Sulfur-rich polymer elastomer and preparation method thereof

Abstract

The invention discloses a sulfur-rich polymer elastomer. The sulfur-rich polymer elastomer with high strength and high toughness is prepared from industrial waste S and monomers PEGDA and ENB through anti-vulcanization. The invention also discloses a preparation method of the sulfur-rich polymer elastomer. The invention solves the problems of low strength and poor performance of the sulfur-rich polymer elastomer material prepared from industrial wastes in the prior art.

Description

Technical Field

[0001] This invention belongs to the field of elastomer materials technology, and relates to sulfur-rich polymer elastomers, as well as methods for preparing the aforementioned sulfur-rich polymer elastomers. Background Technology

[0002] The advent of desulfurization has provided a broad pathway for producing functional polymers from industrial byproduct elemental sulfur. Sulfur is widely available and inexpensive, and various methods have been proposed to directly produce sulfur-rich polymers from waste sulfur, including the reaction of thiols, diiodobenzene, and elemental sulfur, as well as the multi-component polymerization of sulfur with other molecules. This reaction is simple, efficient, and solvent-free, making full use of waste from the oil and gas industry and turning waste into treasure. Currently, sulfur-rich polymers have achieved admirable results, demonstrating excellent performance in various applications, such as flame-retardant materials, Li-S batteries, infrared thermal imaging materials across the entire visible light range, and self-healing materials. However, relatively poor mechanical properties limit their further development. Therefore, optimizing the thermal properties of desulfurized polymers and endowing them with certain mechanical properties is essential.

[0003] The main method to improve the mechanical properties of sulfur-rich polymers is through the use of different crosslinking agents. Initially, only two-component polymerization reactions were used, but the resulting materials often had low strength. Later, with the introduction of a third component, the material properties were significantly improved. The prior art, "Yan, P., Wang, H., Dodd, L. Jet et al. Processable crosslinked terpolymers made from elemental sulfur with wide range of thermal and mechanical properties. Commun Mater 4, 89 (2023)," discloses terpolymers copolymerized from PEG (n = 2.8, 10.2, or 13), TATA, and elemental sulfur to obtain polymers with a wide range of glass transition temperatures (-43℃ to 45℃). These polymers, by blending with crosslinking agents with different material ratios and chain lengths, produce materials with good mechanical properties. The drawback of this technique, or the deficiency relative to this invention, is that although a wide Tg polymer material is obtained by adjusting the material ratio and linear chain length, the prepared material does not exhibit strong tensile strength and elongation at break.

[0004] The existing technology "P. Yan, W. Zhao, B. Zhang, L. Jiang, S. Petcher, JASmith, DJ Parker, AI Cooper, J. Lei, T. Hasell. Inverse vulcanized polymers with shape memory, enhanced mechanical properties, and vitrimer behavior. Angew. Chem. Int. Ed. 2020, 59, 13371" also discloses the preparation of a hydroxyl-containing linear prepolymer by reverse vulcanization of S with Span 80, and then the preparation of an elastomer polymer with tensile strength of 0.14-20.17 MPa and elongation at break of 11.85%-51.20% by introducing isocyanate and crosslinking it. The drawback of this technology, or its deficiency relative to the present invention, is that although the material has a tensile strength of 20.17 MPa, it does not combine high strength with high flexibility. Whether using a new crosslinking agent or blending two different crosslinking agents, the rigid modulus of sulfur-rich polymers can be reduced from high to low, but the strength remains low. This means that the polymer becomes harder or softer, but the strength is not high, reducing the usability of the material. Summary of the Invention

[0005] One objective of this invention is to provide sulfur-rich polymer elastomers that solve the problems of low strength and poor performance in existing technologies that use industrial waste to prepare sulfur-rich polymer elastomer materials.

[0006] Another object of the present invention is to provide a method for preparing sulfur polymer elastomers.

