Bamboo / wood / PP fiber felt for automotive trim and preparation method of composite material of bamboo / wood / PP fiber felt

Abstract

The invention belongs to the technical field of fiber felts, and particularly relates to a preparation method of a bamboo / wood / PP fiber felt for automotive interiors and a composite material of the bamboo / wood / PP fiber felt.The bamboo / wood / PP fiber felt is formed by opening, scattering, fully mixing and carding mixed fibers composed of wood fibers and modified bamboo fibers and PP fibers to form a fiber net, and then the fiber net is needled to form a dense felt material; wherein the modified bamboo fiber is prepared by the following steps: mixing 3, 5-di-tert-butyl-4-hydroxybenzaldehyde, methyl undecyl ketone, a sodium hydroxide solution and ethanol for reaction to obtain a hindered phenol material; mixing and reacting the hindered phenol material, chloroplatinic acid and tetrahydrofuran to obtain a long-chain alkyl hindered phenol grafted material; bamboo fibers, an ethanol solution and the long-chain alkyl hindered phenol grafting material are mixed and react, and modified bamboo fibers are obtained; the ultraviolet light stability of the bamboo / wood / PP fiber felt for the automotive trim is improved, and the tensile property of the bamboo / wood / PP fiber felt for the automotive trim can be greatly enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of fiber felts, and specifically relates to a preparation method of bamboo / wood / PP fiber felts and their composites for automotive interiors. Background Art

[0002] Automotive interior materials are mainly flax fiber boards, glass fiber boards, and bamboo fiber boards. The flax fiber board is made by mixing flax fibers with polypropylene staple fibers, needling them into a flax fiber felt, and then pressing them into a board using a press.

[0003] In the prior art, the temperature inside the vehicle can reach 80 - 120 °C in summer, which will greatly affect the antioxidant property of the fiber felt material for automotive interiors, related to the aging problem of the fiber felt material for automotive interiors. For example, long-term exposure to sunlight and high temperatures will cause the fiber felt material for automotive interiors to discolor and become brittle, which will further affect its use performance, specifically including the tensile property, which also decreases accordingly. Summary of the Invention

[0004] The purpose of the present invention is to provide a fibrous biomass-reinforced thermosetting bulk molding compound and its preparation method to solve the problems mentioned in the above background art.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A preparation method of a bamboo / wood / PP fiber felt composite for automotive interiors. After the mixed fibers composed of wood fibers and modified bamboo fibers and PP fibers are opened, dispersed, and fully mixed and carded to form a fiber web, it is made into a dense felt material through needling.

[0007] Among them, the preparation steps of the modified bamboo fibers are as follows:

[0008] Mix 3,5 - di - tert - butyl - 4 - hydroxybenzaldehyde, methyl undecyl ketone, sodium hydroxide solution, and ethanol, and react at 50 - 60 °C for 3 h to obtain a hindered phenol material.

[0009] Mix the hindered phenol material, chloroplatinic acid, and tetrahydrofuran, heat up to 100 - 110 °C, add triethoxysilane, and react for 4 h to obtain a long - chain alkyl hindered phenol grafted material.

[0010] Mix bamboo fibers, ethanol solution, and long - chain alkyl hindered phenol grafted material, adjust the pH, and react at 50 - 60 °C for 2 h to obtain modified bamboo fibers.

[0011] Furthermore, the dosage ratio of 3,5 - di - tert - butyl - 4 - hydroxybenzaldehyde, methyl undecyl ketone, sodium hydroxide solution, and ethanol is 45 - 50 mmol : 50 mmol : 20 - 30 mL : 40 - 50 mL.

[0012] Further, the sodium hydroxide solution is an aqueous sodium hydroxide solution with a mass fraction of 20%.

[0013] Further, the dosage ratio of the hindered phenol material, chloroplatinic acid, tetrahydrofuran, and triethoxysilane is 30 mmol: 0.5 g: 50 - 60 mL: 30 - 34 mmol.

[0014] Further, the ethanol solution is an aqueous ethanol solution with a volume fraction of 60 - 80%.

[0015] Further, the dosage ratio of bamboo fiber, ethanol solution, and long-chain alkyl hindered phenol grafted material is 20 - 25 g: 60 - 80 mL: 1 g.

[0016] Further, wood fiber and modified bamboo fiber are mixed to obtain mixed fiber in a mass ratio of 1:1.

[0017] Further, the mass ratio of the mixed fiber to the PP fiber is 25 - 35: 65 - 75.

[0018] Further, the pH is adjusted to 4 - 5.

