Environment-friendly PPE / PS alloy material as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly PPE / PS alloy material as well as a preparation method and application thereof. The environment-friendly PPE / PS alloy material is prepared from the following raw materials in parts by weight: 15-84.98% of functionalized MPPE resin; 5 to 30% of polystyrene resin; 10 to 40% of flame-retardant glass fiber; 0.01 to 10% of a flame retardant; 0.01-2% of a synergistic flame retardant; and 0-3% of other auxiliary agents. The PPE / PS alloy material prepared by the invention has excellent mechanical properties, processability and flame retardant property, can be used for replacing steel with plastic for the upper cover of the energy storage battery, and has important significance for the light weight of the energy storage battery and the development of an energy storage technology.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, and in particular to an environmentally friendly PPE / PS alloy material and a preparation method and application thereof. Background Art

[0002] Energy storage technology refers to the technology that converts energy into a storable form and releases it when needed. Energy storage technology can play an important role in balancing supply and demand in the power system, improving the utilization rate of renewable energy, and coping with energy peak and valley differences. Energy storage technology is mainly divided into: lithium-ion batteries, pump energy storage, compressed air energy storage, dye battery technology, and supercapacitors. Among them, lithium-ion battery energy storage technology accounts for 94.2%, which is absolutely dominant. The future development trend of energy storage technology is mainly focused on improving energy density, reducing costs, improving safety, and realizing intelligence and digitalization.

[0003] The upper cover of lithium battery energy storage is an important component to protect the battery cell. It needs to have good high temperature resistance, corrosion resistance, flame retardancy and other characteristics. Commonly used upper cover materials are aluminum alloy and steel alloy. The "plastic instead of steel" upper cover of energy storage batteries can achieve a weight reduction of more than 40%, which is of great significance for the lightweighting of energy storage batteries. Polyphenylene ether (PPE) has excellent mechanical strength, stress relaxation resistance, creep resistance, heat resistance, water resistance, water vapor resistance, and dimensional stability, but polyphenylene ether has poor fluidity, a small processing window, and stress cracking. Polystyrene (PS) is an amorphous polymer with good fluidity and low water absorption. It is a plastic that is easy to form and process. The PPE / PS alloy material takes into account the flame retardancy, mechanical properties and processing properties of PPE and PS.

[0004] Chinese patent CN112745591A relates to a flame-retardant high-rigidity PS / PPE composite material and its preparation method and application. The flame-retardant high-rigidity PS / PPE composite material provided by the present invention adopts continuous long glass fiber and specific flame retardant synergist and flame retardant to synergize, and adjusts the glass fiber retention length D90, and the flame retardant grade can reach above 5VB under thin thickness conditions; through the synergistic effect of glass fiber and coupling agent, the material has high rigidity, toughness and heat resistance, high bending strength, bending modulus, notched impact strength and heat deformation temperature. Chinese patent CN114479420A develops a halogen-free flame-retardant PPO / HIPS composite material, and the selected reinforcing fiber is a fiber material surface-modified by a silane coupling agent as a substrate, and the surface is modified by functionalized POSS. Compared with the conventionally used alkali-free glass fiber, the addition of reinforcing fiber to the PPO / HIPS composite material of the present invention has a significant improvement effect on the mechanical properties of the material. Chinese patent CN114231015A discloses a PPE alloy material with arc resistance, electric trace resistance and high flame retardancy and its preparation method, providing an environmentally friendly PPE composite alloy material, which is resistant to oil, strong acid and strong alkali, and can be suitable for high temperature and high humidity or low temperature freezing conditions, and still ensures that it has long aging resistance, electric trace resistance, arc resistance and high flame retardancy, which can meet the product requirements of any industry for this performance. The currently disclosed patents realize the flame retardancy of PPE by physically blending flame retardants, which usually requires a high amount of flame retardant to achieve flame retardancy. The poor compatibility of flame retardants with resins has a greater impact on mechanical properties. To achieve the "plastic instead of steel" of energy storage battery cover materials, it is necessary to meet the flame retardancy while also requiring the material to have high mechanical properties. The research that takes into account both the mechanical properties and flame retardancy of PPE materials is of great significance. Summary of the invention

[0005] In order to fill the gap in the prior art, the present invention provides an environmentally friendly PPE / PS alloy material and a preparation method and application thereof. The PPE / PS alloy material is prepared by formula design, and the PPE / PS alloy material prepared by the method takes into account both flame retardant properties and mechanical properties, and can be applied to the performance requirements of materials for the use conditions of energy storage battery top covers.

