Environment-friendly flame-retardant long glass fiber reinforced polypropylene material as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly flame-retardant long glass fiber reinforced polypropylene material as well as a preparation method and application thereof, and belongs to the field of preparation of polypropylene materials.The material is prepared from the following components in parts by mass: 20-30 parts of copolymerized PP (polypropylene); 20 to 30 parts of homopolymerized PP (polypropylene); 40 to 60 parts of long glass fiber; 1 to 3 parts of pentaerythritol; 2 to 5 parts of melamine; 3 to 6 parts of silicate; 3 to 6 parts of graphene; 0.5 to 2 parts of phytic acid; 0.1 to 1 part of an antioxidant; 0.1 to 1 part of a light stabilizer; and 1-3 parts of a lubricant. Through combination of multiple components and process improvement, the long glass fiber reinforced polypropylene material which can maintain flame retardance and mechanical properties and is environment-friendly is prepared.

Description

Technical Field

[0001] The invention belongs to the field of preparation of environmentally friendly flame-retardant long glass fiber reinforced polypropylene materials, and in particular provides an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material and a preparation method and application thereof. Background Art

[0002] The limitations of traditional halogenated flame retardants primarily lie in environmental risks. Brominated flame retardants (such as decabromodiphenyl ether) release toxic fumes and dioxins when burned, making them non-compliant with environmental regulations such as RoHS and REACH. Furthermore, they suffer from poor compatibility. The polarity difference between halogenated flame retardants and the PP matrix requires a large addition (20% to 30%), which degrades the material's mechanical properties (e.g., impact strength can be reduced by more than 50%).

[0003] Subsequent improvements were made by those skilled in the art, but these improvements resulted in deteriorated mechanical properties: excessive filling weakened the glass fiber reinforcement effect, resulting in a 30% to 40% drop in tensile strength. Furthermore, with the increasing demand for flame retardancy, flame retardancy and mechanical properties became incompatible. Flame retardants (especially inorganic fillers) disrupted the interfacial bond between glass fiber and PP, resulting in a decrease in glass fiber pullout force.

[0004] Therefore, it has become a difficult problem for technicians in this field to overcome to develop long glass fiber reinforced polypropylene materials that can maintain flame retardant and mechanical properties while also being environmentally friendly. Summary of the Invention

[0005] The present invention addresses the problems existing in the prior art and discloses an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material, a preparation method and application thereof. The present invention prepares an environmentally friendly long glass fiber reinforced polypropylene material that can maintain flame retardant and mechanical properties while maintaining flame retardant and mechanical properties through the combination of multiple components and process improvements.

[0006] The present invention is achieved in that:

[0007] An environmentally friendly flame-retardant long glass fiber reinforced polypropylene material, characterized in that, in parts by mass, the material is prepared from the following components:

[0008] Copolymer PP: 20-30 parts;

[0009] Homopolymer PP: 20-30 parts;

[0010] Long glass fiber: 40-60 parts;

[0011] Pentaerythritol: 1-3 parts;

[0012] Melamine: 2-5 parts;

[0013] Silicate: 3-6 parts;

[0014] Graphene: 3-6 parts;

[0015] Phytic acid: 0.5-2 parts;

[0016] Antioxidant: 0.1-1 part;

[0017] Light stabilizer: 0.1-1 part;

[0018] Lubricant: 1 to 3 parts.

[0019] Furthermore, the length of the long glass fiber is 18 mm.

[0020] Furthermore, the antioxidant is hindered phenol 1010 or 1076.

[0021] Furthermore, the light stabilizer is a hindered amine HALS.

[0022] Furthermore, the silicate is montmorillonite.

[0023] A method for preparing an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material, characterized in that the method comprises:

[0024] 1. Raw material pretreatment:

[0025] Long glass fiber drying: Place the long glass fiber (40-60 parts) in a blast oven at 120°C and dry for 4 hours to remove moisture (moisture content ≤ 0.05%) to prevent bubbles from forming during processing;

[0026] Graphene dispersion treatment: Graphene (3-6 parts) and homopolymer PP (20-30 parts) were premixed and dispersed in a high-speed mixer (2000 rpm) for 10 minutes to form a graphene masterbatch to improve its dispersibility in the matrix;

