EPP heat insulation buffer material for chip and preparation method of EPP heat insulation buffer material
By adding modified solid waste-aerogel composite material and compatibilizer to EPP material, a multi-level porous structure is formed, which solves the problems of insufficient thermal insulation performance and low compressive strength of EPP material, and achieves more efficient thermal insulation and buffering performance.
Patent Information
- Application Number
- CN202511231901.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2025-11-14
AI Technical Summary
Existing EPP materials have insufficient thermal insulation properties during chip transportation and storage, failing to effectively prevent heat transfer and thermal runaway risks, and their compressive strength and cushioning performance need to be improved.
By adding modified solid waste-aerogel composite materials, a nanoscale aerogel pore + micron-scale solid waste particle gap + macroscopic closed-cell structure is formed. Combined with ammonium molybdate impregnation and ultrasonic-assisted freeze drying treatment, the thermal insulation performance and compressive strength of EPP are improved. Furthermore, a gradient cell structure is formed by compatibilizers and foaming agents to enhance the buffering performance.
It significantly reduces the thermal conductivity of EPP, enhances compressive strength and cushioning performance, prevents thermal bridging effect, and improves thermal insulation efficiency and resistance to deformation.
Smart Images
Figure CN120944241A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chip materials technology, specifically to an EPP thermal insulation buffer material for chips and its preparation method. Background Technology
[0002] Proper packaging is crucial for ensuring the safety of chips during transportation and storage. EPP (Expanded Polypropylene) offers superior cushioning performance; its unique porous structure effectively absorbs and disperses impact forces. For example, when electronic products encounter bumps and collisions during express delivery, EPP packaging material can evenly distribute external impact forces throughout the material, significantly reducing the risk of damage to the internal electronic products. Furthermore, the closed-cell structure of EPP material gives it an extremely low thermal conductivity, effectively preventing heat transfer.
[0003] EPP insulated boxes can reduce insulation time in high-temperature summer environments to 50% of that in winter, and enhanced insulation performance can extend the stability of cold chain transportation. Meanwhile, new energy vehicle battery packs are temperature-sensitive, and improved EPP insulation performance can prevent the risk of thermal runaway.
[0004] Therefore, this invention aims to design an EPP thermal insulation buffer material for chips and a preparation method thereof to enhance the performance of EPP. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides an EPP thermal insulation buffer material for chips and its preparation method.
[0006] An EPP thermal insulation buffer material for chips, comprising the following components by weight percentage:
[0007] Antioxidant: 0.5-1%;
[0008] Foaming agent: 1-3%;
[0009] Compatibilizer: 4-6%;
[0010] Modified solid waste-aerogel composite material: 0.1-0.5%;
[0011] Polypropylene: Balance.
[0012] Furthermore, the preparation method of the modified solid waste-aerogel composite material is as follows:
[0013] Silica sol, modified solid waste powder, and a 5-6% polyvinyl alcohol solution were mixed at a solid-liquid ratio of 2-3g:1g:0.7-0.9ml and stirred at 60-70℃ for 20-30min. The resulting composite was washed with ethanol and aged at 55-75℃ for 20-40h to obtain an aerogel.
[0014] The aerogel was impregnated in a 0.1-0.15M ammonium molybdate aqueous solution at a solid-liquid ratio of 1g:15-25ml for 3-4 hours at a temperature of 35-40℃. After impregnation, the product was obtained by centrifugation. The product was placed in a tube furnace and a mixed gas of Ar / H2 with a volume ratio of 18-20:1 was introduced at a flow rate of 35-45mL / min. The temperature was increased to 550-600℃ at a rate of 1-3℃ / min and held for 1.5-2 hours. The product was then cooled to room temperature to obtain the surface-treated aerogel.
[0015] The surface-treated aerogel was subjected to ultrasonic-assisted freeze-drying with an ultrasonic power of 200-250W, a freezing temperature of -40 to -20℃, a freezing time of 24-36h, a drying temperature of -45 to -35℃, and a drying time of 30-35h, finally yielding a modified solid waste-aerogel composite material.
