A pbe modified foamed material, a method for preparing the same and a foamed product

Abstract

The present application relates to the field of polymer foaming, and particularly to a PBE modified foaming material, a preparation method thereof and a foaming product. The preparation method of the PBE modified foaming material provided by the present application comprises the following steps: under the action of a chlorosulfonating agent, performing a chlorosulfonation reaction on pre-chlorinated PBE and an initiator to obtain the PBE modified foaming material; the chlorosulfonating agent is selected from one or more of sulfur dioxide, chlorine, sulfuryl chloride and chlorosulfonic acid. The PBE modified foaming material, i.e. the chlorosulfonated PBE material, prepared by the present application has substantially unchanged melt flow rate and no obvious decrease in molecular weight compared with the material before modification, and the mutual reaction of the sulfonyl groups in the molecular chain can form crosslinking and entanglement of the molecular chain, thereby improving the melt strength of the material and enabling the material to be applied in the field of foaming. In addition, due to the introduction of chlorine atoms and sulfonyl groups, the flame retardancy of the material is greatly improved, and the material can be applied as a flame-retardant foaming material.

Description

Technical Field

[0001] This invention relates to the field of polymer foaming, specifically to a PBE-modified foaming material, its preparation method, and foamed products. Background Technology

[0002] Polymer foam materials are materials containing countless air bubbles, and can also be considered a composite material with gas as filler. Due to their low density and excellent thermal and sound insulation properties, they are widely used in various fields of life, such as automotive parts, packaging, and construction. The polymer foaming process generally involves three stages: bubble nucleus formation, bubble nucleus expansion, and bubble fixation. Among these, the bubble nucleus expansion process is the key step that determines the quality of the foamed material. For foamed materials, the quality of foaming performance mainly depends on the melt strength of the matrix. If the melt strength is too low, the bubbles will merge or collapse during expansion, resulting in large bubbles and cross-bubbling. In severe cases, this can lead to melt rupture, causing gas escape and foaming failure. Therefore, improving the melt strength of the material is crucial for improving the quality of foamed materials. The melt strength mainly depends on the molecular weight and its distribution, as well as the entanglement of the molecular chains. The higher the molecular weight and the more entangled the molecular chains, the higher the melt strength of the material. Therefore, in the foaming process, samples with higher molecular weights are usually selected and grafted or crosslinked to improve the melt strength of the material, thereby achieving the desired foaming effect.

[0003] As a type of foaming material, propylene-based elastomers (PBE) possess high elasticity, toughness, and excellent processability. Their molecular chains consist of repeating units of isotactic polypropylene and randomly distributed ethylene, butene, etc. While PBE materials have higher melt strength than homopolymer polypropylene, crosslinking or grafting modification is necessary to meet the requirements of foaming processes. Patent CN 114181461A discloses a propylene-based elastomer foaming material and its preparation method, which improves the foaming performance of the composite material by adding crosslinking agents and crosslinking aids. However, although the introduction of crosslinking agents improves the melt strength of the material, residual crosslinking agents can cause excessive crosslinking in some areas, leading to uneven foaming. Patent 201110377655.7 discloses an ultra-high flowability propylene-based elastomer graft copolymer and its preparation method. This method uses peroxide to initiate the grafting of propylene-based elastomers. During the melt grafting process, numerous side reactions occur, and residual initiator leads to continuous degradation of the elastomer material, resulting in a significant decrease in molecular weight. Patent CN 104558425A discloses a propylene-based elastomer polymer grafted and modified using ultrasonic technology, avoiding the need for an initiator. However, ultrasonication induces shear degradation in the polymer, which also reduces the molecular weight of the sample, leading to a decrease in the melt strength of the material. Furthermore, the monomer insertion rate of the polymer obtained through grafting is not high, resulting in limited improvement in the melt strength of the material. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a PBE modified foaming material, its preparation method and foaming product. The foaming material provided by the present invention has high melt strength and high flame retardant properties, and can be applied to the preparation of foaming products with high foaming quality and high flame retardant properties.

[0005] This invention provides a method for preparing a PBE-modified foam material, comprising the following steps:

[0006] Under the action of chlorosulfonating agent, prechlorinated PBE and initiator are subjected to chlorosulfonation reaction to obtain PBE modified foam material;

[0007] The chlorosulfonating agent is selected from one or more of sulfur dioxide, chlorine, sulfonyl chloride, and chlorosulfonic acid.

