An environmentally friendly expandable polystyrene bead and its preparation process

Abstract

This invention provides an environmentally friendly expandable polystyrene bead and its preparation process, belonging to the field of foaming material technology. The preparation process includes the following steps: S1, injecting 65.28g of deionized water into a reaction vessel, stirring, adding 0.13g of dispersant and 0.16g of composite stabilizer, dispersing for 20min, then adding 31.95g of styrene monomer and 0.3g of composite initiator, followed by the addition of pentane and SiO2 micelle composite to obtain a base solution; wherein the mass ratio of pentane to SiO2 micelle composite is 1:(0.2-0.3); the mass of pentane is 3.1%-3.2% of the mass of the base solution; S2, subjecting the base solution to stepwise heating at 86℃-140℃ with stirring, then stopping heating, continuing stirring, and allowing it to cool naturally to 40℃, then stopping stirring, with a total reaction time of 8.5-9.5h to obtain the reaction product; S3, discharging the material, washing the reaction product with warm water, filtering, and obtaining the environmentally friendly expandable polystyrene beads. This invention improves the average particle size of expandable polystyrene beads while reducing fine powder.

Description

Technical Field

[0001] This invention belongs to the field of foaming materials technology, specifically relating to an environmentally friendly expandable polystyrene bead and its preparation process. Background Technology

[0002] Expandable polystyrene is a novel polymer material produced by suspension polymerization of styrene monomer in a certain amount of pure water at a certain temperature, with the addition of an initiator, dispersant, stabilizer, and foaming agent. At a specific temperature, the initiator decomposes to generate free radicals that initiate the polymerization of styrene monomer. The active monomers formed during the chain initiation stage repeatedly and rapidly interact with the styrene monomer, resulting in chain growth. The reaction rate and molecular weight of polystyrene are controlled by adjusting the temperature and the amount of initiator. When the free monomer concentration decreases to a certain level, the reaction is essentially complete, and the product in the reactor is polystyrene. After impregnation with a foaming agent, expandable polystyrene is obtained.

[0003] In existing industrial production, a large amount of expandable polystyrene fine powder with a particle size of less than 0.6 mm is produced, meaning the fine powder ratio (the proportion of 0.6 mm expandable polystyrene fine powder) is high. This fine powder cannot be directly used for subsequent processing, and direct disposal would result in raw material waste; improper handling may form suspended dust, which not only pollutes the environment but also poses an explosion risk; while recycling requires putting it back into the reactor for polymerization, significantly increasing energy consumption (such as the repeated consumption of heating, stirring and other processes). Summary of the Invention

[0004] To address the problems existing in the background technology, the present invention provides an environmentally friendly expandable polystyrene bead and its preparation process, which improves the average particle size of the obtained expandable polystyrene beads while reducing the fine powder rate.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a process for preparing environmentally friendly expandable polystyrene beads, comprising the following steps:

[0006] S1. Inject 65.28g of deionized water into the reactor, stir, add 0.13g of dispersant and 0.16g of composite stabilizer, disperse for 20min, then add 31.95g of styrene monomer and 0.3g of composite initiator, followed by the addition of pentane and SiO2 micelle complex to obtain the base solution; wherein the mass ratio of pentane to SiO2 micelle complex is 1:(0.2-0.3); the mass of pentane is 3.1%-3.2% of the mass of the base solution;

[0007] S2. The base solution obtained in S1 is heated in steps from 86℃ to 140℃ and stirred. The small particles in the system harden. Then, the heating is stopped, stirring is continued, and the temperature is naturally cooled to 40℃. Stirring is then stopped. The total reaction time is 8.5-9.5 hours, and the reaction product is obtained.

[0008] S3. Discharge the product, wash the reaction product obtained in S2 with warm water, filter, and you will get environmentally friendly expandable polystyrene beads.