[0016] Description: By combining silica sol with modified solid waste powder, the material forms a structure of nanoscale aerogel pores + micron-scale solid waste particle gaps + macroscopic closed pores. Among them, the multi-level pores improve the compressive strength of EPP through crack deflection and energy dissipation mechanisms; the nanoscale pores block air convection, and the micron-scale pores extend the heat conduction path, resulting in a lower thermal conductivity than traditional EPP; ammonium molybdate impregnation and reduction treatment generate a MoO2 / Mo composite layer on the aerogel surface, which reduces heat radiation transfer and improves interfacial bonding energy to avoid thermal bridging effects; the composite material is subjected to ultrasonic-assisted freeze drying, which preserves the complete porous skeleton of the aerogel and forms a multi-level pore synergy with the foam structure of EPP, further blocking the heat transfer path and improving the thermal insulation efficiency.
[0017] Furthermore, the method for preparing the modified solid waste powder is as follows:
[0018] The emerging solid waste is crushed to 200-250 mesh, and then pyrolyzed at 400-700℃ for 4-7 hours at a rate of 8-10℃ / min to obtain pyrolyzed powder.
[0019] The pyrolysis powder, biphenyl hydrochloride, and chloroether resin are stirred and mixed at a mass ratio of 1:0.2-0.3:0.25 for 5-10 minutes to obtain a mixture. The mixture is then boiled in an aqueous H2O2 solution with a mass concentration of 1-2% at 45-55°C at a solid-liquid ratio of 1g:40-50ml for 10-11 hours, while ozone is blown in at a rate of 5-10mL / min.
[0020] The cooked mixture is filtered and dried at 105–110°C for 2–3 hours to obtain modified solid waste powder.
[0021] Explanation: The powder from the pyrolysis of emerging solid waste contains inorganic fibers or mineral phases. Its surface forms a porous structure through high-temperature pyrolysis. These micron-sized pores, together with the closed-cell bubbles of EPP itself, create a synergistic effect, significantly reducing the continuity of the heat conduction path. Biphenyl hydroquinone, as a crosslinking agent, works synergistically with chloroether resin to form an "anchoring layer" at the interface between the solid waste powder and EPP, thereby enhancing the interfacial bonding energy, effectively inhibiting crack propagation in EPP, improving compressive strength, and maintaining the elastic recovery rate of EPP. During the cooking process, the synergistic effect of ozone and H2O2 introduces polar groups such as hydroxyl and carboxyl groups onto the powder surface. These active sites are bonded to the EPP molecular chains through hydrogen bonds or chemical bonds, reducing interfacial thermal resistance and forming a gradient density structure, further enhancing the thermal insulation effect.
[0022] Furthermore, the emerging solid waste is a photovoltaic frame or a wind turbine blade.
[0023] Note: Glass fiber, carbon fiber and other reinforcing materials in photovoltaic frames or wind turbine blades, after being pyrolyzed, form micron-sized fibers that can serve as a reinforcing phase, significantly improving the buffering performance of EPP.
[0024] Furthermore, the method for preparing the silica sol is as follows:
[0025] A sodium silicate solution with a mass concentration of 10-20%, ethanol, and deionized water are mixed in a mass ratio of 1:1:3-4 to obtain a mixed solution. Sodium lignosulfonate is then added to the mixed solution at a liquid-to-solid ratio of 1 ml:0.1-0.2 g. After mixing for 10-11 hours, silica sol is obtained.
[0026] Explanation: Ethanol and deionized water are mixed to adjust the polarity of the sol, control the hydrolysis rate of sodium silicate, avoid agglomeration, and form a sol with excellent dispersibility. Sodium lignosulfonate, as an amphoteric surfactant, forms hydrogen / ionic bonds with Si-OH on the silica surface due to its polarity. The nonpolar aromatic rings are bonded to the polypropylene segments of EPP through van der Waals forces, significantly improving the interfacial bonding strength between the two phases and preventing the composite material from debonding under stress. Silica particles and sodium lignosulfonate form a "rigid-flexible composite reinforcing phase", which can improve the compression rebound rate of EPP and enhance its cushioning performance.
[0027] Furthermore, the compatibilizer is a hydrogenated styrene-butadiene block copolymer.
[0028] Note: Hydrogenated styrene-butadiene block copolymer has good heat resistance and elasticity, which can help enhance the cushioning and heat insulation properties of EPP.
[0029] Furthermore, the foaming agent is azodicarbonamide or azobisisobutyronitrile.
[0030] Note: The above-mentioned foaming agents give EPP its lightweight and porous properties, and these foaming agents are non-flammable and stable.
[0031] Furthermore, the antioxidant is any one of antioxidant 168, antioxidant 1010, and antioxidant PS802.