[0008] The inventors of this application have creatively discovered that by subjecting pre-chlorinated PBE to a chlorosulfonation reaction, the introduction of sulfonyl groups into the PBE, under the initiation of an initiator, allows the sulfonyl groups to further react and form a cross-linked structure with disulfonyl groups, enhancing the entanglement of molecular chains and thus improving melt strength. Furthermore, the tertiary carbon atoms in the PBE backbone provide active sites for the insertion of sulfonyl groups, ensuring a high insertion rate. The introduction of high-chlorine atoms and sulfonyl groups also improves the flame-retardant properties of the material, enabling chlorosulfonated PBE to be applied to flame-retardant foam materials.

[0009] This invention involves a chlorosulfonation reaction of pre-chlorinated PBE and an initiator using a chlorosulfonating agent to obtain a PBE-modified foam material. Specifically, this invention involves a chlorosulfonation reaction of a pre-chlorinated PBE solution and an initiator using a chlorosulfonating agent to obtain a PBE-modified foam material. More specifically, this invention involves adding an initiator to a pre-chlorinated PBE solution, followed by the addition of a chlorosulfonating agent to conduct a chlorosulfonation reaction to obtain a PBE-modified foam material. In some embodiments of this invention, pre-chlorinated PBE and a solvent are mixed to obtain a pre-chlorinated PBE solution, an initiator is added to the pre-chlorinated PBE solution, followed by the addition of a chlorosulfonating agent to conduct a chlorosulfonation reaction to obtain a PBE-modified foam material.

[0010] The chlorosulfonating agent described in this invention is selected from one or more of sulfur dioxide, chlorine, sulfonyl chloride, and chlorosulfonic acid, preferably from a mixture of chlorine and sulfur dioxide. In one embodiment, the chlorosulfonating agent is selected from a mixture of chlorine and sulfur dioxide in a volume ratio of 1:(1-1.5). By controlling the ratio of chlorine to sulfur dioxide, this invention can control the insertion rate of chlorine atoms and sulfonyl groups, thereby regulating the melt strength of the material.

[0011] In this invention, the PBE chlorosulfonation process employs a batch solution method, achieving the introduction of chlorine atoms and sulfonyl groups through a free radical polymerization mechanism. The chlorosulfonation reaction temperature in this invention is 90–130°C, and the reaction time is 2–4 hours.

[0012] The pressure of the chlorosulfonating agent in the chlorosulfonation reaction is 0.1–0.4 MPa, preferably 0.2 MPa. This invention controls the amount of the chlorosulfonating agent used in the reaction system by controlling the pressure of the chlorosulfonating agent in the reaction system.

[0013] In the chlorosulfonation reaction described in this invention, the initiator is selected from one or more of azo initiators or peroxide initiators, specifically including one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, azoisobutylcyanoformamide, azobiscyclohexylformitrile, dimethyl azobisisobutyrate, azobisisobutyl ether amidine hydrochloride, dicumyl peroxide, benzoyl tert-butyl peroxide, benzoyl peroxide, and methyl ethyl ketone peroxide, preferably selected from azobisisobutyronitrile. The solvent for the pre-chlorinated PBE solution described in this invention is selected from one or more of carbon tetrachloride, 2,4,6-trichloromethane, 1,2-o-dichlorobenzene, 1,2-dichloroethane, and 1,1,1-trichloroethane.

[0014] The prechlorinated PBE of this invention is obtained by prechlorination of PBE, wherein the melt flow rate of the PBE is 0.5–25 g / 10 min, and the density of the PBE is 0.860 g / cm³. 3 ~0.890g / cm 3 In some embodiments of the present invention, the PBE is selected from one or more of propylene-ethylene, propylene-butene, propylene-hexene, and propylene-octene semi-crystalline copolymers.

[0015] Specifically, the prechlorinated PBE of the present invention is obtained by the following method: under the action of a prechlorination reagent, PBE and an initiator are subjected to a prechlorination reaction to obtain prechlorinated PBE; the prechlorination reagent is selected from one or more of chlorine, thionyl chloride, phosphorus trichloride and phosphorus pentachloride, preferably selected from chlorine.

[0016] More specifically, this invention involves a pre-chlorination reaction of a PBE solution and an initiator under the action of a pre-chlorination reagent to obtain pre-chlorinated PBE. Specifically, this invention mixes PBE and a solvent to obtain a PBE solution, then adds an initiator, followed by a pre-chlorination reagent to conduct a pre-chlorination reaction, resulting in pre-chlorinated PBE. In some embodiments of this invention, PBE and a solvent are added to a reaction vessel, and while purging with an inert gas, the mixture is heated to the temperature required for the pre-chlorination reaction to obtain a PBE solution. An initiator is then added, followed by a pre-chlorination reagent to conduct the pre-chlorination reaction, and then the addition of the pre-chlorination reagent is stopped to obtain pre-chlorinated PBE. This invention does not specifically limit the inert gas used; it can be any inert gas known to those skilled in the art, such as nitrogen. The reaction vessel used in this invention is a reaction vessel, specifically a 10-20L enamel-lined reaction vessel, preferably a 10L enamel-lined reaction vessel. The purging time with inert gas is 30-60 minutes, and the pressure of the inert gas is 0.1-0.35 MPa. The temperature of the prechlorination reaction described in this invention is 90–130°C, and the reaction time is 0.5–1 hour.

