Impact-resistant flame-retardant PET / PBT / TPEE composite material and preparation method thereof

Abstract

The application discloses an impact-resistant flame-retardant PET / PBT / TPEE composite material and a preparation method thereof. The composite material raw material comprises PET, PBT, TPEE, a flame retardant, a compatibilizer, a nano filler, dicumyl peroxide and an antioxidant. PET, PBT and TPEE are all polyester structures, and have good compatibility; PBT improves the crystallization speed, TPEE improves the impact resistance, elongation at break and lowers the embrittlement temperature; the flame retardant is used to improve the flame-retardant property of the material; the nano filler is used to enhance the mechanical property and wear resistance; the compatibilizer is used to promote the better fusion between the flame retardant and the PET / PBT / TPEE molecular chain, and improve the impact resistance and the mechanical property. Dicumyl peroxide is a crosslinking agent, which promotes the free radical crosslinking reaction of the PET, PBT and TPEE molecular chain, increases the compatibility, improves the impact resistance, wear resistance and lowers the embrittlement temperature.

Description

Technical Field

[0001] This invention relates to the field of polymer compound composition technology, and more specifically, to an impact-resistant and flame-retardant PET / PBT / TPEE composite material and its preparation method. Background Technology

[0002] Polyethylene terephthalate (PET) is a commonly used engineering plastic. It possesses excellent oil resistance, resistance to dilute acids / alkalis, resistance to most solvents, abrasion resistance, heat resistance, good electrical insulation, high tensile strength, and low material cost, making it widely used in textile fibers, consumer blow molding, power tools, extruded sheets, office supplies, travel bags, automobiles, electronics, fiber optic cables, and home furnishings. However, due to PET's relatively high glass transition temperature and melting point, its crystallization rate during processing is slow, resulting in low production efficiency. Furthermore, its poor impact toughness and low-temperature brittleness hinder its application in certain areas. Additionally, its lack of flame retardancy, causing it to continue burning when exposed to fire, also limits its applications in flame-retardant applications. Therefore, toughening and improving impact strength, accelerating PET's crystallization rate, lowering its embrittlement temperature, improving low-temperature brittleness, and increasing flame retardancy have become crucial for PET's use as an engineering plastic.

[0003] Currently, there are methods that use PET / PBT alloys with flame retardants, such as Chinese patent application document (publication number: CN121249107A), which discloses a high-performance flame-retardant PBT / PET material and its preparation method, using a system of PET + polybutylene terephthalate (PBT) + flame retardant + chopped glass fiber + chain extender + polytetrafluoroethylene micro powder. PBT is a crystalline thermoplastic polyester with excellent oil resistance, acid / alkali resistance, resistance to most solvents, fast crystallization speed, and high tensile strength. However, PBT still suffers from poor notched impact strength, a high embrittlement temperature leading to low-temperature brittleness, continuous combustion upon exposure to fire, and high molding shrinkage. Since PET and PBT have similar molecular chain structures, blending them can combine the advantages of both. Adding flame retardants, chopped glass fibers, chain extenders, and polytetrafluoroethylene (PTFE) powder can significantly improve the flame retardancy, wear resistance, and compatibility of the PET / PBT alloy, and increase the crystallization and demolding speed. However, this flame-retardant PET / PBT alloy still suffers from low notched impact strength, high shrinkage, a high embrittlement temperature, and low-temperature brittleness. Furthermore, the addition of chopped glass fibers can lead to a rough surface, increased wear on equipment, reduced flowability of the composite material, and molding difficulties, thus limiting its application in some fields.

[0004] Currently, some methods involve adding flame retardants and toughening agents to PET. For example, Chinese patent application (publication number: CN118126503A) discloses a method for preparing flame-retardant PET material, which improves the flame retardancy of PET. Although the addition of nucleating agents and nucleation promoters can slightly increase the crystallization rate of PET, it does not significantly improve the crystallization demolding time. The added toughening agents, such as glass fiber or carbon fiber, do not improve the low-temperature brittleness of the material. Summary of the Invention

[0005] The purpose of this invention is to provide an impact-resistant and flame-retardant PET / PBT / TPEE composite material. This composite material has high impact strength, high elongation at break, excellent mechanical properties, high crystallization speed and is easier to process and mold, reduces embrittlement temperature, improves low-temperature brittleness, has excellent wear resistance and excellent flame retardancy.

[0006] Another objective of this invention is to provide a method for preparing an impact-resistant and flame-retardant PET / PBT / TPEE composite material.

[0007] Another objective of this invention is to provide an impact-resistant and flame-retardant PET / PBT / TPEE composite material that can be used in textile fibers, power tools, extruded sheets, office supplies, travel bags, automobiles, electronic appliances, optical fibers and cables, and home decoration.