[0032] Note: The above antioxidants have excellent thermal stability.
[0033] A method for preparing an EPP thermal insulation buffer material for chips as described in any of the above claims includes the following steps:
[0034] S1. Polypropylene, modified solid waste-aerogel composite material, compatibilizer, antioxidant, and foaming agent are stirred at a speed of 1200-1800 r / min for 1-2 h to obtain a premix.
[0035] S2. The premixed material obtained in S1 is fed into a twin-screw extruder with a screw speed of 350-550 rpm, a feed temperature of 160-180℃, a mixing temperature of 185-205℃, and an extrusion temperature of 220-240℃. The material is then extruded and granulated to obtain EPP thermal insulation and cushioning material.
[0036] Compared with existing EPP materials, the beneficial effects of this invention are:
[0037] (1) The EPP material of the present invention is modified solid waste-aerogel composite material. Through the combination of silica sol and modified solid waste powder, the material forms a structure of nano-scale aerogel pores + micron-scale solid waste particle gaps + macro-closed pores. Among them, the multi-level pores improve the compressive strength of EPP through crack deflection and energy dissipation mechanisms; the nano-scale pores block air convection, and the micron-scale pores extend the heat conduction path, resulting in a lower thermal conductivity than traditional EPP; the ammonium molybdate impregnation and reduction treatment generate a MoO2 / Mo composite layer on the aerogel surface, which reduces heat radiation transfer on the one hand and improves the interfacial bonding energy on the other hand, avoiding the thermal bridge effect; the composite material is freeze-dried with ultrasonic assistance, which preserves the complete porous skeleton of the aerogel and forms a multi-level pore synergy with the foam structure of EPP, further blocking the heat transfer path and improving the thermal insulation efficiency.
[0038] (2) In this invention, the aerogel skeleton and solid waste particles form an interlocking structure to improve the compressive strength of EPP. The foaming agent and compatibilizer work together to form gradient pores, which improves the energy absorption effect and thus improves the buffering performance of EPP. Furthermore, the antioxidant is combined with the modified solid waste-aerogel composite material to improve the high-temperature deformation resistance of EPP. During the screw extrusion process, the feed temperature is relatively low to avoid premature decomposition of the modified solid waste-aerogel composite material. The temperature rises during mixing to trigger the initial decomposition of the foaming agent. The temperature rises further during extrusion to quickly form and solidify the skin layer. This gradient can form a biomimetic skeletal structure of "dense skin-porous core". Attached Figure Description
[0039] Figure 1 This is a comparison chart of the thermal conductivity results of Investigation 1 of this invention;
[0040] Figure 2 This is a comparison chart of the notched impact strength results of Investigation 1 of this invention;
[0041] Figure 3 This is a comparison chart of the thermal conductivity results of Investigation 2 of this invention;
[0042] Figure 4 This is a comparison chart of the notched impact strength results of Investigation 2 of this invention;
[0043] Figure 5 This is a comparison chart of the thermal conductivity results of Investigation 3 of this invention;
[0044] Figure 6 This is a comparison chart of the notched impact strength results of Investigation 3 of this invention;
[0045] Figure 7 This is a comparison chart of the thermal conductivity results of Investigation 4 of this invention;
[0046] Figure 8 This is a comparison chart of the notched impact strength results of Investigation 4 of this invention. Detailed Implementation
[0047] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.
[0048] Example 1: An EPP thermal insulation buffer material for chips, comprising the following components by weight percentage:
[0049] Antioxidant 168: 0.8%;
[0050] Foaming agent (azodicarbonamide): 2%;
[0051] Compatibilizer (hydrogenated styrene-butadiene block copolymer): 5%;
[0052] Modified solid waste-aerogel composite material: 0.3%;
[0053] Polypropylene: Balance;
[0054] The preparation method of the modified solid waste-aerogel composite material is as follows:
[0055] Silica sol, modified solid waste powder, and a 5.5% polyvinyl alcohol solution were mixed at a mass ratio of 2.5g:1g:0.8ml and stirred at 65℃ for 25min. The resulting composite was washed three times with ethanol and then aged at 65℃ for 30h to obtain an aerogel.