[0017] The pressure of the prechlorination reagent in the prechlorination reaction is 0.1-0.4 MPa; the present invention controls the amount of the prechlorination reagent used in the reaction system by controlling the pressure of the prechlorination reagent in the reaction system.

[0018] In the prechlorination reaction described in this invention, the initiator is selected from one or more of azo initiators or peroxide initiators, specifically including one or more of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, azoisobutylcyanoformamide, azobiscyclohexylformitrile, dimethyl azobisisobutyrate, azobisisobutyl ether amidine hydrochloride, dicumyl peroxide, benzoyl tert-butyl peroxide, benzoyl peroxide, and methyl ethyl ketone peroxide, preferably selected from azobisisobutyronitrile. The solvent of the PBE solution described in this invention is selected from one or more of carbon tetrachloride, 2,4,6-trichloromethane, 1,2-o-dichlorobenzene, 1,2-dichloroethane, and 1,1,1-trichloroethane.

[0019] The product obtained after the prechlorination reaction of this invention includes prechlorinated PBE and residual initiator. At this time, initiator and chlorosulfonation reagent can be directly added to the reaction system to carry out chlorosulfonation reaction to obtain PBE modified foam material. The residual initiator after the prechlorination reaction will continue to participate in the chlorosulfonation reaction. At this time, the total amount of initiator added again for chlorosulfonation reaction and the amount of initiator remaining in the prechlorination reaction can reach the amount of initiator required for chlorosulfonation reaction. In some embodiments of the present invention, the preparation method of the PBE modified foam material specifically includes the following steps: S1) Pre-chlorinating PBE and an initiator under the action of a pre-chlorination reagent; S2) Adding an initiator and a chlorosulfonating reagent to the product obtained in step S1) to perform a chlorosulfonation reaction to obtain the PBE modified foam material; wherein, the pressure of the pre-chlorination reagent in the pre-chlorination reaction in step S1) is 0.1-0.4 MPa; the mass of the initiator in step S1) accounts for 0.3 wt%-0.5 wt% of the mass of PBE in step S1); the pressure of the chlorosulfonating reagent in the chlorosulfonation reaction in step S2) is 0.1-0.4 MPa; and the mass of the initiator added in step S2) accounts for 0.5 wt%-1.5 wt% of the mass of PBE in step S1). The prechlorination reagent, PBE, the initiator in the prechlorination reaction, the chlorosulfonation reagent, and the initiator added in the chlorosulfonation reaction are all the same as described above and will not be repeated. The conditions for the prechlorination reaction and the chlorosulfonation reaction are also the same as described above and will not be repeated. In this invention, the initiator for the prechlorination reaction and the initiator for the chlorosulfonation reaction can be the same or different.

[0020] Following the chlorosulfonation reaction, this invention further includes deacidifying and purifying the resulting product to obtain a PBE-modified foaming material, i.e., chlorosulfonated PBE. Specifically, it includes passing an inert gas through the resulting product to remove acid, followed by adding water for negative pressure distillation purification to obtain the PBE-modified foaming material. In some embodiments of this invention, after the chlorosulfonation reaction, the resulting product is cooled to 40–50°C, and nitrogen gas is passed through it to remove acidic gases, yielding a product solution; then 1–2 L of deionized water is added to the product solution, stirred evenly, and then rotary evaporated using a rotary evaporator, heated to 60–90°C, and subjected to a negative pressure of 70–100 kPa to remove all organic solvents and most of the water. The solid is then dried in a vacuum drying oven to obtain the PBE-modified foaming material; the pressure of the inert gas in the deacidification step is 0.1–0.35 MPa. In some embodiments of this invention, the rotary evaporator used is model RE-52CS-2.

[0021] This invention provides a PBE-modified foaming material, namely chlorosulfonated PBE, which is prepared by the method described above. The chlorosulfonated PBE obtained by the above method has a chlorine content of 40 wt% to 65 wt% and a sulfur content of 2 wt% to 5 wt%.

