF.

[0051] S2: Weigh 1kg PP, 0.02kg silicone masterbatch (50% polydimethylsiloxane PDMS), 0.2kg of the above KKBF and 0.4g Co(acac) 2 , mixing in different temperature zones, the first stage mixing temperature is 45℃, the time is 0.5h, the second stage mixing temperature is 100℃, the time is 2h, and the third stage mixing temperature is 35℃, the time is 1h.

[0052] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0053] Comparative Example 4

[0054] The preparation method of the melt catalytic modified bamboo powder / polypropylene composite material proposed in this scheme has the following steps:

[0055] S1: Weigh 10g KH550, 10g KH792, 72g ethanol and 8g deionized water, prepare them into a uniform solution by ultrasound, and adjust the pH value of the solution to 4 with dilute hydrochloric acid; then, weigh 1kg BF and put it into a high-speed mixer, spray the above solution evenly on the surface of BF, and mix it at high speed at room temperature for 40min; finally, dry the above mixed BF in an 80℃ forced air drying oven for 12h to obtain KKBF.

[0056] S2: Weigh 1kg PP, 0.02kg silicone masterbatch (50% polydimethylsiloxane PDMS), 0.2kg of the above KKBF and 0.4g Mn(acac) 3, mixing in different temperature zones, the first stage mixing temperature is 45℃, the time is 0.5h, the second stage mixing temperature is 100℃, the time is 2h, and the third stage mixing temperature is 35℃, the time is 1h.

[0057] S3: The mixed masterbatch described in S2 was melt-extruded, the screw speed was 150 rpm, the feeding rate was 5 Hz, and the extrusion temperature zones were set to 165, 170, 170, 175, 180, 180, 175, 170°C.

[0058] The present invention conducts mechanical property tests on the samples prepared in Examples 1-3 and Comparative Examples 1-4 and the pure PP samples, and the results are shown in Table 1. The standard for the flexural strength and flexural modulus tests is GB / T 9341-2008 "Plastics - Determination of Flexural Properties"; the standard for the tensile strength and elongation at break tests is GB / T1040.1-2018 "Plastics - Determination of Tensile Properties".

[0059] Table 1 Mechanical properties of samples

[0060]

[0061]

[0062] As shown in Table 1, the sample prepared in Example 1 has the best mechanical properties, with a tensile strength of 36.75Mpa, an elongation at break of 690%, a flexural strength of 28.46Mpa, and a flexural modulus of 2.06GPa. The performance of the KKBF composite material modified by the composite coupling agent is better than that of the KBF composite material modified by the single coupling agent. This is because there are more hydroxyls on the surface of BF, and different coupling agents have different modification capabilities. The composite use of KH550 and KH792 reduces the modification failure rate, increases the modification effect, improves the dispersion stability, greatly enhances the hydrophobicity of BF, and strengthens the interfacial compatibility between the reinforcing phase BF and the matrix resin PP, and the mechanical properties are expressed well. It can be obtained from Examples 1, 3 and Comparative Examples 3, 4 that the ability of the catalytic compound is higher than that of the single catalyst, and the effect is better when the ratio of cobalt acetylacetonate to manganese acetylacetonate is 1:3, and the synergistic effect of the two catalysts is conducive to improving the mechanical properties. At the same time, the appropriate addition of silicone masterbatch in the embodiment is conducive to the good compatibility of BF and PP and the enhancement of the mechanical properties of the overall material, and the silicone masterbatch has a good demoulding effect.

[0063] The water contact angle test was performed on the unmodified BF, KKBF in Example 1, and KBF samples in Comparative Examples 1 and 2, as shown in Table 2 below. As can be seen from the table, the water contact angle of the unmodified BF is 62.2°, and the water contact angle of KKBF after the composite coupling agent modification is 105.6°, while the water contact angle of KBF after the single coupling agent modification is about 94°. There are many hydrophilic hydroxyl groups in BF, resulting in poor interfacial compatibility between bamboo powder and hydrophobic polymers, and hydrophobic modification is required to increase the compatibility of BF with the PP non-polar resin matrix. The use of the composite coupling agent can effectively increase the hydrophobicity of BF, which is better than the single coupling agent and improves the compatibility with the PP resin.

[0064] Table 2 Water contact angle test of unmodified BF and KBF

[0065]

[0066] The present invention performs infrared detection analysis on the KBF / PP samples in Comparative Example 1 and the PDMS-KKBF / PP samples in Example 1. The results are as follows: Figure 1 As shown. 2916cm -1 The nearby band is the CH bending vibration of methyl / methylene at 1564 cm -1 Appears at—NH 2 The N—H bending vibration absorption peak is the characteristic peak of KH550 and KH792, and is 1627cm in PDMS-KKBF / PP. -1 The peaks at 1084 and 1019 cm-1 are typical characteristics of amino group deformation fluctuations, indicating that BF interacts with the amino groups of the composite silane coupling agent. -1 There is a strong absorption peak at 1261cm, which is attributed to the Si-O stretching vibration peak in the PDMS main chain and the condensed Si-O-Si vibration peak. -1 and 787cm -1 The peaks correspond to C—H bending and Si—C stretching (Si—CH 3 ), indicating that the silanol of the coupling agent reacts with the side methyl of PDMS, and the PDMS macromonomer successfully dehydrogenates and condenses, so that PDMS-KH550 / KH792 can be relatively coated on the surface of BF to form a PDMS-KKBF structure, changing the hydrophilic state of BF. In addition, since PP is used as a carrier of PDMS, the modified BF can be well compatible with the PP matrix.