[0008] The above-mentioned objectives of this invention are achieved through the following technical solutions.

[0009] This invention protects an impact-resistant and flame-retardant PET / PBT / TPEE composite material, comprising the following components by weight: PET 30-50 parts, PBT 10-20 parts, TPEE 10-22 parts, flame retardant 15-35 parts, compatibilizer 3-6 parts, nanofiller 5-15 parts, dicumyl peroxide 0.5-0.7 parts, and antioxidant 0.3-0.6 parts.

[0010] This invention combines PET, PBT, TPEE, flame retardants, and dicumyl peroxide, along with flame retardants, compatibilizers, nanofillers, dicumyl peroxide, and antioxidants. Utilizing the fact that PET, PBT, and TPEE all share a polyester structure, they possess good compatibility. PBT, a crystalline thermoplastic polyester, exhibits excellent oil resistance, acid / alkali resistance, resistance to most solvents, rapid crystallization, and high tensile strength. The addition of PBT increases the crystallization rate and tensile strength of PET. TPEE, a polyester elastomer, possesses high impact resistance, good low-temperature resistance, rapid crystallization, easy demolding, and acid / alkali resistance. The addition of TPEE improves the impact resistance of the composite material, increases its crystallization rate, facilitates demolding, lowers the embrittlement temperature, and mitigates low-temperature brittleness.

[0011] Flame retardants can enhance the flame retardant properties of materials; nanofillers can improve the mechanical properties and abrasion resistance of materials, and due to the small size effect of nanoparticles, they do not significantly affect the processing flow properties of the materials. Compatibilizers can promote better integration between flame retardants and the molecular chains of PET / PBT / TPEE, improving the impact resistance and mechanical properties of the materials. Dicumyl peroxide, as a crosslinking agent, promotes free radical crosslinking reactions between the molecular chains of PET, PBT, and TPEE, further increasing the compatibility between materials, improving impact resistance and abrasion resistance, further reducing the embrittlement temperature, and improving low-temperature brittleness.

[0012] Specifically, the PET is polyethylene terephthalate with a viscosity of 0.7-1.3 dL / g, in parts by weight of 30-50.

[0013] Preferably, the PET is polyethylene terephthalate with a viscosity of 0.8-1.0 dL / g and a weight fraction of 35-45 parts.

[0014] Specifically, the PBT is polybutylene terephthalate with a viscosity of 0.7-1.3 dL / g and a weight fraction of 10-20 parts.

[0015] Preferably, the PBT is polyethylene terephthalate with a viscosity of 0.9-1.1 dL / g and a weight fraction of 10-16 parts.

[0016] Specifically, the TPEE is a block polymer with a hard segment of polyester and a soft segment of polyether polyol, with a Shore hardness of 25D to 72D and a weight fraction of 10-22 parts.

[0017] Optionally, the thermoplastic polyester elastomer TPEE has a hard segment composed of polyester hard segments formed by the reaction of aromatic dicarboxylic acid and 1,4-butanediol, and a soft segment composed of a block polymer of polytetramethylene ether glycol, with a Shore hardness of 55D to 63D and a weight of 10-18 parts.

[0018] Preferably, the thermoplastic polyester elastomer TPEE has a hard segment made of polyester hard segment formed by the reaction of terephthalic acid and 1,4-butanediol, and a soft segment made of polytetramethylene ether glycol block polymer. The hardness is preferably 58D and the weight percentage is 18 parts.

[0019] Specifically, the flame retardants are phosphorus-based and nitrogen-based. The phosphorus-based flame retardant is one of polyphosphonate, ammonium polyphosphate, or cyclic methylphosphorus oxide. The nitrogen-based flame retardant is one of melamine, dicyandiamide, guanidine, or polycyanuric acid, in amounts of 20-35 parts by weight.

[0020] Preferably, the flame retardant is a phosphorus-based flame retardant and a nitrogen-based flame retardant, wherein the phosphorus-based flame retardant is a polyphosphonate and the nitrogen-based flame retardant is melamine; the ratio of the phosphorus-based flame retardant to the nitrogen-based flame retardant is 2:1, and the weight is 20-30 parts.

[0021] Specifically, the compatibilizer is POE grafted with maleic anhydride, in parts by weight of 5-6.

[0022] Specifically, the nanofiller material is at least one of nano-calcium carbonate, nano-talc powder, and nano-clay, in parts by weight of 5-15.

[0023] Preferably, the nanofiller is nano-talc powder, with a weight ratio of 5-10 parts.

[0024] Specifically, the dicumyl peroxide is present in an amount of 0.5-0.7 parts by weight.

[0025] Specifically, the antioxidant is a phenolic antioxidant, with a weight ratio of 0.3-0.6 parts.