[0056] The aerogel was impregnated in a 0.12M ammonium molybdate aqueous solution at a solid-liquid ratio of 1g:20ml for 3.5h at a temperature of 38℃. After impregnation, the product was obtained by centrifugation. The product was placed in a tube furnace and a mixed gas of Ar / H2 with a volume ratio of 19:1 was introduced at a flow rate of 40mL / min. The temperature was increased to 575℃ at a rate of 2℃ / min and held for 1.8h. The product was then cooled to room temperature to obtain the surface-treated aerogel.
[0057] The surface-treated aerogel was subjected to ultrasonic-assisted freeze-drying with an ultrasonic power of 230W, a freezing temperature of -30℃, a freezing time of 30h, a drying temperature of -40℃, and a drying time of 32h, finally yielding a modified solid waste-aerogel composite material.
[0058] The method for preparing the modified solid waste powder is as follows:
[0059] Emerging solid waste (wind turbine blades) was crushed to 230 mesh and then pyrolyzed at 550℃ for 5.5 hours at a rate of 9℃ / min to obtain pyrolyzed powder.
[0060] The pyrolysis powder, biphenyl hydrochloride, and chloroether resin were stirred and mixed at a mass ratio of 1:0.25:0.25 for 8 minutes to obtain a mixture. The mixture was then boiled in a 1.5% H2O2 aqueous solution at 50°C with a solid-liquid ratio of 1g:45ml for 10.5 hours, while ozone was blown in at a rate of 8mL / min.
[0061] The cooked mixture was filtered to 250 mesh and dried at 108°C for 2.5 hours to obtain modified solid waste powder.
[0062] The method for preparing the silica sol is as follows:
[0063] A 15% sodium silicate solution, 50% ethanol, and deionized water were mixed in a mass ratio of 1:1:3.5 to obtain a mixed solution. Sodium lignosulfonate was then added to the mixed solution at a liquid-to-solid ratio of 1 ml:0.15 g. After mixing for 10.5 h, silica sol was obtained.
[0064] Example 2: The preparation method of the EPP thermal insulation buffer material for chips described in Example 1 includes the following steps:
[0065] S1. Polypropylene, modified solid waste-aerogel composite material, compatibilizer, antioxidant, and foaming agent are stirred at 1500 r / min for 1.5 h to obtain a premix.
[0066] S2. The premixed material obtained in S1 is fed into a twin-screw extruder with a screw speed of 400 rpm, a feed temperature of 170℃, a mixing temperature of 195℃, and an extrusion temperature of 230℃. The material is extruded and granulated to obtain EPP thermal insulation and cushioning material.
[0067] Example 3: This example differs from Example 1 in that it includes the following components by weight percentage:
[0068] Antioxidant 1010: 0.5%;
[0069] Foaming agent (azodicarbonamide): 1%;
[0070] Compatibilizer (hydrogenated styrene-butadiene block copolymer): 4%;
[0071] Modified solid waste-aerogel composite material: 0.5%;
[0072] Polypropylene: Balance.
[0073] Example 4: This example differs from Example 1 in that it includes the following components by weight percentage:
[0074] Antioxidant PS802: 1%;
[0075] Blowing agent (azobisisobutyronitrile): 3%;
[0076] Compatibilizer (hydrogenated styrene-butadiene block copolymer): 6%;
[0077] Modified solid waste-aerogel composite material: 0.1%;
[0078] Polypropylene: Balance.
[0079] Example 5: This example differs from Example 1 in that a 10% sodium silicate solution, ethanol, and deionized water are mixed in a mass ratio of 1:1:3 to obtain a mixed solution. Sodium lignosulfonate is then added to the mixed solution at a liquid-to-solid ratio of 1 ml:0.1 g. After mixing for 10 hours, silica sol is obtained.
[0080] Example 6: This example differs from Example 1 in that a 20% sodium silicate solution, ethanol, and deionized water are mixed in a mass ratio of 1:1:4 to obtain a mixed solution. Sodium lignosulfonate is then added to the mixed solution at a liquid-to-solid ratio of 1 ml:0.2 g. After mixing for 11 hours, silica sol is obtained.
[0081] Example 7: The difference between this example and Example 1 is that silica sol, modified solid waste powder, and a 5% polyvinyl alcohol solution are mixed at a solid-liquid ratio of 2g:1g:0.9ml and stirred at 60°C for 20min.
[0082] Example 8: The difference between this example and Example 1 is that silica sol, modified solid waste powder, and a 6% polyvinyl alcohol solution are mixed at a solid-liquid ratio of 3g:1g:0.7ml and stirred at 70°C for 30min.