[0067] The present invention performs differential scanning calorimetry test on the KBF / PP of comparative example 1 and the PDMS-KKBF / PP of example 1. The results are as follows: Figure 2As shown, (a) is the cooling crystallization process, and (b) is the heating melting process; the details of the thermodynamic parameters of the samples are shown in Table 3.

[0068] Table 3 Thermodynamic parameters of samples

[0069]

[0070] Depend on Figure 2 (a) and Table 3 show that the crystallization temperature of the PDMS-KKBF / PP sample prepared in Example 1 is slightly higher than that of the KBF / PP sample in Comparative Example 1, which is 122.40°C. The crystallization peak is closer to the high temperature zone, the crystallization temperature and crystallization enthalpy increase, and the crystallinity increases. This is because the addition of silicone masterbatch catalyzes the formation of bond bridges between PDMS and KKBF, and then crosslinks in the PP blend system to achieve a nucleation effect. Figure 2 (b) and Table 3 show that after adding silicone masterbatch into the system, the melting temperature decreases and the melting peak area increases. The addition of PDMS can effectively affect the interface effect of KKBF / PP, promote crystal growth, and improve crystallinity, showing that PDMS-KKBF / PP has improved thermal properties compared with KBF / PP.

[0071] Figure 3 Schematic diagram of the preparation mechanism of the PDMS-KKBF / PP composite material proposed in the present invention. Figure 3 As shown, first in step ①, KH550 and KH792 are hydrolyzed in an acidic aqueous alcohol solution to form silanols; then in step ②, BF reacts with silanolized KH550 / KH792, the hydroxyl groups on the surface of BF and the silanol groups produce hydrogen bonds, and dehydration condensation forms covalent bonds, while the amine and imine groups in the coupling agent can form hydrogen bonds with the hydroxyl groups of BF to obtain modified KKBF. In step ③, silicone masterbatch is added to make the PDMS in the silicone masterbatch in Co(acac) 2 and Mn(acac) 3 Under the action of the compounding agent, a melt catalytic reaction occurs with KKBF, and finally a PDMS-KKBF / PP composite material is formed with the addition of PP resin. BF is modified by a double coupling agent reaction to obtain hydrophobic KKBF, which enhances the compatibility of BF and PP. Further, in the melt catalysis, a stable chemical bond is formed between PDMS and KKBF, making the overall structure stable and complex, showing good performance, and can be used in the automotive and home appliance fields.

Claims

1. A method for melt catalytic modification of bamboo powder / polypropylene composite material, characterized in that: The method comprises the following steps: uniformly mixing polypropylene, silicone masterbatch, modified bamboo powder and catalyst in different temperature zones, and melt-extruding to prepare a modified bamboo powder / polypropylene composite material; The preparation method of modified bamboo powder is as follows: using γ-aminopropyl triethoxysilane and γ-aminoethylaminopropyl trimethoxysilane as composite silane coupling agents to modify bamboo powder; The mass ratio of the composite silane coupling agent to the bamboo powder is 0.004-0.02:1; The mass ratio of γ-aminopropyltriethoxysilane to γ-aminoethylaminopropyltrimethoxysilane is 1-2:1; The mass ratio of polypropylene, silicone masterbatch, modified bamboo powder and catalyst is 1:0.02-0.08:0.2-0.5:0.0001-0.0005; The catalyst is compounded with cobalt acetylacetonate and manganese acetylacetonate in a mass ratio of 1-3:3-1; The silicone masterbatch is prepared from polydimethylsiloxane and PP, with polydimethylsiloxane accounting for 50% of the total mass.

2. The method for melt catalytic modification of bamboo powder / polypropylene composite material according to claim 1, characterized in that: The drying temperature of modified bamboo powder is 80-100℃ and the drying time is 6-12h.

3. The method for melt catalytic modification of bamboo powder / polypropylene composite material according to claim 1, characterized in that: The mixing process in different temperature zones is as follows: the mixing temperature in the first stage is 30-45°C and the time is 0.5-1h; the mixing temperature in the second stage is 100-120°C and the time is 2-3h; the mixing temperature in the third stage is 25-35°C and the time is 1-2h.

4. The method for melt catalytic modification of bamboo powder / polypropylene composite material according to claim 1, characterized in that: The melt extrusion conditions were as follows: screw speed was 100-150 rpm, feed rate was 5-7 Hz, and extrusion temperature zones were set at 165, 170, 170, 175, 180, 180, 175, 170°C.

5. A modified bamboo powder / polypropylene composite material prepared by the method according to any one of claims 1 to 4.

6. Application of the modified bamboo powder / polypropylene composite material as claimed in claim 5 in the fields of automobiles and household appliances.

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