[0022] This invention also provides a foamed product obtained by reacting a PBE-modified foaming material prepared by the above method with a free radical initiator. Specifically, the PBE-modified foaming material prepared by the above method and the free radical initiator are mixed evenly, added to a single-screw extruder, and extruded and granulated to obtain a foamed product, wherein the foamed product is high melt strength chlorosulfonated PBE particles. The amount of the free radical initiator used in this invention is 0.2wt% to 0.3wt% of the PBE-modified foaming material. The free radical initiator used in this invention is the same as the initiator used in the prechlorination reaction or the chlorosulfonation reaction, and will not be described again. In some embodiments of this invention, the foamed product is a sample made from the chlorosulfonated PBE particles. In some embodiments of this invention, the single-screw extruder is a JHE45 / 42 type, the operating temperature of the single-screw extruder is 130℃ to 160℃, preferably 150℃; the screw speed is 15 to 20 r / min, preferably 20 r / min.

[0023] This invention provides a PBE-modified foam material, its preparation method, and the foamed product thereof. The preparation method of the PBE-modified foam material provided by this invention includes the following steps: under the action of a chlorosulfonating agent, pre-chlorinated PBE and an initiator undergo a chlorosulfonation reaction to obtain the PBE-modified foam material; the chlorosulfonating agent is selected from one or more of sulfur dioxide, chlorine, sulfonyl chloride, and chlorosulfonic acid. The PBE-modified foam material prepared by this invention, namely chlorosulfonated PBE material, exhibits essentially unchanged melt flow rate and no significant decrease in molecular weight compared to the unmodified material. Furthermore, the mutual reaction of sulfonyl groups in the molecular chain can form cross-linking entanglements of the molecular chains, improving the melt strength of the material, making it suitable for application in the foaming field. In addition, the introduction of chlorine atoms and sulfonyl groups significantly improves the flame retardancy of the material, enabling its application as a flame-retardant foam material. Detailed Implementation

[0024] This invention discloses a PBE-modified foamed material, its preparation method, and the foamed product thereof. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0025] The raw materials used in the embodiments of this invention are as follows:

[0026] PBE uses ExxonMobil's Vistamaxx 3000 and Vistamaxx 6102 grades;

[0027] Carbon tetrachloride, using Aladdin reagent with a purity of 99%;

[0028] Chlorine gas comes from the chlor-alkali plant in Jingbo Petrochemical Boxing Industrial Park, with a water content of <45ppm;

[0029] Sulfur dioxide gas, sourced from Zibo Dijia Special Gases Co., Ltd., with a purity of 99.99%;

[0030] The initiator, 2,2'-azobisisobutyronitrile (AIBN), was a reagent with a purity of 99% from Aladdin.

[0031] The present invention will be further described below with reference to the embodiments:

[0032] Example 1

[0033] (1) Take 0.6 kg of PBE raw material (Vistamaxx 3000, MI 3.7 g / 10 min, density 0.873 g / cm³).3 Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0034] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0035] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1 into the polymerization reactor. Stop the reaction after 3h.

[0036] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0037] Example 2

[0038] (1) Take 0.6 kg of PBE raw material (Vistamaxx 3000, MI 3.7 g / 10 min, density 0.873 g / cm³). 3 Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0039] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0040] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1.2 into the polymerization reactor. Stop the reaction after 3h.

[0041] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0042] Example 3

[0043] (1) Take 0.6 kg of PBE raw material (Vistamaxx 3000, MI 3.7 g / 10 min, density 0.873 g / cm³). 3Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0044] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0045] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1.4 into the polymerization reactor. Stop the reaction after 3h.

[0046] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0047] Example 4

[0048] (1) Take 0.6 kg of PBE raw material (Vistamaxx 6102, MI 1.4 g / 10 min, density 0.862 g / cm³). 3 Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0049] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0050] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1 into the polymerization reactor. Stop the reaction after 3h.

[0051] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0052] Example 5

[0053] (1) Take 0.6 kg of PBE raw material (Vistamaxx 6102, MI 1.4 g / 10 min, density 0.862 g / cm³). 3Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0054] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0055] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1.2 into the polymerization reactor. Stop the reaction after 3h.

[0056] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0057] Example 6

[0058] (1) Take 0.6 kg of PBE raw material (Vistamaxx 6102, MI 1.4 g / 10 min, density 0.862 g / cm³). 3 Add 5 kg of carbon tetrachloride solvent to the reactor, heat to 110°C, purge with nitrogen gas, and dissolve for 60 min until the sample is completely dissolved. Nitrogen gas is continuously introduced during the dissolution process.

[0059] (2) Add 2.4g of initiator AIBN to the reactor, and introduce chlorine gas to carry out the prechlorination reaction. After reacting for 0.5h, turn off the chlorine gas.