[0009] Furthermore, the preparation method of the SiO2 micelle complex is as follows:

[0010] A1. Dissolve poloxamer in deionized water, add sodium chloride, heat and stir until completely dissolved to obtain an amphiphilic micelle solution;

[0011] A2. Dissolve tetraethyl orthosilicate in a mixed solution of ethanol and tetrahydrofuran to obtain a homogeneous solution. Add the homogeneous solution dropwise to the amphiphilic micelle solution obtained in A1 at a rate of 1-2 mL / min. Stir (400-500 rpm) to achieve two-phase mixing. Use the hydrophobic core of the micelles to capture tetraethyl orthosilicate molecules to obtain a mixed solution.

[0012] A3. Add hydrochloric acid to the mixture obtained in A2, adjust the pH to 3-4, and react at 40-45℃ for 35-40h to promote the hydrolysis and condensation of tetraethyl orthosilicate in micelles to generate microporous SiO2, and obtain the reaction solution.

[0013] A4. The reaction solution obtained in A3 is placed into a dialysis bag (molecular weight cutoff 30kDa), mannitol is added to avoid particle aggregation, and the mixture is dialyzed with deionized water for 70-80 hours to remove unreacted tetraethyl orthosilicate, ethanol, tetrahydrofuran and free poloxamer. After pre-freezing at -50℃, it is vacuum dried to obtain SiO2 micelle complex.

[0014] Furthermore, in A1, the concentration of poloxamer in the amphiphilic micelle solution is 1-3 wt%, and the concentration of sodium chloride is 0.1-0.2 wt%.

[0015] Furthermore, in A2, the concentration of tetraethyl orthosilicate in the homogeneous solution is 5-8 wt%.

[0016] Furthermore, in A2, the mass ratio of tetraethyl orthosilicate to poloxamer in the mixture is 1:(3-4).

[0017] Furthermore, the composite stabilizer includes sodium dodecylbenzenesulfonate and polyvinyl alcohol.

[0018] Furthermore, the composite initiator includes tert-butyl perbenzoate and benzoyl peroxide.

[0019] Furthermore, the dispersant is magnesium sulfate.

[0020] Furthermore, in S2, the specific operation of the stepwise heating and stirring reaction is as follows: first, heat to 80℃ for pre-dispersion for 30 minutes, then heat to 86℃ and start timing for 1 hour; heat to 100℃ and react for 1 hour; heat to 110℃ and react for 1 hour; then heat to 120℃ and react for 1.5 hours; then heat to 140℃ and react and harden for 1.5 hours.

[0021] Secondly, the present invention provides an environmentally friendly expandable polystyrene bead, which is prepared by the above-described preparation method.

[0022] This application has the following beneficial effects:

[0023] The present invention introduces a SiO2 micelle composite into the preparation process of environmentally friendly expandable polystyrene beads, which is made by coating nano-SiO2 with poloxamer micelles; so that the average particle size of the final product, environmentally friendly expandable polystyrene beads, exceeds 2.77 mm and the fine powder rate is less than 0.48%.

[0024] In the use of SiO2 micelle complexes, on the one hand, after poloxamer micelles encapsulate SiO2, they anchor to the surface of styrene droplets through hydrophobic interactions, while SiO2 provides mechanical support, reducing bubble breakage; on the other hand, the micelle complexes delay the pentane release rate and extend the nucleation window, requiring more pentane to achieve the optimal foaming density. Thus, the synergistic effect of SiO2 micelle complexes requires a higher amount of pentane to maintain foaming stability, optimize the balance between fine powder ratio and foaming effect, and thereby achieve the effect of increasing the average particle size while reducing the fine powder ratio. Attached Figure Description

[0025] Figure 1 A comparison chart of the average particle size test data of the expandable polystyrene beads finally obtained in Examples 1-5 and Comparative Examples 1-7 of the present invention;

[0026] Figure 2 A comparison chart of the fine powder rate test data of the expandable polystyrene beads finally obtained in Examples 1-5 and Comparative Examples 1-7 of the present invention. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.

