Chain extender and preparation method thereof, and flame-retardant PC / PET alloy material and preparation method thereof

Abstract

The invention discloses a chain extender and a preparation method thereof, and a flame-retardant PC / PET alloy material and a preparation method thereof. The structural formula of the chain extender is shown in the specification. The flame-retardant PC / PET alloy material comprises the following raw materials in parts by weight: 30-80 parts of PC; 10 to 60 parts by weight of PET; 0-15 parts by weight of a chain extender; optionally, 0-5 parts by weight of a processing aid. The alloy material disclosed by the invention is excellent in flame retardant property, and good in mechanical property and stability.

Description

Technical Field

[0001] This invention relates to the field of modified plastics, specifically to a chain extender and a flame-retardant PC / PET alloy material. Background Technology

[0002] PC / PET alloys, prepared by blending polycarbonate (PC) and polyethylene terephthalate (PET), offer a complementary advantage by leveraging the strengths of both materials. On one hand, they improve the mechanical properties and aging resistance of polyester materials; on the other hand, they enhance the flowability and chemical resistance of polycarbonate. Therefore, PC / PET alloys are widely used in numerous fields, including automobiles, machinery, and home appliances.

[0003] During the preparation of PC / PET alloys, PET typically exhibits low melt strength and melt viscoelasticity due to its material properties. This makes PC / PET difficult to process and mold, and significantly reduces the material's impact resistance. Furthermore, the introduction of PET further reduces the material's flame retardancy, necessitating modification to improve the alloy's flame retardancy and meet relevant application requirements. These performance defects introduced during processing severely limit the material's application in various fields.

[0004] To improve the melt strength and viscoelasticity of PET through simple means, it is necessary to increase its molecular weight, and modification with reactive extrusion chain extenders is a common method. While commonly used chain extenders can improve this, they cannot simultaneously guarantee the flame retardant properties of the material.

[0005] The methods for preparing flame-retardant PC / PET materials in CN104710750A, CN104693762A and CN101570629A, which only involve adding additional flame retardants and chain extenders, pose a risk of flame retardant failure due to precipitation.

[0006] Developing a chain extender for flame-retardant PC / PET alloy materials is of great significance. Summary of the Invention

[0007] To address the above problems, this invention provides a chain extender and its preparation method, and a flame-retardant PC / PET alloy material and its preparation method. The alloy material of this invention has excellent flame-retardant properties and good mechanical properties.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] This invention provides a chain extender with the following structural formula:

[0010]

[0011] Preferably, the method for preparing the chain extender includes the following steps:

[0012] (1) Eugenol was reacted with epichlorohydrin to obtain eugenol glycidyl ether;

[0013] (2) The eugenol glycidyl ether obtained in step (1) is reacted with tetramethylcyclotetrasiloxane (D4H) to prepare organosilicon modified eugenol glycidyl ether (SiEEP).

[0014] Preferably, step (1) is carried out at 65-100°C for 4-6 hours.

[0015] Preferably, step (1) involves adding a phase transfer catalyst.

[0016] Preferably, step (1) involves adding a 30wt% to 60wt% aqueous solution of sodium hydroxide.

[0017] Preferably, the phase transfer catalyst is a quaternary ammonium salt, preferably one or more of benzyltriethylammonium chloride (TEBA), tetrabutylammonium bromide (TBAB), tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, and trioctylmethylammonium chloride.

[0018] Preferably, the amount of phase transfer catalyst added in step (1) is 3‰-8‰ of the mass of epichlorohydrin.

[0019] Preferably, step (2) is carried out at 50℃-80℃ for 18-24 hours.

[0020] Preferably, step (2) involves adding a catalyst.

[0021] Preferably, the catalyst in step (2) is a platinum metal, preferably one or more of chloroplatinic acid, platinum-carbon, and platinum.

[0022] Preferably, the amount of catalyst added in step (2) is 0.1‰-0.6‰ of the mass of tetramethylcyclotetrasiloxane.

[0023] This invention also provides a flame-retardant PC / PET alloy material, comprising the following raw materials in parts by weight:

[0024] 30-80 parts by weight of PC;

[0025] 10-60 parts by weight of PET;

[0026] 0-15 parts by weight of the chain extender described in this invention;

[0027] Optionally, 0-5 parts by weight of processing aid.

