A sodium allyl sulfonate hydroxyethyl methacrylate ionomer, its preparation method and application

Abstract

This invention belongs to the field of organic synthesis technology, specifically relating to an ionomer of sodium allyl sulfonate and hydroxyethyl methacrylate. This ionomer is obtained by reacting sodium allyl sulfonate monomer, hydroxyethyl methacrylate monomer, and an initiator. This ionomer can be added to PET as a nucleating agent to modify PET, increasing its melt crystallization temperature and accelerating its crystallization rate. Simultaneously, it effectively reduces PET degradation and improves its mechanical properties, providing a new avenue for the application of PET as an engineering plastic and expanding its applicability.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a sodium allyl sulfonate hydroxyethyl methacrylate ionomer, its preparation method, and its application. Background Technology

[0002] Polyethylene terephthalate (PET) is a thermoplastic polyester, available in non-engineering and engineering grades. PET possesses excellent physical and mechanical properties within a certain temperature range, such as high rigidity, high impact strength, and stability against many organic solvents and inorganic acids, making it widely applicable. However, the presence of benzene rings in the PET molecular backbone results in strong molecular chain rigidity. Furthermore, the highly polar ester groups linked to the benzene rings form a conjugated structure, further increasing the rigidity of the molecular chain and raising resistance to molecular motion. While PET possesses the flexible -CH2CH2- group, its short structure means the PET molecular chain remains predominantly rigid, leading to an increased crystallization temperature and decreased crystallization rate. This, in turn, makes PET difficult to process during injection molding, resulting in high mold temperatures and long production cycles, thus limiting its application in engineering plastics. Therefore, improving the crystallization rate has become one of the key technologies for the industrial modification of PET.

[0003] Adding nucleating agents during PET molding is an effective method to improve the crystallization properties of PET. Nucleating agents used in PET are generally classified into inorganic, organic, and polymeric types. Inorganic nucleating agents have poor dispersibility and ineffective nucleation. Organic nucleating agents are mostly hydroxy acid salts, whose nucleation mechanism is chemical nucleation, meaning they react with PET during processing to form nucleation sites for PET crystals, thus promoting PET crystallization, but causing PET chain breakage. Polymer nucleating agents are mostly ionomers; for example, Suryln resin developed by DuPont and AClyn ethylene acrylate ionomer developed by Honeywell are effective nucleating agents for PET. Currently, most effective nucleating agents for PET on the market are hydroxy acid salts, and other promising PET nucleating agents need to be developed. Summary of the Invention

[0004] The present invention aims to provide a sodium allyl sulfonate hydroxyethyl methacrylate ionomer, in order to provide a new PET nucleating agent and expand the range of PET nucleating agents available on the market.

[0005] To achieve the above objectives, the present invention provides: a sodium allyl sulfonate hydroxyethyl methacrylate ionomer, wherein the structural formula of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer is as follows:

[0006]

[0007] Where m and n are both natural numbers, and the value of m / n ranges from 0.1 to 9.

[0008] This invention also provides a method for preparing sodium allyl sulfonate hydroxyethyl methacrylate ionomer, comprising the following steps:

[0009] S1. Sodium allyl sulfonate monomer, hydroxyethyl methacrylate monomer and the first solvent are mixed evenly to obtain a mixture. The initiator is dissolved in the second solvent and then added dropwise to the mixture. The mixture is heated to 70-80°C and reacted for 3-6 hours.

[0010] S2. After the reaction is complete, the crude product is obtained by rotary drying. The crude product is dissolved and placed in a precipitant to precipitate. After purification and drying, the sodium allyl sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0011] Optionally, in step S1, the molar ratio between sodium allyl sulfonate monomer and hydroxyethyl methacrylate monomer is 1:0.1 to 9, and the molar ratio of the sum of the moles of sodium allyl sulfonate monomer and hydroxyethyl methacrylate monomer to the molar ratio of the initiator is 100:1 to 0.1.

[0012] Optionally, in step S1, the first solvent is an aqueous ethanol solution, wherein the volume ratio of anhydrous ethanol to water in the aqueous ethanol solution is 1 to 10:3; the second solvent is deionized water.

[0013] Optionally, in step S1, the initiator is a sulfate-bisulfite.

[0014] Optionally, in step S2, the precipitant is anhydrous ethanol.

[0015] Optionally, in step S1, the initiator is dissolved in the second solvent and then added dropwise to the mixture at a rate of 4 to 8 seconds per drop.

[0016] The above-mentioned sodium allyl sulfonate hydroxyethyl methacrylate ionomer can be used as a nucleating agent in the modification of polyethylene terephthalate (PET). In application, the sodium allyl sulfonate hydroxyethyl methacrylate ionomer is mixed evenly with PET, melt-blended at 250–270°C for 4–7 minutes, and then extruded and granulated to obtain the modified PET product. The mass ratio of sodium allyl sulfonate hydroxyethyl methacrylate ionomer to PET is 1:100–1000.