[0083] Example 9: The difference between this example and Example 1 is that after washing, the aerogel was aged at 55°C for 20 hours.
[0084] Example 10: This example differs from Example 1 in that, after washing, the aerogel is aged at 75°C for 40 hours.
[0085] Example 11: The difference between this example and Example 1 is that the aerogel was immersed in a 0.1M ammonium molybdate aqueous solution at a solid-liquid ratio of 1g:15ml for 3 hours at a temperature of 35°C.
[0086] Example 12: The difference between this example and Example 1 is that the aerogel was immersed in a 0.15M ammonium molybdate aqueous solution at a solid-liquid ratio of 1g:25ml for 4 hours at a temperature of 40°C.
[0087] Example 13: The difference between this example and Example 1 is that the impregnated product is placed in a tube furnace and a mixed gas of Ar / H2 with a volume ratio of 18:1 is introduced at a gas flow rate of 35 mL / min, and the temperature is increased to 550°C at a rate of 1°C / min and held for 1.5 h.
[0088] Example 14: The difference between this example and Example 1 is that the impregnated product is placed in a tube furnace and a mixed gas of Ar / H2 with a volume ratio of 20:1 is introduced at a gas flow rate of 45 mL / min, and the temperature is increased to 600°C at a rate of 3°C / min and held for 2 hours.
[0089] Example 15: The difference between this example and Example 1 is that the ultrasonic power is 200W, the freezing temperature is -20℃, the freezing time is 24h, the drying temperature is -35℃, and the drying time is 30h.
[0090] Example 16: The difference between this example and Example 1 is that the ultrasonic power is 250W, the freezing temperature is -40℃, the freezing time is 36h, the drying temperature is -45℃, and the drying time is 35h.
[0091] Example 17: The difference between this example and Example 1 is that the emerging solid waste (wind turbine blades) is crushed to 200 mesh and then pyrolyzed at 400℃ for 4 hours at a rate of 8℃ / min to obtain pyrolyzed powder.
[0092] Example 18: The difference between this example and Example 1 is that the emerging solid waste (photovoltaic frame) is crushed to 250 mesh and then pyrolyzed at 700℃ for 7 hours at a rate of 10℃ / min to obtain pyrolyzed powder.
[0093] Example 19: The difference between this example and Example 1 is that the pyrolysis powder, biphenyl hydrochloride, and chloroether resin were stirred and mixed at a mass ratio of 1:0.2:0.25 for 5 minutes to obtain a mixture.
[0094] Example 20: The difference between this example and Example 1 is that the pyrolysis powder, biphenyl hydrochloride, and chloroether resin were stirred and mixed at a mass ratio of 1:0.3:0.25 for 10 minutes to obtain a mixture.
[0095] Example 21: This example differs from Example 1 in that the mixture is boiled in a 1% H2O2 aqueous solution at 45°C for 10 hours at a solid-liquid ratio of 1g:50ml, while ozone is blown in at 5mL / min.
[0096] Example 22: This example differs from Example 1 in that the mixture is boiled in a 2% H2O2 aqueous solution at 55°C for 11 hours at a solid-liquid ratio of 1g:40ml, while ozone is blown in at 10mL / min.
[0097] Example 23: The difference between this example and Example 1 is that the cooked mixture is filtered and dried at 105°C for 2 hours to obtain modified solid waste powder.
[0098] Example 24: The difference between this example and Example 1 is that the cooked mixture is filtered and dried at 110°C for 3 hours to obtain modified solid waste powder.
[0099] Example 25: This example differs from Example 2 in that polypropylene, modified solid waste-aerogel composite material, compatibilizer, antioxidant, and foaming agent are stirred at 1200 r / min for 1 h.
[0100] Example 26: The difference between this example and Example 2 is that polypropylene, modified solid waste-aerogel composite material, compatibilizer, antioxidant, and foaming agent are stirred at 1800 r / min for 2 h.
[0101] Example 27: The difference between this example and Example 2 is that the screw speed is 350 rpm, the feed temperature is 160°C, the mixing temperature is 205°C, and the extrusion temperature is 220°C.
[0102] Example 28: The difference between this example and Example 2 is that the screw speed is 550 rpm, the feed temperature is 180°C, the mixing temperature is 185°C, and the extrusion temperature is 240°C.
[0103] Experimental Example: The description of this experimental example is based on the scheme described in Example 2, and aims to illustrate the practical application effect of the present invention.