[0019] The bamboo / wood / PP fiber felt composite material for automobile interior decoration includes: mixed fiber obtained by mixing wood fiber and modified bamboo fiber in a mass ratio of 1:1; the mass ratio of the mixed fiber to the PP fiber is 25 - 35: 65 - 75.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1) Using 3,5 - di - tert - butyl - 4 - hydroxybenzaldehyde and methyl undecyl ketone as raw materials, the aldehyde group of 3,5 - di - tert - butyl - 4 - hydroxybenzaldehyde reacts with the α - hydrogen of methyl undecyl ketone under alkaline conditions to undergo Claisen - Schmidt condensation to obtain a hindered phenol material with a double bond. Then, using the hindered phenol material and triethoxysilane as raw materials, the double bond of the hindered phenol material reacts with triethoxysilane under the catalysis of chloroplatinic acid to undergo hydrosilylation reaction to obtain a long - chain alkyl hindered phenol grafted material. Finally, the siloxane bond of the long - chain alkyl hindered phenol grafted material undergoes alcoholysis reaction under acidic conditions to graft the long - chain alkyl hindered phenol grafted material onto bamboo fiber to obtain modified bamboo fiber. Bamboo fiber has hydrophilicity because its surface contains a large number of hydrophilic hydroxyl groups. By modifying bamboo fiber, a long - chain alkyl hindered phenol grafted material with long - chain alkyl groups is grafted onto the surface of bamboo fiber, thereby obtaining modified bamboo fiber with hydrophobic surface, greatly improving the compatibility of modified bamboo fiber with epoxy resin. In addition, the surface of the modified bamboo fiber also has a hindered phenol group structure, with good antioxidant properties and good thermal stability, and is not easily inactivated.

[0022] 2) Under the condition that the modified bamboo fiber has hydrophobicity, compatibility, antioxidant property and thermal stability, by making a composite material from wood fiber, modified bamboo fiber and PP fiber, not only the ultraviolet stability of the bamboo / wood / PP fiber felt for automotive interior decoration is improved, but also the tensile resistance of the bamboo / wood / PP fiber felt for automotive interior decoration can be greatly enhanced. Detailed implementation mode

[0023] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0024] Embodiment 1

[0025] A modified bamboo fiber is made by the following steps:

[0026] Step 1: Mix 45 mmol of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 50 mmol of methyl undecyl ketone, 20 mL of a 20% by mass sodium hydroxide aqueous solution, and 40 mL of ethanol in a three-necked flask, install a condenser and a thermometer, turn on magnetic stirring, and react at a temperature of 50 °C for 3 h. After the reaction is completed, adjust the pH of the system to 5 with a 10% by mass dilute hydrochloric acid, then extract with dichloromethane, and separate the organic layer. After rotary evaporation of the organic layer, wash with deionized water and dry to obtain a hindered phenol material;

[0027] Step 2: Mix 30 mmol of the hindered phenol material, 0.5 g of chloroplatinic acid, and 50 mL of tetrahydrofuran in a three-necked flask, install a condenser and a thermometer, turn on magnetic stirring, raise the temperature of the system to 100 °C, and then add 30 mmol of triethoxyhydroxysilane dropwise to the three-necked flask. After the addition is completed, continue to react at a temperature of 100 °C for 4 h. After the reaction is completed, rotary evaporate to remove the solvent, and the remaining solid is obtained by silica gel column chromatography to obtain a long-chain alkyl hindered phenol grafted material;

[0028] Step 3: Mix 20 g of bamboo fiber, 60 mL of an ethanol aqueous solution with a volume fraction of 60%, and 1 g of the long-chain alkyl hindered phenol grafted material in a three-necked flask, install a condenser and a thermometer, turn on magnetic stirring, adjust the pH of the system to 4 with glacial acetic acid, and then react at a temperature of 50 °C for 2 h. After the reaction is completed, filter out the bamboo fiber, wash with ethanol and dry to obtain the modified bamboo fiber.

[0029] Embodiment 2

[0030] A modified bamboo fiber is made by the following steps:

[0031] Step 1: Mix 47 mmol of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 50 mmol of methyl undecyl ketone, 25 mL of 20% sodium hydroxide aqueous solution, and 45 mL of ethanol in a three-necked flask. Install a condenser and a thermometer, start magnetic stirring, and react at 55 °C for 3 h. After the reaction is completed, adjust the pH of the system to 5.5 with 15% dilute hydrochloric acid. Then extract with dichloromethane and separate the organic layer. After rotary evaporation of the organic layer, wash with deionized water and dry to obtain the hindered phenol material;