[0006] The present invention is achieved through the following technical solutions:

[0007] An environmentally friendly PPE / PS alloy material comprises the following raw materials in parts by weight:

[0008]

[0009] The functionalized MPPE resin is a functionalized modified PPE resin, the weight average molecular weight of the PPE resin is 20000-60000, and the melt flow rate (test conditions: 280°C, 5kg) is 0.5-30g / 10min. The functionalized modification of PPE is prepared in two steps: first, a carboxyl modified PPE resin is prepared by reacting butyl lithium and carbon dioxide in anhydrous toluene solvent; secondly, the carboxyl modified PPE resin is further subjected to an acylation reaction, and the prepared functionalized MPPE resin has a terminal ester content of ≥60mmol / kg and a structural formula as follows:

[0010]

[0011] The polystyrene resin may be one or more of high impact polystyrene, general purpose polystyrene, SBS resin, etc., with a density of 1.04-1.06 g / cm3, a refractive index of 1.5-1.7, and a weight average molecular weight of 50000-200000. The present invention gives priority to HIPS.

[0012] The flame retardant glass fiber has an alkali content of less than 0.8%, a volume density of 0.6-0.8g / cm3, a single fiber diameter of 7-13μm, a short cut length of 2-5mm, a moisture content of ≤0.05%, and a bio-based epoxy phosphate solution is sprayed on the glass fiber surface for sizing treatment, and the mass fraction of the sizing agent is greater than 0.3%. The mass fraction of the flame retardant in the bio-based epoxy phosphate solution is 1%-10%, and part of the monomers of the epoxy phosphate are derived from biomass conversion, which is a bio-based material, and the structural formula is as follows:

[0013]

[0014] The flame retardant is a halogen-free phosphorus-containing flame retardant, which can be one or more of triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, tris(2,4,6-trimethylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphate, tris(2,6-di-tert-butylphenyl) phosphate, resorcinol bis(diphenyl phosphate), hydroquinone bis(diphenyl phosphate), bisphenol A-bis(diphenyl phosphate), resorcinol bis(2,6-di-tert-butylphenyl phosphate) or hydroquinone bis(2,6-dimethylphenyl phosphate). The present invention gives priority to bisphenol A bis(diphenyl phosphate).

[0015] The synergistic flame retardant is prepared by coating the surface of praseodymium rubidium oxide with bio-based diepoxyphenyl phosphate. Praseodymium rubidium oxide is a compound composed of praseodymium and rubidium, and its chemical formula is (Pr, Rb)2O3, which is a white or light yellow powder; the bio-based diepoxyphenyl phosphate coats the surface of praseodymium rubidium oxide by chemical bonds; wherein the bio-based diepoxyphenyl phosphate is prepared by the following reaction:

[0016]

[0017] The other auxiliary agents may be one or more of antioxidants, lubricants, and colorants.

[0018] The method for preparing the environmentally friendly PPE / PS alloy material comprises the following steps:

[0019] (1) Weigh various dried raw materials according to the formula ratio; mix the functionalized MPPE resin, polystyrene resin, flame retardant, and other additives uniformly by a high-speed mixer, and set aside; weigh the reinforcement according to the ratio, and set aside;

[0020] (2) The resin and additive mixed raw material are added through the main feeding port of a twin-screw extruder, and the filler is added from the side feeding port of the twin-screw extruder. After melt extrusion, granulation, drying and other processes, the PPE / PS alloy material is obtained.

[0021] The above-mentioned PPE / PS alloy material can be applied to the upper cover of energy storage batteries.