[0007] The technical solution adopted in this invention is a sulfur-rich polymer elastomer, which includes the preparation of a high-strength and high-toughness sulfur-rich polymer elastomer by reverse vulcanization using industrial waste S and monomers PEGDA and ENB.

[0008] The invention is further characterized in that,

[0009] The raw materials, by weight percentage, consist of: 10wt%-90wt% polyethylene glycol diacrylate (PEGDA), 10wt%-90wt% ethylene-bis(norbornene) (ENB), and 30wt%-70wt% elemental sulfur. The resulting terpolymer is named "aS-b(PEGDA)". c -ENB d "a" and "b" represent the mass percentage of sulfur and the mass percentage of the crosslinking agent, respectively, while "c" and "d" represent the mass percentage of two different crosslinking agents.

[0010] Another technical solution adopted in this invention is a method for preparing sulfur-rich polymer elastomers, which is specifically implemented according to the following steps:

[0011] Step 1: Weigh out the following three monomers according to their mass ratio: polyethylene glycol diacrylate (PEGDA), ethylene-imide norbornene (ENB), and S.

[0012] Step 2: Add sulfur (S) and catalyst to a round-bottom flask, rotate the magnetic stirrer evenly, and heat until the sulfur is fully melted. After the sulfur has fully melted for 10 minutes, slowly add polyethylene glycol diacrylate (PEGDA) and ethylene-methylnorbornene (ENB) dropwise to the round-bottom flask and stir to react fully. After the reaction is complete, pour the polymer into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer. Place the prepolymer in a vacuum drying oven to cure.

[0013] Step 3: The sample obtained in Step 2 is prepared by hot pressing followed by cold pressing using a flat vulcanizing machine to obtain S-PEGDA-ENB elastomer.

[0014] The invention is further characterized in that,

[0015] The structures of the two different organic comonomers PEGDA and ENB in ​​step 1 are as follows:

[0016] Where n = 2.

[0017] In step 2, the amount of catalyst used is 1 wt% to 5 wt% of the total mass of the three comonomers.

[0018] The catalyst in step 2 is zinc diethyldithiocarbamate.

[0019] In step 2, the heating reaction temperature is 100-180℃, and the heating reaction time is 0.5-8h.

[0020] In step 2, the temperature of the vacuum drying oven is 100-150℃, and the curing time is 6-24h.

[0021] In step 3, the hot-pressing temperature is 150℃-230℃, and the hot-pressing time is 1min-15min.

[0022] The cold pressing time in step 3 is 1 min to 15 min.

[0023] The beneficial effects of this invention are as follows: The sulfur-rich polymer elastomer of this invention selects sulfur (S) and three monomers, PEGDA and ENB, and prepares a high-strength, high-toughness sulfur-rich polymer elastomer by adjusting the material ratio of the three components. Different glass transition temperatures of the elastomer can be achieved by adjusting the material ratio, reaction time, curing time, and hot pressing. The structure and properties of the polymer are characterized using different methods and techniques. This invention's method for preparing high-molecular-weight, high-strength, and high-toughness sulfur-rich polymer elastomers using PEGDA, ENB, and S not only further improves the tensile properties of sulfur-rich polymers but also uses low-cost raw materials for polymerization, and the preparation process is simple and easy to implement; it has significant implications for the further application of sulfur-rich polymer elastomers. Attached Figure Description

[0024] Figure 1 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y ) 1 HNMR comparison chart;

[0025] Figure 2 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y FT-IR comparison chart;

[0026] Figure 3 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). 50％ -ENB 50％ Raw material and product comparison chart;

[0027] Figure 4 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y Comparison chart of XRD and S XRD;

[0028] Figure 5 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y GPC spectrum;

[0029] Figure 6 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). 50％ -ENB 50％ XPS full spectrum;

[0030] Figure 7 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). 50％ -ENB 50％ XPS C1s spectrum;

[0031] Figure 8 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). 50％ -ENB 50％ XPS S2p spectrum;

[0032] Figure 9 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y DSC comparison chart;