[0032] Step 2: Mix 30 mmol of the hindered phenol material, 0.5 g of chloroplatinic acid, and 55 mL of tetrahydrofuran in a three-necked flask. Install a condenser and a thermometer, start magnetic stirring, raise the temperature of the system to 105 °C, and then add 32 mmol of triethoxysilane dropwise to the three-necked flask. After the addition is completed, continue to react at 105 °C for 4 h. After the reaction is completed, rotary evaporate to remove the solvent, and obtain the long-chain alkyl hindered phenol grafted material through silica gel column chromatography;

[0033] Step 3: Mix 22 g of bamboo fiber, 70 mL of 70% ethanol aqueous solution, and 1 g of the long-chain alkyl hindered phenol grafted material in a three-necked flask. Install a condenser and a thermometer, start magnetic stirring, adjust the pH of the system to 4.5 with glacial acetic acid, and then react at 55 °C for 2 h. After the reaction is completed, filter out the bamboo fiber, wash with ethanol and dry to obtain the modified bamboo fiber.

[0034] Example 3

[0035] A modified bamboo fiber is prepared by the following steps:

[0036] Step 1: Mix 50 mmol of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 50 mmol of methyl undecyl ketone, 30 mL of 20% sodium hydroxide aqueous solution, and 50 mL of ethanol in a three-necked flask. Install a condenser and a thermometer, start magnetic stirring, and react at 60 °C for 3 h. After the reaction is completed, adjust the pH of the system to 6 with 20% dilute hydrochloric acid. Then extract with dichloromethane and separate the organic layer. After rotary evaporation of the organic layer, wash with deionized water and dry to obtain the hindered phenol material;

[0037] Step 2: Mix 30 mmol of the hindered phenol material, 0.5 g of chloroplatinic acid, and 60 mL of tetrahydrofuran in a three-necked flask. Install a condenser and a thermometer, start magnetic stirring, raise the temperature of the system to 110 °C, and then add 34 mmol of triethoxysilane dropwise to the three-necked flask. After the addition is completed, continue to react at 110 °C for 4 h. After the reaction is completed, rotary evaporate to remove the solvent, and obtain the long-chain alkyl hindered phenol grafted material through silica gel column chromatography;

[0038] Step 3: Mix 25 g of bamboo fiber, 80 mL of an ethanol aqueous solution with a volume fraction of 80%, and 1 g of a long-chain alkyl hindered phenol grafting material in a three-necked flask. Install a condenser and a thermometer, turn on magnetic stirring, adjust the pH of the system to 5 with glacial acetic acid, and then react at 60 °C for 2 h. After the reaction is completed, filter out the bamboo fiber, wash it with ethanol, and dry it to obtain modified bamboo fiber.

[0039] Example 4

[0040] The bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following proportions:

[0041] The wood fiber and the modified bamboo fiber of Example 1 are used to obtain mixed fibers according to a mass ratio of 1:1; the mass ratio of the mixed fibers to the PP fiber is 25:65;

[0042] The preparation method of the bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following steps:

[0043] According to the above proportions, the mixed fibers composed of wood fiber and modified bamboo fiber and the PP fiber are opened, dispersed, and fully mixed and carded to form a fiber web, and then made into a dense felt by needling.

[0044] Example 5

[0045] The bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following proportions:

[0046] The wood fiber and the modified bamboo fiber of Example 2 are used to obtain mixed fibers according to a mass ratio of 1:1; the mass ratio of the mixed fibers to the PP fiber is 30:70;

[0047] The preparation method of the bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following steps:

[0048] According to the above proportions, the mixed fibers composed of wood fiber and modified bamboo fiber and the PP fiber are opened, dispersed, and fully mixed and carded to form a fiber web, and then made into a dense felt by needling.

[0049] Example 6

[0050] The bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following proportions:

[0051] The wood fiber and the modified bamboo fiber of Example 3 are used to obtain mixed fibers according to a mass ratio of 1:1; the mass ratio of the mixed fibers to the PP fiber is 35:75;

[0052] The preparation method of the bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following steps:

[0053] According to the above ratio, the mixed fiber composed of wood fiber and modified bamboo fiber and PP fiber are opened, dispersed, fully mixed and carded to form a fiber web, and then needled into a dense felt material.

[0054] Comparative Example 1

[0055] Replace the "modified bamboo fiber obtained in Example 3" used in Example 6 with unmodified bamboo fiber, and keep the other conditions and preparation steps unchanged to prepare a bamboo / wood / PP fiber felt composite material for automobile interior decoration. The specific steps are as follows:

[0056] The mixed fiber is obtained by mixing wood fiber and bamboo fiber according to a mass ratio of 1:1; the mass ratio of the mixed fiber to PP fiber is 35:75;

[0057] A preparation method of a bamboo / wood / PP fiber felt composite material for automobile interior decoration includes the following steps:

[0058] According to the above ratio, the mixed fiber composed of wood fiber and modified bamboo fiber and PP fiber are opened, dispersed, fully mixed and carded to form a fiber web, and then needled into a dense felt material.