[0028] Preferably, the flame-retardant PC / PET alloy material comprises the following raw materials in parts by weight:

[0029] 50-80 parts by weight of PC;

[0030] 10-40 parts by weight of PET;

[0031] 0-10 parts by weight of the chain extender described in this invention;

[0032] Optionally, 0-5 parts by weight of processing aid.

[0033] The PC described in this invention, under test conditions of 300°C and 1.2 kg, has a melt flow index of 3-65 g / 10 min, preferably 5-50 g / 10 min, and more preferably 7-35 g / 10 min, such as Wanhua Chemical's 2150.

[0034] The PET described in this invention is polyethylene terephthalate with an intrinsic viscosity of 0.58 dl / g-0.87 dl / g, such as CZ328A from Sanfangxiang.

[0035] The flame-retardant PC / PET alloy material of the present invention comprises processing aids selected from one or more of the following: antioxidants, lubricants, ultraviolet absorbers, flame retardants, toughening agents, compatibilizers, light stabilizers, heat stabilizers, metal passivators, plasticizers, anti-sticking agents, colorants, coupling agents, nucleating agents, foaming agents, antibacterial agents, mildew inhibitors, acid removers, hydrolysis resistant agents, chain extenders, flow modifiers, transesterification inhibitors, matting agents, antistatic agents, reinforcing agents, fillers, antifogging agents, light diffusing agents, infrared absorbers, fluorescent whitening agents, and laser marking agents.

[0036] The antioxidants described in this invention are one or more of hindered phenols, phosphites, thioesters, benzofurans, acryloyl-modified phenols, and hydroxylamine antioxidants. Preferably, one or more of BASF's antioxidants Irganox 1076, Irganox 1010, Irganox 168, Irgafos 126, Irgafos P-EPQ, and Irganox B900 are used.

[0037] The lubricant described in this invention is one or more of the following: fatty alcohols, metallic soaps, fatty acids, fatty acid esters, lignite acid and its derivatives, amide waxes, saturated hydrocarbons, polyolefin waxes and their derivatives, organosilicon and silicone powders, and organofluorine compounds. Ester-based lubricants, such as PETS from Lonza, are preferred.

[0038] The ultraviolet absorber described in this invention is one or more of the following: benzophenones, benzotriazoles, triazines, benzoic acid esters, cyanoacrylates, and phenylimidazoliums. Preferably, one or more of benzotriazoles and triazines are used, such as Tinuvin 234, Tinuvin 360, and Tinuvin 1577 from BASF.

[0039] The transesterification inhibitors described in this invention are one or more of acetals, stearic acid, and metal salts, such as PGP from Quansheng Company.

[0040] This invention also provides a method for preparing the flame-retardant PC / PET alloy material, comprising the following steps:

[0041] (a) Premixing: PC, PET, chain extender and optional processing aids are added to a mixer in proportion and stirred to obtain a premix;

[0042] (b) Extrusion: The premixed material is extruded and granulated through a twin-screw extruder to obtain flame-retardant PC / PET alloy material.

[0043] Preferably, the conditions for step (b) include: a conveying section temperature of 210–240°C, a plasticizing section temperature of 230–270°C, a metering section temperature of 240–270°C, and a screw speed of 200–800 rpm.

[0044] The positive effects of this invention are as follows:

[0045] This invention uses organosilicon-modified eugenol glycidyl ether as a chain extender mixed with PC / PET materials. The modified chain extender achieves multi-site chain extension, and the formation of a branched structure further enhances the melt strength and viscoelasticity of the PET material, facilitating processing. The branched structure also improves the system's impact resistance. Furthermore, the introduction of organosilicon simultaneously improves the material's flame retardant properties, achieving a high-efficiency flame retardant effect without the need for additional flame retardants. The PC / PET material of this invention possesses both excellent flame retardant properties and superior impact resistance. Attached Figure Description

[0046] Figure 1 This is an infrared schematic diagram of the corresponding substance. Detailed Implementation

[0047] To better explain the present invention, the present invention will be further described in detail below with reference to the embodiments. However, the embodiments described in the present invention are only for illustration and do not limit the scope of the present invention.