[0033] Figure 10 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y TGA comparison chart;

[0034] Figure 11 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). 50％ -ENB 50％ Stress-strain curve;

[0035] Figure 12 The present invention relates to sulfur-rich polymer elastomer 50S-50 (PEGDA). x -ENB y Stress-strain curve comparison diagram. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0037] This invention relates to a sulfur-rich polymer elastomer, prepared via reverse vulcanization using industrial waste S and readily available, inexpensive monomers PEGDA and ENB, resulting in a high-strength, high-toughness polymer elastomer. The raw materials, by weight percentage, comprise: 10wt%-90wt% polyethylene glycol diacrylate (PEGDA), 10wt%-90wt% ethylenedibornene (ENB), and 30wt%-70wt% elemental sulfur. The resulting terpolymer is named "aS-b(PEGDA)". c -ENB d "a" and "b" represent the mass percentage of sulfur and the mass percentage of the crosslinking agent, respectively, while "c" and "d" represent the mass percentage of two different crosslinking agents.

[0038] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0039] Step 1: Weigh out the following three monomers according to their mass ratio: polyethylene glycol diacrylate (PEGDA), ethylene-imide norbornene (ENB), and S.

[0040] The structures of the two different organic comonomers, PEGDA and ENB, are as follows:

[0041] Where n = 2.

[0042] Step 2: Add sulfur and catalyst to a round-bottom flask, rotate the magnetic stir bar evenly, and heat until sulfur is fully melted; after sulfur has been fully melted for 10 minutes, slowly add polyethylene glycol diacrylate (PEGDA) and ethylene-methylnorbornene (ENB) dropwise to the round-bottom flask, and stir to react fully.

[0043] The catalyst used is 1wt%-5wt% of the total mass of the three comonomers, and the catalyst is zinc diethyldithiocarbamate; the heating reaction temperature is 100-180℃, and the heating reaction time is 0.5-8h. After the reaction is completed, the polymer is poured into a silicone mold and allowed to cool naturally to room temperature to obtain a prepolymer. The prepolymer is then placed in a vacuum drying oven for curing; the temperature of the vacuum drying oven is 100-150℃, and the curing time is 6-24h.

[0044] Step 3: The sample obtained in Step 2 is processed using a flat vulcanizing machine by hot pressing followed by cold pressing to obtain the S-PEGDA-ENB elastomer. The hot pressing temperature is 150℃-230℃, the hot pressing time is 1min-15min, and the cold pressing time is 1min-15min.

[0045] Example 1

[0046] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0047] Step 1: Mix 50S and 50 (PEGDA) by mass. 30％ -ENB 70％ Weigh out the three monomers;

[0048] Step 2: Weigh 1 wt% of zinc diethyldithiocarbamate (Zn(DTC)2) from Step 1. Place S and Zn(DTC)2 into a round-bottom flask. When S is completely melted and forms an orange sulfur liquid, slowly add PEGDA and ENB dropwise to the system at 600 rpm for 2 hours. When the system turns brown and has a certain viscosity, pour the entire mixture into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer, which is named 50S-50 (PEGDA). 30％ -ENB 70％ After cooling to room temperature, the silicone mold was cured in a vacuum drying oven at 130℃ for 12 hours. Subsequently, mechanical property tests were conducted on samples prepared according to Type 1 specimens in GB-T 528-2009.

[0049] Example 2

[0050] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0051] Step 1: Mix 50S and 50 (PEGDA) by mass. 40％ -ENB 60％ Weigh out the three monomers;

[0052] Step 2: Weigh 1 wt% of zinc diethyldithiocarbamate (Zn(DTC)2) from Step 1. Place S and Zn(DTC)2 into a round-bottom flask. When S is completely melted and forms an orange sulfur liquid, slowly add PEGDA and ENB dropwise to the system at 600 rpm for 2 hours. When the system turns brown and has a certain viscosity, pour the entire mixture into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer, which is named 50S-50 (PEGDA). 40％ -ENB 60％ After cooling to room temperature, the silicone mold was cured in a vacuum drying oven at 130℃ for 12 hours. Subsequently, mechanical property tests were conducted on samples prepared according to Type 1 specimens in GB-T 528-2009.