[0029] Example 1: The preparation method of SiO2 micelle complex is as follows:

[0030] A1. Poloxamer was dissolved in deionized water, sodium chloride was added, and the mixture was heated to 40°C and stirred at a constant speed of 280 r / min for 1 h until completely dissolved, yielding an amphiphilic micelle solution. The concentration of poloxamer in the amphiphilic micelle solution was 2 wt%, and the concentration of sodium chloride was 0.15 wt%. Poloxamer F-127 (60318ES60) was purchased from Yisheng Biotechnology (Shanghai) Co., Ltd.

[0031] A2. Tetraethyl orthosilicate was dissolved in a mixture of ethanol and tetrahydrofuran at a mass ratio of 1:8 to obtain a homogeneous solution. The concentration of tetraethyl orthosilicate in the homogeneous solution was 7 wt%. The homogeneous solution was added dropwise to the amphiphilic micelle solution obtained in A1 at a rate of 1.5 mL / min, and the mixture was stirred at a stirring speed of 450 r / min to achieve two-phase mixing. Tetraethyl orthosilicate molecules were captured by the hydrophobic micelle cores to obtain a mixed solution. The mass ratio of tetraethyl orthosilicate to poloxamer in the mixed solution was 1:3.5. The tetraethyl orthosilicate was purchased from Jinan Shuangying Chemical Co., Ltd.

[0032] A3. Add hydrochloric acid to the mixture obtained in A2 to adjust the pH to about 3.2, and react at 42℃ for 40 hours to promote the hydrolysis and condensation of tetraethyl orthosilicate in micelles to generate microporous SiO2, thus obtaining the reaction solution.

[0033] A4. The reaction solution obtained in A3 is placed into a dialysis bag (molecular weight cutoff 30kDa). 1.5wt% mannitol is added to the reaction solution to avoid particle aggregation. Dialyze with deionized water for 75h to remove unreacted tetraethyl orthosilicate, ethanol, tetrahydrofuran and free poloxamer. Then, it is pre-frozen at -50℃ and vacuum dried to obtain SiO2 micelle complex.

[0034] A process for preparing environmentally friendly expandable polystyrene beads includes the following steps:

[0035] S1. Inject 65.28g of deionized water into the reactor, start stirring, and add 0.13g of magnesium sulfate dispersant and 0.16g of composite stabilizer. The composite stabilizer is a mixture of sodium dodecylbenzenesulfonate and polyvinyl alcohol in a mass ratio of 3:1. After dispersing for 20 minutes, add 31.95g of styrene monomer and 0.3g of composite initiator. The composite initiator includes 0.23g of tert-butyl perbenzoate and 0.07g of benzoyl peroxide. Then add pentane and SiO2 micelle complex to obtain the base solution; wherein the mass ratio of pentane to SiO2 micelle complex is 1:0.25; the mass of pentane is 3.15% of the mass of the base solution. Sodium dodecylbenzenesulfonate (99%) was purchased from Jinan Zhuopu Chemical Technology Co., Ltd. Polyvinyl alcohol (viscosity 40.0-65.0) was purchased from Hefei Tianyi New Materials Co., Ltd. Styrene monomer (99%) was purchased from Jinan Zhengkang Chemical Co., Ltd. tert-butyl perbenzoate (CP-02) was purchased from Shanghai Bojing Chemical Co., Ltd. Benzoyl peroxide (99%) was purchased from Shandong Qiyun Chemical Technology Co., Ltd. Pentane (superior grade) was purchased from Xiamen Minghuiyang Chemical Co., Ltd.