[0017] The working principle and beneficial effects of this invention are as follows: Firstly, the introduction of sodium sulfonate groups into the ionomer can generate ion clusters in the PET melt, providing nuclei and interfaces for crystallization, accelerating the ordered arrangement of molecular chains (heterogeneous nucleation mechanism). Furthermore, the flexible molecular chains of the ionomer can accelerate the movement of PET molecular chains, indirectly increasing the crystallization rate of PET. Secondly, the presence of metal salts allows the ionomer to maintain a stable structure above the melting point of PET, thereby providing more interfaces for PET crystallization. Therefore, the ionomer in this invention can increase the melting and crystallization temperature of PET and accelerate the crystallization rate.

[0018] Furthermore, unlike hydroxyl acid salt nucleating agents, sulfonate-based nucleating agents do not cause PET degradation and a significant decrease in molecular weight, which in turn leads to a reduction in PET's mechanical properties. Additionally, hydroxyethyl methacrylate (HEMA) monomer has a similar molecular structure to PET, and the presence of transesterification enhances compatibility. Therefore, the introduction of HEMA monomer can improve the compatibility between the nucleating agent and PET, resulting in uniform dispersion of the nucleating agent in PET and a significant modification effect.

[0019] Compared with sodium styrene sulfonate ionomers, the sodium allyl sulfonate ionomers in this scheme have more flexible chains and stronger crystallization effects. On this basis, this scheme can also effectively reduce the degradation of PET and improve the mechanical properties of PET, providing a new way for PET to be used as an engineering plastic and expanding the application range of PET.

[0020] In addition, the preparation method of the present invention uses solution polymerization, which allows all monomers to be added at once and the initiator to be added dropwise, making the preparation simple and precise. Attached Figure Description

[0021] Figure 1 The above is the 1H NMR spectrum of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer obtained in Example 2 of this invention;

[0022] Figure 2 The above is the 1H NMR spectrum of the sodium styrene sulfonate hydroxyethyl methacrylate ionomer obtained in the comparative example of this invention.

[0023] Figure 3 Thermogravimetric analysis curves of PET and PET / SAS-HEMA;

[0024] Figure 4 Crystallization curves of PET and PET / SAS-HEMA during the cooling process at 20℃ / min;

[0025] Figure 5 Crystallization curves of PET and PET / SAS-HEMA during the cooling process at 10℃ / min;

[0026] Figure 6 The stress-strain curves are for PET, PET / SAS-HEMA, and PET / SSS-HEMA. Detailed Implementation

[0027] The following detailed description illustrates the specific implementation method:

[0028] Example 1

[0029] This embodiment provides an allyl sulfonate sodium hydroxyethyl methacrylate ionomer, and the preparation method of the allyl sulfonate sodium hydroxyethyl methacrylate ionomer is as follows:

[0030] (1) 2.70 g of sodium allyl sulfonate (SAS) monomer, 0.25 mL of hydroxyethyl methacrylate (HEMA) monomer, and an aqueous ethanol solution were mixed evenly to obtain a mixture; wherein, the aqueous ethanol solution was prepared by mixing 18.75 mL of deionized water and 6.25 mL of anhydrous ethanol. 0.048 g of ammonium persulfate, 0.016 g of sodium bisulfite, and 15 mL of deionized water were mixed evenly and placed in a constant pressure dropping funnel. After the reaction system was heated to 80 °C, it was added dropwise to the mixture at a rate of 5 s / drop. The reaction was allowed to proceed for 6 h (the starting point of the reaction time was the moment when the initiator began to be added; other examples were the same as the comparative example).

[0031] (2) After the reaction is complete, the deionized water and solvent (ethanol) in the reaction system are evaporated to dryness to obtain crude product. The crude product is dissolved in deionized water and then placed in anhydrous ethanol to precipitate. After dialysis and vacuum drying, sodium allyl sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0032] Example 2

[0033] This embodiment provides an allyl sulfonate sodium hydroxyethyl methacrylate ionomer, and the preparation method of the allyl sulfonate sodium hydroxyethyl methacrylate ionomer is as follows:

[0034] (1) 2.42 g of sodium allyl sulfonate (SAS) monomer, 0.51 mL of hydroxyethyl methacrylate (HEMA) monomer, and an aqueous ethanol solution were mixed evenly to obtain a mixture; wherein the aqueous ethanol solution was prepared by mixing 18.75 mL of deionized water and 6.25 mL of anhydrous ethanol. 0.048 g of ammonium persulfate, 0.016 g of sodium bisulfite, and 15 mL of deionized water were mixed evenly and placed in a constant pressure dropping funnel. After the reaction system was heated to 80 °C, it was added dropwise to the mixture at a rate of 5 s / drop and the reaction was allowed to proceed for 6 h.