[0059] Perform performance tests on the bamboo / wood / PP fiber felt composite materials for automobile interior decoration obtained in Examples 4-6 and Comparative Example 1. The test results are shown in Table 2:

[0060] Impact resistance performance test: Refer to the national standard GB / T 1843-2008 "Determination of Impact Strength of Plastics (Notched Izod Impact Test for Simply Supported Beams)" to test the impact strength.

[0061] Tensile property test: Refer to the national standard GB / T1040-2006 "Determination of Tensile Properties of Plastics" to test the tensile properties.

[0062] Antioxidant performance test: Cut each component plastic into plastic squares of 10 cm×10 cm×1 cm, and place the plastic squares in an oven at 120 °C for oxidation for 8 h, and record the yellowing value △E before and after oxidation.

[0063] Table 2

[0064]

[0065]

[0066] As can be seen from Table 2, the tensile strengths of the bamboo / wood / PP fiber felts of the present invention in Examples 4-6 are all higher than those of the bamboo / wood / PP fiber felts prepared from unmodified bamboo fiber, indicating that the bamboo / wood / PP fiber felts for automobile interior decoration of the present invention have excellent mechanical properties, and the oxidation yellowing quality at high temperature is lower than that of bulk molding compounds, having good antioxidant properties.

[0067] The above has introduced in detail a fibrous biomass-reinforced thermosetting bulk molding compound and its preparation method provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combination method. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and modifications can be made to the present invention without departing from the principle of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed by the present invention can be combined with each other in any way. The reason for not exhaustively describing the situations of these combinations in this specification is only to save space and resources. Therefore, the present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a bamboo / wood / PP fiber felt composite material for automobile interior, characterized in that: The mixed fiber composed of wood fiber and modified bamboo fiber and PP fiber are opened, scattered, fully mixed and combed to form a fiber web, and then needle-punched into a dense felt material; The steps of preparing the modified bamboo fiber are as follows: Mix 3,5-di-tert-butyl-4-hydroxybenzaldehyde, methyl undecyl ketone, sodium hydroxide solution and ethanol, and react at 50-60° C. for 3 hours to obtain a hindered phenol material; Mix the hindered phenol material, chloroplatinic acid and tetrahydrofuran, raise the temperature to 100-110° C., add triethoxysilane, and react for 4 hours to obtain a long-chain alkyl hindered phenol grafted material; The bamboo fiber, ethanol solution and long-chain alkyl hindered phenol grafting material are mixed, the pH is adjusted, and the mixture is reacted at 50-60° C. for 2 hours to obtain modified bamboo fiber.

2. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 1, characterized in that: The dosage ratio of 3,5-di-tert-butyl-4-hydroxybenzaldehyde, methyl undecyl ketone, sodium hydroxide solution and ethanol is 45-50 mmol: 50 mmol: 20-30 mL: 40-50 mL.

3. The method for preparing the bamboo / wood / PP fiber felt for automobile interior and the composite material thereof according to claim 1, characterized in that: The sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass fraction of 20%.

4. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 1, characterized in that: The usage ratio of hindered phenol material, chloroplatinic acid, tetrahydrofuran and triethoxysilane is 30mmol:0.5g:50-60mL:30-34mmol.

5. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 1, characterized in that: The ethanol solution is an ethanol aqueous solution with a volume fraction of 60-80%.

6. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 1, characterized in that: The usage ratio of bamboo fiber, ethanol solution and long-chain alkyl hindered phenol grafting material is 20-25g:60-80mL:1g.

7. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 1, characterized in that: The wood fiber and the modified bamboo fiber are mixed in a ratio of 1:1 by mass to obtain mixed fibers.

8. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 7, characterized in that: The mass ratio of the mixed fiber to the PP fiber is 25-35:65-75.

9. The method for preparing the bamboo / wood / PP fiber felt composite material for automobile interior decoration according to claim 7, characterized in that: The pH was adjusted to 4-5.

10. A bamboo / wood / PP fiber felt composite material for automobile interior, characterized in that: The composite material is prepared by the method described in any one of claims 1 to 9. The bamboo / wood / PP fiber felt composite material for automobile interior comprises: mixed fibers obtained by mixing wood fibers and modified bamboo fibers in a mass ratio of 1:1; and the mass ratio of the mixed fibers to the PP fibers is 25-35:65-75.

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