[0036] S2. The base solution obtained in S1 was subjected to a stepwise heating and stirring reaction at 86℃-140℃. Specifically, the temperature was first raised to 80℃ for pre-dispersion for 30 minutes, then raised to 86℃ to reduce thermal shock, and the reaction was timed for 1 hour; the temperature was then raised to 100℃ and reacted for 1 hour; the temperature was raised to 110℃ and reacted for 1 hour; the temperature was then raised to 120℃ and reacted for 1.5 hours; finally, the temperature was raised to 140℃ and the reaction was allowed to harden for 1.5 hours. Small particles in the system hardened, then heating was stopped, stirring continued, and the system was allowed to cool naturally to 40℃ before stirring was stopped. The total reaction time was 8.9 hours, yielding the reaction product.

[0037] S3. Discharge the product and wash the reaction product obtained in S2 with warm water (around 35℃). Filter the product to obtain environmentally friendly expandable polystyrene beads.

[0038] Example 2: The difference between this example and Example 1 is that: a preparation process for environmentally friendly expandable polystyrene beads includes the following steps:

[0039] S1. Inject 65.28g of deionized water into the reactor, start stirring, and add 0.13g of magnesium sulfate dispersant and 0.16g of composite stabilizer. The composite stabilizer is a mixture of sodium dodecylbenzenesulfonate and polyvinyl alcohol in a mass ratio of 3:1. After dispersing for 20 minutes, add 31.95g of styrene monomer and 0.3g of composite initiator. The composite initiator includes 0.23g of tert-butyl perbenzoate and 0.07g of benzoyl peroxide. Then add pentane and SiO2 micelle complex to obtain the base solution; wherein the mass ratio of pentane to SiO2 micelle complex is 1:0.2; the mass of pentane is 3.1% of the mass of the base solution.

[0040] S2. The base solution obtained in S1 was subjected to a stepwise heating and stirring reaction at 86℃-140℃. Specifically, the temperature was first raised to 80℃ for pre-dispersion for 30 minutes, then raised to 86℃ and timed for 1 hour; the temperature was then raised to 100℃ and reacted for 1 hour; the temperature was raised to 110℃ and reacted for 1 hour; the temperature was then raised to 120℃ and reacted for 1.5 hours; finally, the temperature was raised to 140℃ and the reaction was allowed to harden for 1.5 hours. Small particles in the system hardened, then heating was stopped, stirring continued, and the system was allowed to cool naturally to 40℃ before stirring was stopped. The total reaction time was 8.8 hours, yielding the reaction product.

[0041] S3. Discharge the product, wash the reaction product obtained in S2 with warm water, filter, and you will get environmentally friendly expandable polystyrene beads.

[0042] Example 3: The difference between this example and Example 1 is that: a preparation process for environmentally friendly expandable polystyrene beads includes the following steps:

[0043] S1. Inject 65.28g of deionized water into the reactor, start stirring, and add 0.13g of magnesium sulfate dispersant and 0.16g of composite stabilizer. The composite stabilizer is a mixture of sodium dodecylbenzenesulfonate and polyvinyl alcohol in a mass ratio of 3:1. After dispersing for 20 minutes, add 31.95g of styrene monomer and 0.3g of composite initiator. The composite initiator includes 0.23g of tert-butyl perbenzoate and 0.07g of benzoyl peroxide. Then add pentane and SiO2 micelle complex to obtain the base solution; wherein the mass ratio of pentane to SiO2 micelle complex is 1:0.3; the mass of pentane is 3.2% of the mass of the base solution.

[0044] S2. The base solution obtained in S1 was subjected to a stepwise heating and stirring reaction at 86℃-140℃. Specifically, the temperature was first raised to 80℃ for pre-dispersion for 30 minutes, then raised to 86℃ and timed for 1 hour; the temperature was then raised to 100℃ and reacted for 1 hour; the temperature was raised to 110℃ and reacted for 1 hour; the temperature was then raised to 120℃ and reacted for 1.5 hours; finally, the temperature was raised to 140℃ and the reaction was allowed to harden for 1.5 hours. Small particles in the system hardened, then heating was stopped, stirring continued, and the system was allowed to cool naturally to 40℃ before stirring was stopped. The total reaction time was 9.1 hours, yielding the reaction product.