[0048] The components of the comparative examples and embodiments are as follows:

[0049] Polycarbonate resin: 2150, melt flow index of 15g / 10min (300℃, 1.2kg), Wanhua Chemical Group Co., Ltd.

[0050] Polyethylene terephthalate resin: CZ-328A, Sanfangxiang Company, with an intrinsic viscosity of 0.87 dl / g;

[0051] Eugenol: Adamas Reagents Ltd.

[0052] Epichlorohydrin: Sinopharm Chemical Reagent Co., Ltd.

[0053] Sodium hydroxide: Sinopharm Chemical Reagent Co., Ltd.

[0054] Anhydrous magnesium sulfate: Adamas Reagents Ltd.

[0055] Tetrabutylammonium bromide: Adamas Reagents Ltd.

[0056] Methanol: Sinopharm Chemical Reagent Co., Ltd.

[0057] Toluene: Sinopharm Chemical Reagent Co., Ltd.

[0058] Chloroplatinic acid: Shanghai Myriel Chemical Technology Co., Ltd.

[0059] Isopropanol: Sinopharm Chemical Reagent Co., Ltd.

[0060] 1,3,5,7-Tetramethylcyclotetrasiloxane (D4H): Adamas Reagents Ltd.

[0061] Antioxidant: Irganox 168, manufactured by BASF.

[0062] Lubricant: PETS, pentaerythritol stearate, Lonza Corporation, USA.

[0063] Transesterification inhibitor: PGP, Quansheng Company.

[0064] Eugenol glycidyl ether (EPEU): 33 parts by weight of eugenol, 130 parts by weight of epichlorohydrin, and 1.2 parts by weight of tetrabutylammonium bromide were added to a three-necked flask equipped with a condenser and thermometer. The mixture was reacted at 85°C for 5 hours, then cooled to 40°C. 16 parts by weight of a 40wt% NaOH solution was added dropwise, and the reaction was continued for 4 hours. The precipitated NaCl was removed by filtration. An equal amount of dichloromethane was added, and the mixture was washed five times with water to obtain the organic phase. The phase was dehydrated with anhydrous magnesium sulfate, and excess epichlorohydrin was removed by rotary evaporation. Three times the amount of methanol was added to the crude product, and the mixture was recrystallized three times to obtain EPEU.

[0065] Organosilicon-modified eugenol glycidyl ether (SiEEP): 22 parts by mass of EPEU, 22 parts by mass of toluene, and 0.02 parts by mass of a 36 wt% isopropanol solution of chloroplatinic acid were added to a three-necked flask equipped with a condenser and a thermometer. The temperature was raised to 70°C, and 60 parts by mass of a 50 wt% toluene solution of tetramethylcyclotetrasiloxane (D4H) were added dropwise. The reaction was carried out for 20 hours, followed by rotary evaporation and drying in a vacuum oven at 85°C for 12 hours to obtain organosilicon-modified eugenol glycidyl ether.

[0066]

[0067] Performance tests are as follows:

[0068] Impact strength was tested according to ISO 179 standard. The sample size was 80*10*4mm and the notch depth was 2.0mm.

[0069] Bending strength was tested according to ISO 178, with a sample size of 80*10*4mm and a rate of 2mm / min.

[0070] Tensile strength was tested according to ISO 527, with a sample size of 170*10*4mm and a tensile rate of 50mm / min.

[0071] The flammability rating was tested according to UL-94, with a sample size of 130mm*13mm*1.5mm, and tested for vertical burning.

[0072] Examples 1-3 and Comparative Examples 1-4:

[0073] The material preparation process is as follows:

[0074] (1) Blending, extrusion and granulation: Polycarbonate resin, PET, tetramethylcyclotetrasiloxane, EPEU, SiEEP, etc. are mixed in a high-speed mixer according to the types and amounts of raw materials in Table 1. The mixture is added to the loss-in-weight feeder above the feed port of the screw extruder. The temperatures of zones 1-10 of the twin-screw extruder are controlled at 200℃, 220℃, 240℃, 250℃, 250℃, 250℃, 250℃, 240℃, and 235℃, respectively. The die head temperature is 230℃. The screw speed is controlled at 400 rpm. The mixture goes through blending, drawing, water cooling, air drying, pelletizing and drying processes to obtain the PC / PET composition.