[0022] The advantage of the present invention is that the PPE / PS alloy material is prepared by formula design to meet the performance requirements of the material for the "plastic instead of steel" of the energy storage battery cover. According to the structural characteristics and flame retardant principle of the PPE / PS alloy material, the flame retardant is loaded on the surface of the glass fiber to prepare the flame retardant glass fiber, and the bio-based diepoxyphenyl phosphate is surface coated with praseodymium rubidium oxide to prepare the synergistic flame retardant. Compared with simple physical blending, the compatibility of the components of the formula system is increased, and a better flame retardant efficiency is obtained. The same flame retardant effect can greatly reduce the amount of flame retardant added. In the formula design of the present invention, functionalized MPPE resin is selected, and the resin can achieve better compatibility with glass fiber and flame retardant, and the prepared alloy material has better mechanical properties and flame retardant properties. The flame retardant selected by the present invention is partly bio-based and belongs to a halogen-free flame retardant. The source of the flame retardant monomer and the environmental protection of the flame retardant when the flame retardant is heated or burned are more advantageous.

[0023] The beneficial effects of the present invention are:

[0024] 1) The surface of the glass fiber selected by the present invention is loaded with a flame retardant, and the surface of the glass fiber is sizing treated by spraying a bio-based epoxy phosphate flame retardant solution on the surface of the glass fiber. During the processing of the alloy material, the flame retardant is uniformly dispersed in the resin along with the glass fiber. Compared with a separate component, the flame retardant loaded on the surface of the glass fiber can increase the dispersion of the flame retardant in the resin on the one hand, and on the other hand, it can block the "wick effect" of the glass fiber during the combustion process, thereby increasing the flame retardant efficiency of the flame retardant during the combustion process. Compared with simple physical blending, the amount of flame retardant added can be greatly reduced to achieve the same flame retardant effect.

[0025] 2) The synergistic flame retardant of the present invention is prepared by coating the surface of a compound containing praseodymium and rubidium rare earth elements with bio-based diepoxyphenyl phosphate. Rare earth elements have good heat absorption properties, absorb a large amount of heat during the combustion process, and reduce the combustion rate. Rare earth elements can react with free radicals, hydroxyl groups and other active substances in the material to produce non-flammable compounds. Rare earth elements can also promote carbonization reactions and increase the flame retardant properties of the material. Bio-based diepoxyphenyl phosphate itself has flame retardant properties. Compared with simple physical blending, coating the rare earth compound increases the synergistic effect of the two and increases the flame retardant efficiency. At the same time, the coating increases the compatibility of the rare earth compound with the resin, so that the PPE / PS alloy material has more excellent mechanical properties.

[0026] 3) The functionalized MPPE resin contains ester groups at the end. The functional modification of the end groups can increase the compatibility of glass fiber, flame retardant and resin, thereby increasing the mechanical properties of the alloy material.

[0027] 4) Some monomers of bio-based diepoxyphenyl phosphate are derived from bio-based materials and are halogen-free flame retardants. The flame retardant itself and the gas released when heated or burned are more environmentally friendly.

[0028] 5) The PPE / PS alloy material prepared by the present invention can achieve excellent flame retardant effect with a small amount of flame retardant added, and the material has excellent mechanical properties and processing properties, which meets the performance requirements of the energy storage battery cover for the material, and realizes the "plastic instead of steel" of the energy storage battery cover, which is of great significance for the lightweight of the energy storage battery.

[0029] The above beneficial effects achieve excellent mechanical properties, processing properties and flame retardant properties of the PPE / PS alloy material. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and intentions to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] The embodiments and comparative examples of the present invention use the following materials, but are not limited to the following materials:

[0032] Functionalized MPPE resin, commercially available;

[0033] HIPS, the Taiwanese trade name is HP825T, produced by Formosa Chemical Corporation;

[0034] PPE, trade name LXN040, produced by Nantong Xingchen Synthetic Materials Co., Ltd.;

[0035] Flame retardant glass fiber, homemade;

[0036] Glass fiber, trade name ECS306HR, produced by Chongqing International Composite Materials Co., Ltd.;

[0037] Flame retardant BDP, produced by Zhejiang Wansheng Co., Ltd.;

[0038] Synergistic flame retardant, homemade;

[0039] Praseodymium rubidium oxide, commercially available;

[0040] Processing aid. Product name LYSI-100E, produced by Chengdu Silike Technology Co., Ltd.