[0045] S3. Discharge the product, wash the reaction product obtained in S2 with warm water, filter, and you will get environmentally friendly expandable polystyrene beads.

[0046] Example 4: The difference between this example and Example 1 is that the preparation method of the SiO2 micelle complex is as follows:

[0047] A1. Dissolve poloxamer in deionized water, add sodium chloride, heat to 40°C, and stir at a constant speed of 280 r / min for 1 h until completely dissolved to obtain an amphiphilic micelle solution. The concentration of poloxamer in the amphiphilic micelle solution is 1 wt%, and the concentration of sodium chloride is 0.1 wt%.

[0048] A2. Tetraethyl orthosilicate was dissolved in a mixture of ethanol and tetrahydrofuran in a mass ratio of 1:8 to obtain a homogeneous solution. The concentration of tetraethyl orthosilicate in the homogeneous solution was 5 wt%. The homogeneous solution was added dropwise to the amphiphilic micelle solution obtained in A1 at a rate of 1 mL / min, and the mixture was stirred at a stirring speed of 400 r / min to achieve two-phase mixing. Tetraethyl orthosilicate molecules were captured by the hydrophobic cores of the micelles to obtain a mixed solution. The mass ratio of tetraethyl orthosilicate to poloxamer in the mixed solution was 1:3.

[0049] A3. Add hydrochloric acid to the mixture obtained in A2 to adjust the pH to about 3.2, and react at 42℃ for 40 hours to promote the hydrolysis and condensation of tetraethyl orthosilicate in micelles to generate microporous SiO2, thus obtaining the reaction solution.

[0050] A4. The reaction solution obtained in A3 is placed into a dialysis bag (molecular weight cutoff 30kDa), and 1wt% mannitol is added to the reaction solution to avoid particle agglomeration. Dialyze with deionized water for 70h to remove unreacted tetraethyl orthosilicate, ethanol, tetrahydrofuran and free poloxamer. Then, it is pre-frozen at -50℃ and vacuum dried to obtain SiO2 micelle complex.

[0051] Example 5: The difference between this example and Example 1 is that the preparation method of the SiO2 micelle complex is as follows:

[0052] A1. Dissolve poloxamer in deionized water, add sodium chloride, heat to 40°C, and stir at a constant speed of 280 r / min for 1 h until completely dissolved to obtain an amphiphilic micelle solution. The concentration of poloxamer in the amphiphilic micelle solution is 3 wt%, and the concentration of sodium chloride is 0.2 wt%.

[0053] A2. Tetraethyl orthosilicate was dissolved in a mixture of ethanol and tetrahydrofuran in a mass ratio of 1:8 to obtain a homogeneous solution. The concentration of tetraethyl orthosilicate in the homogeneous solution was 8 wt%. The homogeneous solution was added dropwise to the amphiphilic micelle solution obtained in A1 at a rate of 2 mL / min, and the mixture was stirred at a stirring speed of 500 r / min to achieve two-phase mixing. Tetraethyl orthosilicate molecules were captured by the hydrophobic cores of the micelles to obtain a mixed solution. The mass ratio of tetraethyl orthosilicate to poloxamer in the mixed solution was 1:4.

[0054] A3. Add hydrochloric acid to the mixture obtained in A2 to adjust the pH to about 3.2, and react at 42℃ for 40 hours to promote the hydrolysis and condensation of tetraethyl orthosilicate in micelles to generate microporous SiO2, thus obtaining the reaction solution.

[0055] A4. The reaction solution obtained in A3 is placed into a dialysis bag (molecular weight cutoff 30kDa), and 2wt% mannitol is added to the reaction solution to avoid particle aggregation. Dialyze with deionized water for 80h to remove unreacted tetraethyl orthosilicate, ethanol, tetrahydrofuran and free poloxamer. Then, it is pre-frozen at -50℃ and vacuum dried to obtain SiO2 micelle complex.