[0026] Optionally, the phenolic antioxidant may be one or more of antioxidant 1010, antioxidant 1330 and antioxidant 1098, in parts by weight of 0.3-0.5.

[0027] Preferably, the phenolic antioxidant is antioxidant 1330, with a weight ratio of 0.3-0.4 parts.

[0028] This invention also protects a method for preparing an impact-resistant and flame-retardant PET / PBT / TPEE composite material, characterized by comprising the following steps: S1. Mix PET, PBT, TPEE, flame retardant, compatibilizer, nanofiller, dicumyl peroxide and antioxidant to form a solid one-step material; S2. The solid material from S1 is melt-extruded at 260°C using a twin-screw extruder with a length-to-diameter ratio of 44:1 to obtain an impact-resistant and flame-retardant PET / PBT / TPEE composite material.

[0029] Compared with existing technologies, the advantages of this invention are as follows: This composite material combines PET, PBT, TPEE, flame retardants, and dicumyl peroxide, along with other components. PET, PBT, and TPEE all have polyester structures, exhibiting good compatibility. PBT can increase the crystallization rate of PET, while TPEE can improve the material's impact resistance and lower its embrittlement temperature, thus mitigating low-temperature brittleness. The flame retardant enhances the material's flame retardant properties. Nanofillers enhance the material's mechanical properties and abrasion resistance. A compatibilizer promotes better integration between the flame retardant and the molecular chains of PET / PBT / TPEE, improving the material's impact resistance and mechanical properties. Dicumyl peroxide acts as a crosslinking agent, promoting free radical crosslinking reactions between the molecular chains of PET, PBT, and TPEE, further increasing the compatibility between materials, improving impact resistance and abrasion resistance, further lowering the embrittlement temperature, and mitigating low-temperature brittleness.

[0030] Compared to PET and other modified PET composites on the market, this composite material has high impact strength, high crystallization speed and is easier to process and mold, improves low-temperature brittleness and has excellent flame retardancy. Detailed Implementation

[0031] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments. Unless otherwise specified, the raw materials used in the present invention are all commonly used in the art.

[0032] Raw materials and reagents

[0033] 1. Component A: PET (polyethylene terephthalate), grade: CR8828, manufacturer: China Resources Chemical Materials Technology Co., Ltd.

[0034] 2. Component B: PBT (polybutylene terephthalate), brand name HQHX7100, manufacturer: Fujian Haiquan Chemical Co., Ltd.

[0035] 3. Component C: Thermoplastic polyester elastomer: TPEE, Shore hardness: 55D, model: Z155, manufacturer: Keheng Polymer (Guangdong) Co., Ltd.

[0036] 4. Component D: Flame retardant: polyphosphonate, model: Nofia HM1100, manufacturer: FRX Polymers, USA.

[0037] 5. Component E: Flame retardant: melamine, manufacturer: Sichuan Jinxiang Sairui Chemical Co., Ltd.

[0038] 6. Component F: Compatibilizer: POE grafted maleic anhydride, model: AMPLIFY GR216, manufacturer: Dow Chemical.

[0039] 7. Component G: Nanofiller: Nano talc powder, Model: YLK-555A, Manufacturer: Quanzhou Yiluoke New Material Co., Ltd.

[0040] 8. Component H: Dicumyl peroxide, Grade: RH DCP, Manufacturer: Shandong Boyuan Chemical Co., Ltd.

[0041] 9. Component I: Antioxidant: Phenolic antioxidant Irganox 1330, manufacturer: BASF, Germany. Example

[0042] Example 1 discloses an impact-resistant and flame-retardant PET / PBT / TPEE composite material, which is prepared by the following steps: S1. Mix 4000g of PET, 1600g of PBT, 1800g of TPEE, 1800g of polyphosphonate, 900g of melamine, 500g of POE grafted with maleic anhydride, 400g of nano talc, 50g of dicumyl peroxide and 40g of Irganox 1330 antioxidant evenly to form a solid one-step material; S2. The solid material from S1 is melt-extruded in a twin-screw extruder with a length-to-diameter ratio of 44:1. The melt extrusion temperatures are as follows: Zone 1 feed temperature 225℃, Zone 2 temperature 240℃, Zone 3 temperature 250℃, Zone 4 temperature 255℃, Zone 5 temperature 260℃, Zone 6 temperature 260℃, Zone 7 temperature 260℃, Zone 8 temperature 255℃, and the die head temperature is 255℃. The twin-screw speed is adjusted to 25 rpm, followed by water cooling and pelletizing to obtain an impact-resistant and flame-retardant PET / PBT / TPEE composite material.

[0043] The difference between Examples 2-6 and Example 1 is that the raw materials are the same, but the amount of raw materials used is different, and the preparation conditions are the same.