[0053] Example 3

[0054] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0055] Step 1: Mix 50S and 50 (PEGDA) by mass. 50％ -ENB 50％ Weigh out the three monomers;

[0056] Step 2: Weigh 1 wt% of zinc diethyldithiocarbamate (Zn(DTC)2) from Step 1. Place S and Zn(DTC)2 into a round-bottom flask. When S is completely melted and forms an orange sulfur liquid, slowly add PEGDA and ENB dropwise to the system at 600 rpm for 2 hours. When the system turns brown and has a certain viscosity, pour the entire mixture into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer, which is named 50S-50 (PEGDA). 50％ -ENB 50％ After cooling to room temperature, the silicone mold was cured in a vacuum drying oven at 130℃ for 12 hours. Subsequently, mechanical property tests were conducted on samples prepared according to Type 1 specimens in GB-T 528-2009.

[0057] Example 4

[0058] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0059] Step 1: Mix 50S and 50 (PEGDA) by mass. 60％ -ENB 40％ Weigh out the three monomers;

[0060] Step 2: Weigh 1 wt% of zinc diethyldithiocarbamate (Zn(DTC)2) from Step 1. Place S and Zn(DTC)2 into a round-bottom flask. When S is completely melted and forms an orange sulfur liquid, slowly add PEGDA and ENB dropwise to the system at 600 rpm for 2 hours. When the system turns brownish and has a certain viscosity, pour the entire mixture into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer, which is named 50S-50 (PEGDA). 60％ -ENB 40％ After cooling to room temperature, the silicone mold was cured in a vacuum drying oven at 130℃ for 12 hours. Subsequently, mechanical property tests were conducted on samples prepared according to Type 1 specimens in GB-T 528-2009.

[0061] Example 5

[0062] The method for preparing the sulfur-rich polymer elastomer of the present invention is specifically implemented according to the following steps:

[0063] Step 1: Mix 50S and 50 (PEGDA) by mass. 70％ -ENB 30％ Weigh out the three monomers;

[0064] Step 2: Weigh 1 wt% of zinc diethyldithiocarbamate (Zn(DTC)2) from Step 1. Place S and Zn(DTC)2 into a round-bottom flask. When S is completely melted and forms an orange sulfur liquid, slowly add PEGDA and ENB dropwise to the system at 600 rpm. Let the reaction proceed for 2 hours to allow for complete reaction. When the system turns brownish and has a certain viscosity, pour the entire mixture into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer, which is named 50S-50 (PEGDA). 70％ -ENB 30％ After cooling to room temperature, the silicone mold was cured in a vacuum drying oven at 130℃ for 12 hours. Subsequently, mechanical property tests were conducted using specimens prepared according to Type 1 specimens in GB-T528-2009.

[0065] Test results:

[0066] The 50S-50 (PEGDA) prepared in the above five examples was analyzed. x -ENB y The polymer underwent 1The structure and properties of sulfur-rich polymer elastomers were analyzed by characterization using 1H NMR, FT-IR, XRD, TGA, DSC, EA, GPC, and mechanical properties.

[0067] like Figure 1 As shown, through 1 ¹H NMR revealed that as the reaction time increased, the C=C double bond peak of the olefin crosslinking agent gradually weakened, indicating that the S and unsaturated double bonds were successfully crosslinked. Furthermore, a large number of methylene peaks appeared in the range of 0.5–3 ppm, which is consistent with the characteristics of traditional desulfurization.

[0068] like Figure 2 and Figure 3 As shown, FT-IR analysis using polymers of different proportions revealed that at 3066 cm⁻¹... -1 and 1620cm -1 Both C=CH and C=C on the left and right sides disappeared, and were located at 460cm. -1 and 730cm -1 Characteristic peaks of SS and CS bonds were found on both sides, indicating that S, PEGDA, and ENB have undergone polymerization.