[0056] Comparative Example 1: The difference between this comparative example and Example 1 is that the SiO2 micelle complex was removed, and the mass of pentane was 2.4% of the mass of the base solution.

[0057] Comparative Example 2: The difference between this comparative example and Example 1 is that the SiO2 micelle complex was removed, and the mass of pentane was 2.7% of the mass of the base solution.

[0058] Comparative Example 3: The difference between this comparative example and Example 1 is that the SiO2 micelle complex was removed (the mass of pentane is 3.15% of the mass of the base solution, the same as in Example 1).

[0059] Comparative Example 4: The difference between this comparative example and Example 1 is that the SiO2 micelle complex is replaced with poloxamer (the mass of pentane is 3.15% of the mass of the base solution, the same as in Example 1).

[0060] Comparative Example 5: The difference between this comparative example and Example 1 is that the SiO2 micelle complex is replaced with nano-SiO2 (the mass of pentane is 3.15% of the mass of the base solution, the same as in Example 1).

[0061] Comparative Example 6: The difference between this comparative example and Example 1 is that the mass of pentane is 2.4% of the mass of the base solution.

[0062] Comparative Example 7: The difference between this comparative example and Example 1 is that the mass of pentane is 2.7% of the mass of the base solution.

[0063] Experimental Example: ① A digital camera was used to photograph the expandable polystyrene beads obtained in Examples 1-5 and Comparative Examples 1-7. The photos were measured and the data were statistically analyzed to obtain the average particle size. ② The expandable polystyrene beads obtained in Examples 1-5 and Comparative Examples 1-7 were weighed and recorded as Mtotal. The expandable polystyrene beads obtained in Examples 1-5 and Comparative Examples 1-7 were sieved using a sieve with a sieve with a pore size of 0.6 mm. Fine powder with a particle size less than 0.6 mm was sieved out, weighed, and recorded as Mfine. The fine powder rate was calculated as: Fine powder rate = Mfine / Mtotal.

[0064] Experimental results: see Table 1.

[0065]

[0066] Results Analysis: Analysis of Examples 1-5, combined with data from Table 1 and... Figures 1-2 As can be seen, the average particle size of the environmentally friendly expandable polystyrene beads obtained by the present invention (Examples 1-5) exceeds 2.77 mm, and the fine powder rate is less than 0.48%.

[0067] Analysis of Example 1 and Comparative Examples 1-7, combined with data from Table 1 and Figures 1-2 By comparing Comparative Examples 1, 2, and 3, it can be seen that as the mass percentage of pentane in the base solution increases from 2.4% to 3.15%, the average particle size of the final expandable polystyrene beads continues to increase, while the fine powder ratio first decreases and then increases.

[0068] Comparing Comparative Examples 3, 4, and 5, it is evident that adding either poloxamer or nano-SiO2 alone leads to a further increase in the fine powder ratio of the final expandable polystyrene beads when the pentane content in the base solution is 3.15% by mass. This indicates that the relationship between the pentane content in the base solution and the fine powder ratio shifts to the left. This is because adding nano-SiO2 alone acts as a heterogeneous nucleation site, promoting uniform nucleation of pentane bubbles, reducing bubble coalescence, and lowering the fine powder ratio; that is, a small amount of SiO2 can significantly improve the nucleation efficiency, shifting the pentane content threshold corresponding to the lowest fine powder ratio to the left. Using poloxamer alone promotes the dispersion of pentane into smaller bubbles due to micelle formation, lowering the pentane content threshold; that is, poloxamer alone allows pentane to achieve uniform foaming at a lower content, shifting the lowest fine powder ratio point to the left.