[0104] The thermal conductivity of the EPP prepared in each embodiment was tested according to the GB / T3139-2005 standard. The test was conducted three times and the average value of the results was taken.
[0105] The notched impact strength of the EPP prepared in each embodiment was tested according to the national standard GB / T1843-2008 "Determination of impact strength of plastic cantilever beam". The test was conducted three times and the average value of the results was taken.
[0106] Investigation 1: Investigate the effect of the component ratio of EPP thermal insulation buffer material on thermal conductivity and notched impact strength.
[0107] The difference between Comparative Example 1 and Example 1 is that no modified solid waste-aerogel composite material was added;
[0108] Depend on Figure 1 and Figure 2 The results analysis showed that, compared with Example 1, the raw materials lacked modified solid waste-aerogel composite material, so EPP lacked the structure of nano-scale aerogel pores + micron-scale solid waste particle gaps + macro-closed pores, resulting in increased cracks. The thermal conductivity and notched impact strength of EPP were significantly lower than those of Example 1, Example 3 to Example 4.
[0109] Comparing Examples 1 and 3-4, it can be seen that too little or too much modified solid waste-aerogel composite material will reduce the thermal conductivity and notched impact strength of EPP. Therefore, from a comprehensive perspective, the parameters of Example 1 are relatively better.
[0110] Investigation 2: Investigate the effect of the preparation of modified solid waste-aerogel composite materials on thermal conductivity and notched impact strength.
[0111] The difference between Comparative Example 2 and Example 1 is that no modified solid waste powder was added;
[0112] The difference between Comparative Example 3 and Example 1 is that the aerogel is not impregnated or heat-treated;
[0113] Depend on Figure 3 and Figure 4 Analysis of the results showed that, in Comparative Example 2, the modified solid waste-aerogel composite material lacked modified solid waste powder, which weakened the interfacial bonding energy between the modified solid waste-aerogel material and EPP, resulting in an increase in cracks. In Comparative Example 3, the lack of impregnation and heat treatment resulted in the absence of a MoO2 / Mo composite layer in the composite material, which weakened both the heat radiation transfer resistance and the interfacial bonding energy. Therefore, the thermal conductivity and notched impact strength of EPP in Comparative Example 2 and Comparative Example 3 were significantly lower than those in Examples 1 and 5 to 16.
[0114] Comparing Examples 1 and 5-16, it can be seen that too small or too large a proportion of sodium lignosulfonate, too small or too large a proportion of modified solid waste powder, too small or too large an aging parameter, too small or too large an impregnation parameter, too small or too large a heat treatment parameter, and too small or too large an ultrasonic freeze-drying parameter will reduce the thermal conductivity and notched impact strength of EPP. In Example 14, the heat treatment temperature was increased and the holding time was extended, and the performance was improved compared to Example 1, but the improvement was less than the increase in parameters. Therefore, from an economic point of view, the parameter effect of Example 1 is relatively better.
[0115] Inquiry 3: Investigate the effect of the preparation of modified solid waste on thermal conductivity and notched impact strength.
[0116] The difference between Comparative Example 4 and Example 1 is that cooking under an ozone atmosphere was not performed;
[0117] Depend on Figure 5 and Figure 6 The results analysis showed that, since ozone cooking was not performed in Control Example 4, no active sites such as polar groups such as hydroxyl and carboxyl groups were introduced into the powder surface, which increased the interfacial thermal resistance. Therefore, the thermal conductivity and notched impact strength of EPP in Control Example 4 were significantly lower than those in Examples 1 and 17 to 24.
[0118] Comparing Examples 1 and 17 to 24, it can be seen that excessively small or large pyrolysis parameters, excessively small or large proportion of pyrolysis powder, excessively small or large ozone cooking parameters, and excessively small or large drying parameters will all reduce the thermal conductivity and notched impact strength of EPP. Therefore, from a comprehensive perspective, the parameters of Example 1 are relatively better.
[0119] Investigation 4: Investigate the effect of the preparation of EPP thermal insulation buffer material on thermal conductivity and notched impact strength.
[0120] Depend on Figure 7 and Figure 8 The results analysis shows that in Examples 2 and 25 to 28, excessively small stirring parameters and excessively small or large screw extrusion parameters will reduce the thermal conductivity and notched impact strength of EPP. Therefore, from a comprehensive perspective, the parameter effect of Example 2 is relatively better.