[0041] Antioxidant 1010, hindered phenol antioxidant, commercially available;

[0042] Antioxidant 9228, phosphite antioxidant, commercially available;

[0043] Masterbatch, trade name XP6581A, produced by Cabot;

[0044] Preparation methods of Examples 1-6 and Comparative Examples 1-6:

[0045] Preparation method of PPE / PS alloy material

[0046] (1) Weigh various dried raw materials according to the formula ratio; mix the functionalized MPPE resin, polystyrene resin, flame retardant, and other additives uniformly by a high-speed mixer, and set aside; weigh the reinforcement according to the ratio, and set aside;

[0047] (2) The resin and additive mixed raw material are added through the main feeding port of a twin-screw extruder, and the filler is added from the side feeding port of the twin-screw extruder. After melt extrusion, granulation, drying and other processes, the PPE / PS alloy material is obtained.

[0048] Preparation of PPE / PS alloy material test specimens:

[0049] The above materials were dried in a forced air drying oven at 120° C. for 4 hours and then injection molded into standard specimens at an injection molding temperature of 280-330° C. The prepared mechanical properties specimens were conditioned in a standard laboratory environment (23° C., 50% RH) for 24 hours before testing.

[0050] Test methods for each performance index:

[0051] Tensile properties: According to ISO 527 method, sample size: 170*10*4mm, test speed 5mm / min.

[0052] Bending properties: According to ISO 178 method, sample size: 80*10*4mm, test speed 2mm / min.

[0053] Notched impact performance: According to ISO 179 method, sample size: 80*10*4mm.

[0054] Heat deformation temperature: According to ISO 75 method, sample size: 80*10*4, test condition: 1.8MPa. Flame retardant performance: According to UL94 method, sample size: 127*12.7*1.6mm.

[0055] Table 1: Composition and properties of PPE / PS alloy materials in Examples 1-6 and Comparative Examples 1-6

[0056]

[0057] It can be seen from the results of the embodiments and comparative examples in Table 1 that the introduction of flame-retardant glass fiber and synergistic flame retardant in the formula design can improve the flame retardant properties and mechanical properties of PPE / PS alloy materials. It can be seen from Examples 1-3 and Comparative Examples 1-2 that flame-retardant glass fiber is helpful for improving flame retardant properties compared with conventional glass fiber. The amount of flame retardant added in the same flame retardant formula is small, and the mechanical properties will also be improved. The synergistic flame retardant has less effect on mechanical properties than the same amount of untreated praseodymium rubidium oxide, and has higher flame retardant efficiency. It can be seen from Examples 1, 3 and 5 that the present invention is applicable to different material grades. It can be seen from Examples 1, 3 and 6 that functionalized MPPE increases the mechanical properties and flame retardant properties of alloy materials compared with conventional resins, because the functional modification of the terminal groups can increase the compatibility of glass fiber, flame retardant and resin. The PPE / PS alloy material prepared by the present invention has excellent mechanical properties, processing properties and flame retardant properties, and can be used as the first material for "plastic instead of steel" in energy storage batteries, which is of great significance to the lightweighting of energy storage batteries.

Claims

1. An environmentally friendly PPE / PS alloy material, characterized by: According to the following raw material composition by weight:

2. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The functionalized MPPE resin is a functionalized modified PPE resin, the weight average molecular weight of the PPE resin is 20000-60000, and the melt flow rate is 0.5-30g / 10min. The functionalized modification of PPE is prepared in two steps: first, a carboxyl modified PPE resin is prepared by reacting butyl lithium and carbon dioxide in anhydrous toluene solvent; secondly, the carboxyl modified PPE resin is further acylated, and the prepared functionalized MPPE resin has a terminal ester content of ≥60mmol / kg and a structural formula as follows:

3. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The polystyrene resin is selected from one or more of high impact polystyrene, general-purpose polystyrene, and SBS resin, with a density of 1.04-1.06 g / cm 3 , refractive index: 1.5-1.7, weight average molecular mass: 50000-200000.

4. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The polystyrene resin is high impact polystyrene.

5. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The glass fiber has an alkali content of less than 0.8% and a volume density of 0.6-0.8 g / cm 3 , monofilament fiber diameter: 7-13μm, short cut length: 2-5mm, moisture content ≤0.05%, the glass fiber surface is sizing treated by spraying a bio-based epoxy phosphate solution on the glass fiber surface, and the mass fraction of the sizing agent is greater than 0.3%.