[0027] Microencapsulation of flame retardant: Pentaerythritol (1-3 parts), melamine (2-5 parts) and phytic acid (0.5-2 parts) were mixed, 10% silane coupling agent (KH-560) was added, and microencapsulated intumescent flame retardant (IFR) was prepared by spray drying, with the particle size controlled at 5-10 μm;

[0028] 2. Blending and granulation (twin-screw extruder):

[0029] The long glass fiber treated in step 1 (40-60 parts), graphene masterbatch, flame retardant from step 2, homopolymer PP (20-30 parts), antioxidant (0.1-1 part), light stabilizer (0.1-1 part), and lubricant (1-3 parts) are mixed and pelletized. Conventional screw elements are used in the conveying section, kneading blocks (45° / 90° alternating) are used in the melting section, and reverse screw elements are used in the dispersion section to ensure that the glass fiber length retention rate is ≥50%. This environmentally friendly flame-retardant long glass fiber reinforced polypropylene material has a wide range of applications.

[0030] The beneficial effects of the present invention compared with the prior art are:

[0031] The present invention uses silicate (montmorillonite) and graphene to synergistically use flame retardants to reduce the amount of flame retardants used. After testing, the amount of flame retardants used was reduced by 10% to 15%. Phytic acid is a new environmentally friendly flame retardant used in the present invention and is environmentally friendly. The present invention also uses the main antioxidant for the first time: hindered phenols 1010 or 1076 to capture free radicals, and hindered amines (HALS) are used as light stabilizers to improve weather resistance. Copolymer PP and homopolymer PP can provide matrix toughness to ensure that long glass fibers are evenly dispersed during processing. The preparation method of the present invention adopts a screw combination design: a "strong shear + weak shear" combination is adopted: the conveying section uses ordinary threaded elements, the melting section uses kneading blocks (45° / 90° alternating), and the dispersion section uses reverse threaded elements to ensure that the glass fiber length retention rate is ≥50%. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the following examples are given to further illustrate the present invention in detail. It should be noted that the specific implementation described here is only used to explain the present invention and is not intended to limit the present invention.

[0033] Example 1

[0034] A method for preparing an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material in this embodiment is as follows:

[0035] 1. Raw material pretreatment:

[0036] Long glass fiber drying: long glass fiber (60 parts) was placed in a blast oven at 120°C and dried for 4 hours to remove moisture (moisture content ≤ 0.05%);

[0037] Graphene dispersion treatment: Graphene (6 parts) and homopolymer PP (30 parts) were premixed and dispersed in a high-speed mixer (2000 rpm) for 10 minutes to form graphene masterbatch;

[0038] Microencapsulation of flame retardant: Pentaerythritol (3 parts), melamine (5 parts) and phytic acid (2 parts) were mixed, 10% silane coupling agent (KH-560) was added, and microencapsulated intumescent flame retardant (IFR) was prepared by spray drying. The particle size was controlled at 5-10 μm.

[0039] 2. Blending and granulation:

[0040] The long glass fiber (60 parts) treated in step 1, graphene masterbatch, flame retardant in step 2, homopolymer PP (30 parts), antioxidant (1 part), light stabilizer (1 part), and lubricant (3 parts) are mixed and granulated. Ordinary threaded elements are used in the conveying section, kneading blocks (45° / 90° alternating) are used in the melting section, and reverse threaded elements are used in the dispersion section to ensure that the glass fiber length retention rate is ≥50%.

[0041] Example 2

[0042] A method for preparing an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material in this embodiment is as follows:

[0043] 1. Raw material pretreatment:

[0044] Long glass fiber drying: Place the long glass fiber (40 parts) in a blast oven at 120°C and dry for 4 hours to remove moisture (moisture content ≤ 0.05%);

[0045] Graphene dispersion treatment: Graphene (3 parts) and homopolymer PP (20 parts) were premixed and dispersed in a high-speed mixer (2000 rpm) for 10 minutes to form graphene masterbatch;

[0046] Microencapsulation of flame retardant: Pentaerythritol (1 part), melamine (2 parts) and phytic acid (0.5 parts) were mixed, 10% silane coupling agent (KH-560) was added, and microencapsulated intumescent flame retardant (IFR) was prepared by spray drying. The particle size was controlled at 5-10 μm.