[0069] Comparing Comparative Examples 6 and 7 with Example 1, it can be seen that with the addition of the SiO2 micelle composite of the present invention, as the mass percentage of pentane in the base solution increases from 2.4% to 3.15%, the average particle size of the final expandable polystyrene beads maintains a continuous increasing trend, while the fine powder ratio continuously decreases. This indicates that the relationship curve between the mass percentage of pentane in the base solution and the fine powder ratio shifts to the right. This is because, on the one hand, after poloxamer micelles encapsulate SiO2, they are anchored to the surface of styrene droplets through hydrophobic interactions, while SiO2 provides mechanical support, reducing bubble breakage; on the other hand, the micelle composite delays the pentane release rate, prolonging the nucleation window period, requiring more pentane to achieve the optimal foaming density. Thus, the synergistic effect of the SiO2 micelle composite requires a higher amount of pentane to maintain foaming stability and optimize the balance between the fine powder ratio and the foaming effect.

[0070] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0071] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A process for the preparation of environmentally friendly expandable polystyrene beads, characterized in that, It comprises the following steps: S1, inject 65.28g deionized water into a reaction kettle, stir, add 0.13g dispersant and 0.16g composite stabilizer, disperse for 20min, then add 31.95g styrene monomer and 0.3g composite initiator, and then add pentane and SiO2 micelle complex to obtain a base solution; wherein the mass ratio of pentane and SiO2 micelle complex is 1: (0.2-0.3); the mass of pentane is 3.1%-3.2% of the mass of the base solution; S2, the base solution obtained in S1 is subjected to stepwise heating and temperature rising at 86-140℃, stirring reaction, then heating is stopped, stirring is continued, and natural cooling to 40℃ is carried out, then stirring is stopped, and the total reaction time is 8.5-9.5h to obtain a reaction product; S3, discharge, wash the reaction product obtained in S2 with warm water, filter, and then the environmentally friendly expandable polystyrene beads are obtained; The preparation method of the SiO2 micelle complex is as follows: A1, dissolve poloxamer in deionized water, add sodium chloride, heat and stir to obtain an amphiphilic micelle solution; A2, dissolve tetraethyl orthosilicate in a mixed solution of ethanol and tetrahydrofuran to obtain a homogeneous solution, drop the homogeneous solution into the amphiphilic micelle solution obtained in A1, and stir to obtain a mixed solution; A3, add hydrochloric acid to the mixed solution obtained in A2 to adjust the pH to 3-4, and react at 40-45℃ for 35-40h to obtain a reaction solution; A4, pack the reaction solution obtained in A3 into a dialysis bag, add mannitol, dialyze with deionized water for 70-80h, pre-freeze at-50℃, and then vacuum dry to obtain the SiO2 micelle complex.

2. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, In A1, the concentration of poloxamer in the amphiphilic micelle solution is 1-3wt%, and the concentration of sodium chloride is 0.1-0.2wt%.

3. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, In A2, the concentration of tetraethyl orthosilicate in the homogeneous solution is 5-8wt%.

4. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, In A2, the mass ratio of tetraethyl orthosilicate to poloxamer in the mixed solution is 1: (3-4).

5. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, The composite stabilizer comprises sodium dodecyl benzene sulfonate and polyvinyl alcohol.

6. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, The composite initiator comprises tert-butyl perbenzoate and benzoyl peroxide.

7. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, The dispersant is magnesium sulfate.

8. The process for preparing environmentally friendly expandable polystyrene beads according to claim 1, characterized in that, In S2, the specific operation of stepwise heating and temperature rising and stirring reaction is as follows: first, pre-disperse at 80℃ for 30min, then react for 1h at 86℃; then react for 1h at 100℃; then react for 1h at 110℃; then react for 1.5h at 120℃; and then react for 1.5h at 140℃ for hardening.

9. An environmentally friendly expandable polystyrene bead, characterized by, The preparation process of the environmentally friendly expandable polystyrene beads is prepared by using the preparation process of the environmentally friendly expandable polystyrene beads according to any one of claims 1-8.

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