[0069] like Figure 4 As shown, the elastomers with different proportions were characterized by XRD. Compared with S, the characteristic crystallization peaks of S in the elastomers with different material ratios have all disappeared, indicating that S fully participates in the reaction and has an amorphous structure.

[0070] Elemental analysis was performed to determine the content of four elements (S, C, and H) in polymers with different proportions (Table 1). The elemental contents of different material ratios were consistent with the theoretical values, indicating that the elastomer has high atomic conversion efficiency and good atom economy, and can be used to prepare sulfur-rich polymer materials with different sulfur contents. Figure 5 As shown, the molecular weight of the polymer was determined by GPC. The polymer was dissolved in trichlorobenzene at high temperature. Its number-average molecular weight (Mn) was 33365 g / mol, its weight-average molecular weight (Mw) was 293699 g / mol, and its polydispersity index was 8.8.

[0071] X-ray photoelectron spectroscopy (XPS), such as Figure 6 , Figure 7 and Figure 8 (As shown) The chemical bond linkages in the polymer were analyzed, and O1s, C1s, S2p, and S2s bonds were detected. Figure 9 As shown, the glass transition temperature (Tg) of the polymer was analyzed by DSC curves. Since the sulfur content was fixed at 50% of the sum of the masses of the two olefin crosslinking agent monomers, its glass transition temperature remained relatively stable between 0 and -10℃. The Tg values ​​for each material were as follows: 50S-50 (PEGDA) 30％ -ENB 70％): -8.81℃

[0072] 50S-50 (PEGDA) 40％ -ENB 60％ ): -4.37℃, 50S-50 (PEGDA) 50％ -ENB 50％ ): -0.52℃, 50S-50 (PEGDA) 60％ -ENB 40％ ): 1.22℃, 50S-50 (PEGDA) 70％ -ENB 30％ ): -9.26℃.

[0073] like Figure 10 As shown, thermogravimetric analysis (TGA) of the above polymers revealed that 50S-50 (PEGDA) x -ENB y Before 200℃, its mass loss is almost zero, and there is only one obvious weight loss plateau, indicating that the copolymer has a relatively simple structure, the thermodynamic differences between the components are not significant, and the thermal stability is good.

[0074] Subsequently, mechanical property tests were conducted on elastomers with different proportions according to GB-T 528-2009. Figure 11 , 12 As shown. Stress-strain and Young's modulus tests were performed using a universal testing machine. Type 1 spline was selected, and the tensile speed was set to 500 mm / min.

[0075] When selecting 50S-50 (PEGDA) 50％ -ENB 50％ When the elastomer reaches a certain strength, the maximum stress is 1.201 MPa and the elongation at break is 196.209%.

[0076] When selecting 50S-50 (PEGDA) 40％ -ENB 60％ When the maximum stress is 6.192 MPa, the elongation at break is 132.874%, and the Young's modulus reaches 66.012 MPa.

[0077] Mechanical properties revealed that this sulfur-rich polymer elastomer retains stretchability while possessing a certain strength, with a maximum value of 196.209%.

[0078] Table 1 lists the sulfur-rich polymer elastomer 50S-50 (PEGDA) of the present invention. x -ENB y Elemental analysis.