[0044] Comparative Example

[0045] The difference between Comparative Examples 1-6 and Example 1 is that the types of raw materials are fewer, the amounts of raw materials used are different, but the preparation conditions are the same.

[0046] The specific parameters of raw material usage for the examples and comparative examples are shown in the table below.

[0047] Table 1. Raw material consumption data for the examples and comparative examples.

[0048]

[0049] The composite materials obtained in Examples 1-6 and Comparative Examples 1-6 were subjected to performance tests, including hardness, tensile strength, elongation at break, notched impact strength, embrittlement temperature, wear resistance, demolding time, and flame retardancy, by injection molding (molding temperature 270℃) according to the test standards. The specific test standards and test results are shown in the table below.

[0050] Table 2 Data Table for Examples and Comparative Examples

[0051]

[0052] Experimental data from Examples 1-6 and Comparative Examples 1-6 show that the composite material combines PET, PBT, TPEE, flame retardant, and dicumyl peroxide, along with other components. Experimental data from Examples 2, 3, 4, 6 and Comparative Examples 1, 3 show that the addition of PBT increases the crystallization rate of the composite material, significantly shortening the injection molding demolding time; the more PBT added, the more pronounced the effect. Experimental data from Examples 2, 3, 4, 6 and Comparative Examples 1, 2 show that increasing TPEE improves the elongation at break, enhances impact resistance, lowers the embrittlement temperature, and mitigates low-temperature brittleness. Experimental data from Example 6 and Comparative Example 1 show that using a flame retardant improves the flame retardant performance, achieving a UL-94 V-0 rating. Experimental data from Example 6 and Comparative Examples 1, 4 show that using a compatibilizer promotes better fusion between the flame retardant and the molecular chains of PET / PBT / TPEE, improving the material's impact resistance and mechanical properties. Experimental data from Examples 1 and 6 and Comparative Examples 1 and 5 show that nanofiller materials can enhance the mechanical properties and wear resistance of materials. Experimental data from Examples 5 and 6 and Comparative Examples 1 and 6 show that dicumyl peroxide is a crosslinking agent that promotes free radical crosslinking reactions between PET, PBT, and TPEE molecular chains, further increasing the compatibility between materials. This significantly improves the elongation at break, impact resistance, wear resistance, and reduces the embrittlement temperature, thus improving low-temperature brittleness.

[0053] Compared to PET and other modified PET composites on the market, this composite material has high impact strength, high elongation at break, excellent mechanical properties, high crystallization speed and is easier to process and mold, lower embrittlement temperature, improved low-temperature brittleness, excellent wear resistance and excellent flame retardancy.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An impact-resistant and flame-retardant PET / PBT / TPEE composite material, characterized in that, By weight, it includes the following components: 30-50 parts PET, 10-20 parts PBT, 10-22 parts TPEE, 15-35 parts flame retardant, 3-6 parts compatibilizer, 5-15 parts nanofiller, 0.5-0.7 parts dicumyl peroxide, and 0.3-0.6 parts antioxidant.

2. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The PET is polyethylene terephthalate with a viscosity of 0.7-1.3 dL / g, and the PBT is polybutylene terephthalate with a viscosity of 0.7-1.3 dL / g.

3. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The TPEE is a block polymer with a hard segment of polyester and a soft segment of polyether polyol, and has a Shore hardness of 25D to 72D.

4. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The flame retardant is at least one of phosphorus-based flame retardants and nitrogen-based flame retardants. The phosphorus-based flame retardant is at least one of polyphosphonate, ammonium polyphosphate, and cyclic methyl phosphorus oxide. The nitrogen-based flame retardant is at least one of melamine, dicyandiamide, and polycyanuric acid.

5. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The compatibilizer is POE grafted with maleic anhydride.

6. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The nanofiller material is at least one of nano-calcium carbonate, nano-talc powder, and nano-clay.

7. The impact-resistant and flame-retardant PET / PBT / TPEE composite material according to claim 1, characterized in that, The antioxidant mentioned is a phenolic antioxidant.

8. A method for preparing an impact-resistant and flame-retardant PET / PBT / TPEE composite material according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix PET, PBT, TPEE, flame retardant, compatibilizer, nanofiller, dicumyl peroxide and antioxidant to form a solid one-step material; S2. The solid material from S1 is melt-extruded at 260°C using a twin-screw extruder to obtain an impact-resistant and flame-retardant PET / PBT / TPEE composite material.

9. An impact-resistant and flame-retardant PET / PBT / TPEE composite material according to any one of claims 1-7, or an impact-resistant and flame-retardant PET / PBT / TPEE composite material prepared by the preparation method according to claim 8, can be used in textile fibers, power tools, extruded sheets, office supplies, travel bags, automobiles, electronic appliances, optical fibers and cables, and home decoration.

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