6. The environmentally friendly PPE / PS alloy material according to claim 5, characterized in that: The mass fraction of flame retardant in bio-based epoxy phosphate solution is 1%-10%. Some monomers of epoxy phosphate are derived from biomass conversion and are a kind of bio-based material. The structural formula is as follows:

7. The environmentally friendly PPE / PS alloy material according to claim 5, characterized in that: The preparation of the flame retardant glass fiber comprises the following steps: (1) soaking the glass fiber in a mixed solution consisting of a silane coupling agent and an aqueous solution of ethylene glycol, wherein the silane coupling agent is aminosilane or the like, and the mass fraction of the silane coupling agent in the mixed solution is 15-25%, adjusting the pH of the solution, and performing a silane coupling agent modification treatment to obtain a silane coupling agent modified glass fiber; (2) The silane coupling agent modified glass fiber is immersed in a bio-based epoxy phosphate solution for modification, wherein the mass fraction of the bio-based epoxy phosphate is 0.7-1.5%, the solvent can be tetrahydrofuran, ether, acetone or butanone, the temperature is 50-100°C, the time is 10-20h, and after filtering, washing and drying, a flame retardant glass fiber is obtained.

8. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The flame retardant is a halogen-free phosphorus-containing flame retardant, which can be one or more of triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, tris(2,4,6-trimethylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphate, tris(2,6-di-tert-butylphenyl) phosphate, resorcinol bis(diphenyl phosphate), hydroquinone bis(diphenyl phosphate), bisphenol A-bis(diphenyl phosphate), resorcinol bis(2,6-di-tert-butylphenyl phosphate) or hydroquinone bis(2,6-dimethylphenyl phosphate).

9. The environmentally friendly PPE / PS alloy material according to claim 8, characterized in that: The flame retardant is bisphenol A bis(diphenyl phosphate).

10. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The synergistic flame retardant is prepared by coating the surface of praseodymium rubidium oxide with bio-based diepoxyphenyl phosphate. Praseodymium rubidium oxide is a compound composed of praseodymium and rubidium, and its chemical formula is (Pr, Rb)2O3, which is a white or light yellow powder; the bio-based diepoxyphenyl phosphate coats the surface of praseodymium rubidium oxide by chemical bonds; wherein the bio-based diepoxyphenyl phosphate is prepared by the following reaction:

11. The environmentally friendly PPE / PS alloy material according to claim 10, characterized in that: The preparation of the synergistic flame retardant comprises the following steps: (1) adding praseodymium rubidium oxide into deionized water and stirring with ultrasonic waves to obtain a praseodymium rubidium oxide dispersion; (2) dissolving bio-based diepoxyphenyl phosphate in anhydrous ethanol to obtain a bio-based diepoxyphenyl phosphate-ethanol solution, then adding the bio-based diepoxyphenyl phosphate-ethanol solution to a praseodymium rubidium oxide dispersion under stirring conditions, heating to 50-80° C. for reaction for 0.5-4 hours, and then cooling to room temperature to obtain a slurry; the weight ratio of praseodymium rubidium oxide to bio-based diepoxyphenyl phosphate is 100:4-10; (3) filtering the white slurry to obtain a filter cake, washing and drying the filter cake to obtain the synergistic flame retardant.

12. The environmentally friendly PPE / PS alloy material according to claim 1, characterized in that: The other auxiliary agents are selected from one or more of antioxidants, lubricants and colorants.

13. The method for preparing the environmentally friendly PPE / PS alloy material according to any one of claims 1 to 12, characterized in that: The following steps are involved: (1) Weigh various dried raw materials according to the formula ratio; mix the functionalized MPPE resin, polystyrene resin, flame retardant, and other additives uniformly by a high-speed mixer, and set aside; weigh the reinforcement according to the ratio, and set aside; (2) The resin and additive mixed raw material are added through the main feeding port of a twin-screw extruder, and the filler is added from the side feeding port of the twin-screw extruder. After melt extrusion, granulation, drying and other processes, the PPE / PS alloy material is obtained.

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