Claims
1. An EPP thermal insulation buffer material for chips, characterized in that, By weight percentage, it includes the following components: Antioxidant: 0.5-1%; Foaming agent: 1-3%; Compatibilizer: 4-6%; Modified solid waste-aerogel composite material: 0.1-0.5%; Polypropylene: Balance.
2. The EPP thermal insulation buffer material for chips as described in claim 1, characterized in that, The preparation method of the modified solid waste-aerogel composite material is as follows: Silica sol, modified solid waste powder, and a 5-6% polyvinyl alcohol solution were mixed at a solid-liquid ratio of 2-3g:1g:0.7-0.9ml and stirred at 60-70℃ for 20-30min. The resulting composite was washed with ethanol and aged at 55-75℃ for 20-40h to obtain an aerogel. The aerogel was impregnated in a 0.1-0.15M ammonium molybdate aqueous solution at a solid-liquid ratio of 1g:15-25ml for 3-4 hours at a temperature of 35-40℃. After impregnation, the product was obtained by centrifugation. The product was placed in a tube furnace and a mixed gas of Ar / H2 with a volume ratio of 18-20:1 was introduced at a flow rate of 35-45mL / min. The temperature was increased to 550-600℃ at a rate of 1-3℃ / min and held for 1.5-2 hours. The product was then cooled to room temperature to obtain the surface-treated aerogel. The surface-treated aerogel was subjected to ultrasonic-assisted freeze-drying with an ultrasonic power of 200-250W, a freezing temperature of -40 to -20℃, a freezing time of 24-36h, a drying temperature of -45 to -35℃, and a drying time of 30-35h, finally yielding a modified solid waste-aerogel composite material.
3. The EPP thermal insulation buffer material for chips as described in claim 2, characterized in that, The method for preparing the modified solid waste powder is as follows: The emerging solid waste is crushed to 200-250 mesh, and then pyrolyzed at 400-700℃ for 4-7 hours at a rate of 8-10℃ / min to obtain pyrolyzed powder. The pyrolysis powder, biphenyl hydrochloride, and chloroether resin are stirred and mixed at a mass ratio of 1:0.2-0.3:0.25 for 5-10 minutes to obtain a mixture. The mixture is then boiled in an aqueous H2O2 solution with a mass concentration of 1-2% at 45-55°C at a solid-liquid ratio of 1g:40-50ml for 10-11 hours, while ozone is blown in at a rate of 5-10mL / min. The cooked mixture is filtered and dried at 105–110°C for 2–3 hours to obtain modified solid waste powder.
4. The EPP thermal insulation buffer material for chips as described in claim 3, characterized in that, The emerging solid waste refers to photovoltaic frames or wind turbine blades.
5. The EPP thermal insulation buffer material for chips as described in claim 2, characterized in that, The method for preparing the silica sol is as follows: A sodium silicate solution with a mass concentration of 10-20%, ethanol, and deionized water are mixed in a mass ratio of 1:1:3-4 to obtain a mixed solution. Sodium lignosulfonate is then added to the mixed solution at a liquid-to-solid ratio of 1 ml:0.1-0.2 g. After mixing for 10-11 hours, silica sol is obtained.
6. The EPP thermal insulation buffer material for chips as described in claim 1, characterized in that, The compatibilizer is a hydrogenated styrene-butadiene block copolymer.
7. The EPP thermal insulation buffer material for chips as described in claim 1, characterized in that, The foaming agent is azodicarbonamide or azobisisobutyronitrile.
8. The EPP thermal insulation buffer material for chips as described in claim 1, characterized in that, The emerging solid waste refers to photovoltaic frames or wind turbine blades.
9. The EPP thermal insulation buffer material for chips as described in claim 1, characterized in that, The antioxidant is any one of antioxidant 168, antioxidant 1010, and antioxidant PS802.
10. A method for preparing an EPP thermal insulation buffer material for chips as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Polypropylene, modified solid waste-aerogel composite material, compatibilizer, antioxidant, and foaming agent are stirred at a speed of 1200-1800 r / min for 1-2 h to obtain a premix. S2. The premixed material obtained in S1 is fed into a twin-screw extruder with a screw speed of 350-550 rpm, a feed temperature of 160-180℃, a mixing temperature of 185-205℃, and an extrusion temperature of 220-240℃. The material is then extruded and granulated to obtain EPP thermal insulation and cushioning material.