[0060] (3) Add 6g of initiator and introduce a chlorine / sulfur dioxide mixed gas with a volume ratio of 1:1.4 into the polymerization reactor. Stop the reaction after 3h.

[0061] (4) Cool down to 40°C and introduce nitrogen gas into the polymerization reactor to remove acidic gases. Add 1.2L of deionized water to the product solution, stir evenly, and then perform rotary evaporation: heat to 85°C and a negative pressure of 90kPa to remove all organic solvents and some water. Place the solid in a vacuum drying oven to dry and obtain chlorosulfonated PBE.

[0062] Comparative Example 1

[0063] Commercial PBE sample Vistamaxx 3000.

[0064] Comparative Example 2

[0065] Commercial PBE sample Vistamaxx 6102.

[0066] The chlorosulfonated PBE samples obtained in Examples 1-6 were mixed evenly with a free radical initiator and then extruded and granulated in a single-screw extruder to obtain chlorosulfonated PBE particles with high melt strength. These particles were then prepared into the desired test strips. The obtained test strips and the samples from Comparative Examples 1 and 2 were subjected to structural and performance tests using the following methods:

[0067] Melt flow rate: determined according to the method specified in GB / T 3682-2000.

[0068] Chlorine content: determined according to the method specified in GB / T 9872.

[0069] Sulfur content: determined according to the method specified in GB 4497.

[0070] Melt strength (MS): determined according to the method specified in ISO 16790, at a test temperature of 230°C and a traction acceleration of 20 mm / s. 2 As the polymer melt is extruded downwards from the extruder die, it is pulled by two rollers moving in opposite directions on a balance beam until the melt bundle breaks.

[0071] Combustion performance: The limiting oxygen index of the foam material sample was tested according to the method specified in GB / T 2406.

[0072] The performance of each embodiment and comparative example product is summarized in Table 1:

[0073] Table 1

[0074]

[0075] In summary, this invention discloses a novel chlorosulfonated PBE material prepared by chlorosulfonation modification of PBE, and reveals the synthetic route of this material. Compared with the unmodified PBE, the melt flow rate of the chlorosulfonated PBE remains essentially unchanged, and the mutual reaction of the sulfonyl groups in the molecular chain can form cross-linking entanglements of the molecular chain, improving the melt strength of the material and enabling better application in the foaming field. By controlling the ratio of chlorine and sulfur dioxide, the insertion rate of chlorine atoms and sulfonyl groups can be controlled, thereby regulating the melt strength of the material. Furthermore, due to the introduction of chlorine atoms and sulfonyl groups, the flame retardancy of chlorosulfonated PBE is also significantly improved, enabling better application in flame-retardant foaming materials.

[0076] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing chlorosulfonated PBE material, characterized in that, Includes the following steps: S1) Under the action of a prechlorination reagent, PBE and an initiator undergo a prechlorination reaction; the prechlorination reagent is chlorine gas; the PBE is a propylene-ethylene semi-crystalline copolymer. S2) Add an initiator and a chlorosulfonating agent to the product obtained in step S1) to carry out a chlorosulfonation reaction to obtain chlorosulfonated PBE material; The chlorosulfonating agent is selected from a mixture of chlorine and sulfur dioxide in a volume ratio of 1:(1~1.5).

2. The method according to claim 1, characterized in that, The chlorosulfonation reaction is carried out at a temperature of 90~130℃ for a duration of 2 h~4 h.

3. The method according to claim 1, characterized in that, The temperature of the prechlorination reaction in step S1) is 90~130℃, and the time of the prechlorination reaction is 0.5 h~1 h.

4. The method according to claim 1, characterized in that, The initiator in step S1) and the initiator in step S2) are independently selected from one or more of azo initiators or peroxide initiators.

5. The method according to claim 1, characterized in that, The pressure of the prechlorination reagent in step S1) during the prechlorination reaction is 0.1~0.4 MPa; The amount of initiator used in step S1) is 0.3 wt% to 0.5 wt% of the amount of PBE used in step S1).

6. The method according to claim 5, characterized in that, The pressure of the chlorosulfonating agent in step S2) during the chlorosulfonation reaction is 0.1~0.4 MPa; The mass of the initiator added in step S2) is 0.5 wt% to 1.5 wt% of the mass of PBE used in step S1).

7. A chlorosulfonated PBE material, characterized in that, It is prepared by the method described in any one of claims 1 to 6.

8. A foamed product, characterized in that, It is obtained by reacting the chlorosulfonated PBE material prepared by any one of the methods in claims 1 to 6 with a free radical initiator.

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