[0075] Table 1. Formulations of Comparative Examples 1-4 and Examples 1-3

[0076]

[0077] Table 2 Performance comparison of Comparative Examples 1-4 and Examples 1-3

[0078] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Impact strength / KJ / m 2 ]] 42 40 60 65 65 80 100 Flexural Modulus / MPa 2200 2200 2400 2400 2300 2400 2600 Tensile Strength / MPa 52 53 65 66 60 69 75

[0079] Table 3 Comparison of vertical combustion performance between Comparative Examples 1-4 and Examples 1-3

[0080]

[0081] Note: Combustion rating V0 > V1 > V2 > NG.

[0082] By comparing the mechanical properties of Comparative Examples 1-4 and Examples 1-3, it can be found that the addition of EPEU can improve the strength of PC / PET alloys, meaning that the addition of chain extenders can improve the processing performance of PET. By comparing the impact of Comparative Examples 1-4 and Examples 1-3, it can be seen that EPEU chain extenders can improve the impact performance of materials, while adding a smaller amount of SiEEP chain extender significantly improves the impact performance, and the impact performance is further improved with increasing addition amount. By comparing the flammability ratings of Comparative Examples 1-4 and Examples 1-3, it can be seen that adding tetramethylcyclotetrasiloxane alone can improve the flame retardant effect of materials, but the addition of organosilicon-modified eugenol glycidyl ether chain extender can achieve better flame retardant performance with a smaller amount.

[0083] The above results demonstrate that adding organosilicon-modified eugenol glycidyl ether chain extender to PC / PET alloys can significantly improve the material's strength, toughness, and flame retardancy.

[0084] Those skilled in the art should understand that this invention is not limited to the above embodiments. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims.

Claims

1. A chain extender, with the following structural formula:

2. The method for preparing the chain extender according to claim 1, comprising the following steps: (1) Eugenol was reacted with epichlorohydrin to obtain eugenol glycidyl ether; (2) The eugenol glycidyl ether obtained in step (1) is reacted with tetramethylcyclotetrasiloxane to prepare organosilicon modified eugenol glycidyl ether.

3. The method according to claim 2, characterized in that, In step (1), a quaternary ammonium salt phase transfer catalyst is added, preferably one or more of benzyltriethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, and trioctylmethylammonium chloride; preferably, the amount of the phase transfer catalyst added is 3‰-8‰ of the mass of epichlorohydrin.

4. The method according to claim 2 or 3, characterized in that, In step (2), a platinum-based catalyst is added; preferably, one or more of chloroplatinic acid, platinum-carbon, and platinum are used; preferably, the amount of catalyst added in step (2) is 0.1‰-0.6‰ of the mass of tetramethylcyclotetrasiloxane.

5. A flame-retardant PC / PET alloy material, comprising the following raw materials in parts by weight: 30-80 parts by weight of PC; 10-60 parts by weight of PET; 0-15 parts by weight of the chain extender according to claim 1; Optionally, 0-5 parts by weight of processing aid.

6. The alloy material according to claim 5, characterized in that, Including the following parts by weight of raw materials: 50-80 parts by weight of PC; 10-40 parts by weight of PET; 0-10 parts by weight of the chain extender according to claim 1; Optionally, 0-5 parts by weight of processing aid.

7. The alloy material according to claim 5 or 6, characterized in that, The PC, under test conditions of 300℃ and 1.2kg, has a melt flow index of 3-65g / 10min, preferably 5-50g / 10min, and more preferably 7-35g / 10min.

8. The alloy material according to claim 5 or 6, characterized in that, The intrinsic viscosity of the PET is 0.58 dl / g-0.87 dl / g.

9. A method for preparing the flame-retardant PC / PET alloy material according to any one of claims 5-8, comprising the following steps: (a) Premixing: PC, PET, chain extender and optional processing aids are added to a mixer in proportion and stirred to obtain a premix; (b) Extrusion: The premixed material is extruded and granulated through a twin-screw extruder to obtain flame-retardant PC / PET alloy material.

10. The method according to claim 9, characterized in that, The conditions for step (b) include: the temperature of the conveying section of the twin-screw extruder is 210-240°C, the temperature of the plasticizing section is 230-270°C, the temperature of the metering section is 240-270°C, and the screw speed is 200-800 rpm.

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