[0047] 2. Blending and granulation:

[0048] The long glass fiber (40 parts) treated in step 1, graphene masterbatch, flame retardant in step 2, homopolymer PP (20 parts), antioxidant (0.1 parts), light stabilizer (0.1 parts), and lubricant (1 part) are mixed and granulated. Ordinary threaded elements are used in the conveying section, kneading blocks (45° / 90° alternating) are used in the melting section, and reverse threaded elements are used in the dispersion section to ensure that the glass fiber length retention rate is ≥50%.

[0049] Example 3

[0050] A method for preparing an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material in this embodiment is as follows:

[0051] 1. Raw material pretreatment:

[0052] Long glass fiber drying: Place the long glass fiber (50 parts) in a blast oven at 120°C and dry for 4 hours to remove moisture (moisture content ≤ 0.05%);

[0053] Graphene dispersion treatment: Graphene (4 parts) and homopolymer PP (25 parts) were premixed and dispersed in a high-speed mixer (2000 rpm) for 10 minutes to form graphene masterbatch;

[0054] Microencapsulation of flame retardant: Pentaerythritol (2 parts), melamine (4 parts) and phytic acid (1 part) were mixed, 10% silane coupling agent (KH-560) was added, and microencapsulated intumescent flame retardant (IFR) was prepared by spray drying. The particle size was controlled at 5-10 μm.

[0055] 2. Blending and granulation:

[0056] The long glass fiber (50 parts) treated in step 1, graphene masterbatch, flame retardant in step 2, homopolymer PP (25 parts), antioxidant (0.1-1 parts), light stabilizer (0.6 parts), and lubricant (2 parts) are mixed and granulated. Ordinary threaded elements are used in the conveying section, kneading blocks (45° / 90° alternating) are used in the melting section, and reverse threaded elements are used in the dispersion section to ensure that the glass fiber length retention rate is ≥50%.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. An environmentally friendly flame retardant long glass fiber reinforced polypropylene material, characterized in that: The material is prepared from the following components in parts by mass: Copolymer PP: 20-30 parts; Homopolymer PP: 20-30 parts; Long glass fiber: 40-60 parts; Pentaerythritol: 1-3 parts; Melamine: 2-5 parts; Silicate: 3-6 parts; Graphene: 3-6 parts; Phytic acid: 0.5-2 parts; Antioxidant: 0.1-1 part; Light stabilizer: 0.1-1 part; Lubricant: 1 to 3 parts.

2. The environmentally friendly flame-retardant long glass fiber reinforced polypropylene material according to claim 1, characterized in that: The length of the long glass fiber is 18 mm.

3. The environmentally friendly flame-retardant long glass fiber reinforced polypropylene material according to claim 1, characterized in that: The antioxidant is hindered phenol 1010 or 1076.

4. The environmentally friendly flame-retardant long glass fiber reinforced polypropylene material according to claim 1, characterized in that: The light stabilizer is a hindered amine HALS.

5. The environmentally friendly flame-retardant long glass fiber reinforced polypropylene material according to claim 1, characterized in that: The silicate is montmorillonite.

6. A method for preparing an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material according to any one of claims 1 to 7, characterized in that: The method described is:

1. Raw material pretreatment: Long glass fiber drying: Place the long glass fiber (40-60 parts) in a blast oven at 120°C and dry for 4 hours to remove moisture (moisture content ≤ 0.05%); Graphene dispersion treatment: Graphene (3-6 parts) and homopolymer PP (20-30 parts) were premixed and dispersed in a high-speed mixer (2000 rpm) for 10 minutes to form graphene masterbatch; Microencapsulation of flame retardant: Pentaerythritol (1-3 parts), melamine (2-5 parts) and phytic acid (0.5-2 parts) were mixed, 10% silane coupling agent (KH-560) was added, and microencapsulated intumescent flame retardant (IFR) was prepared by spray drying, with the particle size controlled at 5-10 μm; 2. Blending and granulation: The long glass fiber (40-60 parts) treated in step 1, graphene masterbatch, flame retardant in step 2, homopolymer PP (20-30 parts), antioxidant (0.1-1 part), light stabilizer (0.1-1 part), and lubricant (1-3 parts) are mixed and granulated. Ordinary threaded elements are used in the conveying section, kneading blocks (45° / 90° alternating) are used in the melting section, and reverse threaded elements are used in the dispersion section to ensure that the glass fiber length retention rate is ≥50%.

7. Application of an environmentally friendly flame-retardant long glass fiber reinforced polypropylene material prepared by the preparation method according to claim 6.