[0079] Table 1 lists 50S-50 (PEGDA) x -ENB yElemental analysis

[0080] Sample number N(％) C(％) H(％) S(％) 1 0.181 45.619 5.022 24.221 2 0.096 48.745 4.656 33.808 3 0.076 48.487 4.850 32.507 4 0.000 46.388 4.934 31.475 5 0.000 44.061 4.737 32.593

[0081] The sulfur (S) used is industrial waste, and the selected olefin crosslinking agent is inexpensive and readily available, aligning with the concept of green development. Compared to traditional methods for preparing sulfur-rich polymers, this method yields a polymer with a weight-average molecular weight as high as 293,269 g / mol. This method is simple, safe, and efficient, requiring no raw material processing, and the sulfur used can be used as both a monomer and a solvent. The sulfur-rich polymer elastomer prepared by this invention possesses a two-dimensional crosslinked network structure that provides the material with strong stress and elongation at break. The sulfur-rich polymer elastomer prepared by this invention contains self-healing S-S weak bonds that can dynamically exchange at low temperatures, exhibiting a certain degree of re-additivity. It degrades under specific conditions, making it environmentally friendly. The elastomer prepared by this invention has an elongation at break approaching 200%, representing a significant improvement. The three components of the elastomer prepared by this invention have a mass ratio of 50S-50 (PEGDA). 40％ -ENB 60％ When the tensile strength is 6.192 MPa and the elongation at break is 132.874%, it maintains a certain strength while also being very flexible.

Claims

1. A sulfur-rich polymer elastomer, characterized in that, This includes using industrial waste S with monomers PEGDA and ENB to prepare sulfur-rich polymer elastomers with high strength and high toughness through desulfurization.

2. The sulfur-rich polymer elastomer according to claim 1, characterized in that, The raw materials, by mass percentage, comprise: 10wt%-90wt% polyethylene glycol diacrylate (PEGDA), 10wt%-90wt% ethylene-neobornene (ENB), and 30wt%-70wt% elemental sulfur. The resulting terpolymer is named "aS-b(PEGDA)". c -ENB d "a" and "b" represent the mass percentage of sulfur and the mass percentage of the crosslinking agent, respectively, while "c" and "d" represent the mass percentage of two different crosslinking agents.

3. A method for preparing sulfur-rich polymer elastomers, characterized in that, The specific steps are as follows: Step 1: Weigh out the following three monomers according to their mass ratio: polyethylene glycol diacrylate (PEGDA), ethylene-imide norbornene (ENB), and S. Step 2: Add sulfur (S) and catalyst to a round-bottom flask, rotate the magnetic stirrer evenly, and heat until the sulfur is fully melted. After the sulfur has fully melted for 10 minutes, slowly add polyethylene glycol diacrylate (PEGDA) and ethylene-methylnorbornene (ENB) dropwise to the round-bottom flask and stir to react fully. After the reaction is complete, pour the polymer into a silicone mold and allow it to cool naturally to room temperature to obtain the prepolymer. Place the prepolymer in a vacuum drying oven to cure. Step 3: The sample obtained in Step 2 is prepared by hot pressing followed by cold pressing using a flat vulcanizing machine to obtain S-PEGDA-ENB elastomer.

4. The method for preparing the sulfur-rich polymer elastomer according to claim 3, characterized in that, The structures of the two different organic comonomers PEGDA and ENB in ​​step 1 are as follows: Where n = 2.

5. The method for preparing the sulfur-rich polymer elastomer according to claim 4, characterized in that, In step 2, the amount of catalyst used is 1 wt% to 5 wt% of the total mass of the three comonomers.

6. The method for preparing the sulfur-rich polymer elastomer according to claim 4, characterized in that, The catalyst in step 2 is zinc diethyldithiocarbamate.

7. The method for preparing the sulfur-rich polymer elastomer according to claim 3, characterized in that, In step 2, the heating reaction temperature is 100-180℃, and the heating reaction time is 0.5-8h.

8. The method for preparing the sulfur-rich polymer elastomer according to claim 3, characterized in that, In step 2, the temperature of the vacuum drying oven is 100-150℃, and the curing time is 6-24h.

9. The method for preparing the sulfur-rich polymer elastomer according to claim 3, characterized in that, In step 3, the hot pressing temperature is 150℃-230℃, and the hot pressing time is 1min-15min.

10. The method for preparing the sulfur-rich polymer elastomer according to claim 3, characterized in that, The cold pressing time in step 3 is 1 min to 15 min.

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