[0035] (2) After the reaction is complete, the deionized water and solvent (ethanol) in the reaction system are evaporated to dryness to obtain crude product. The crude product is dissolved in deionized water and then placed in anhydrous ethanol to precipitate. After dialysis and vacuum drying, sodium allyl sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0036] Example 3

[0037] This embodiment provides an allyl sulfonate sodium hydroxyethyl methacrylate ionomer, and the preparation method of the allyl sulfonate sodium hydroxyethyl methacrylate ionomer is as follows:

[0038] (1) 2.12 g of sodium allyl sulfonate (SAS) monomer, 0.76 mL of hydroxyethyl methacrylate (HEMA) monomer, and an aqueous ethanol solution were mixed evenly to obtain a mixture; wherein the aqueous ethanol solution was prepared by mixing 18.75 mL of deionized water and 6.25 mL of anhydrous ethanol. 0.048 g of ammonium persulfate, 0.016 g of sodium bisulfite, and 15 mL of deionized water were mixed evenly and placed in a constant pressure dropping funnel. After the reaction system was heated to 80 °C, it was added dropwise to the mixture at a rate of 5 s / drop and the reaction was allowed to proceed for 6 h.

[0039] (2) After the reaction is complete, the deionized water and solvent (ethanol) in the reaction system are evaporated to dryness to obtain crude product. The crude product is dissolved in deionized water and then placed in anhydrous ethanol to precipitate. After dialysis and vacuum drying, sodium allyl sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0040] Example 4

[0041] This embodiment provides an allyl sulfonate sodium hydroxyethyl methacrylate ionomer, and the preparation method of the allyl sulfonate sodium hydroxyethyl methacrylate ionomer is as follows:

[0042] (1) 1.82 g of sodium allyl sulfonate (SAS) monomer, 1.02 mL of hydroxyethyl methacrylate (HEMA) monomer, and an aqueous ethanol solution were mixed evenly to obtain a mixture; wherein the aqueous ethanol solution was prepared by mixing 18.75 mL of deionized water and 6.25 mL of anhydrous ethanol. 0.048 g of ammonium persulfate, 0.016 g of sodium bisulfite, and 15 mL of deionized water were mixed evenly and placed in a constant pressure dropping funnel. After the reaction system was heated to 80 °C, it was added dropwise to the mixture at a rate of 5 s / drop, and the reaction was allowed to proceed for 6 h.

[0043] (2) After the reaction is complete, the deionized water and solvent (ethanol) in the reaction system are evaporated to dryness to obtain crude product. The crude product is dissolved in deionized water and then placed in anhydrous ethanol to precipitate. After dialysis and vacuum drying, sodium allyl sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0044] Comparative Example

[0045] This comparative example provides an ionomer of sodium p-styrene sulfonate and hydroxyethyl methacrylate, and the preparation method of this ionomer is as follows:

[0046] (1) 1.73 g of sodium styrene sulfonate (SSS) monomer, 1.53 mL of hydroxyethyl methacrylate (HEMA) monomer, and an aqueous ethanol solution were mixed evenly to obtain a mixture; wherein the aqueous ethanol solution was prepared by mixing 18.75 mL of deionized water and 6.25 mL of anhydrous ethanol. 0.048 g of ammonium persulfate, 0.016 g of sodium bisulfite, and 15 mL of deionized water were mixed evenly and placed in a constant pressure dropping funnel. After the reaction system was heated to 70 °C, it was added dropwise to the mixture at a rate of 5 s / drop, and the reaction was allowed to proceed for 3 h.

[0047] (2) After the reaction is completed, the deionized water and solvent (ethanol) in the reaction system are evaporated to dryness to obtain crude product. The crude product is dissolved in deionized water and then placed in anhydrous ethanol to precipitate. After dialysis and vacuum drying, sodium styrene sulfonate hydroxyethyl methacrylate ionomer product is obtained.

[0048] Figure 1 The image shows the 1H NMR spectrum of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer obtained in Example 2. Figure 1 It can be determined from the data that Example 2 synthesized a random copolymer of sodium allyl sulfonate and hydroxyethyl methacrylate ionomer.

[0049] Figure 2 The above is the 1H NMR spectrum of the sodium styrene sulfonate hydroxyethyl methacrylate ionomer obtained in the comparative example. Figure 2 It can be determined that the comparative synthesis is a random copolymer of sodium styrene sulfonate hydroxyethyl methacrylate ionomer.

[0050] Application Example 1

[0051] The sodium allyl sulfonate hydroxyethyl methacrylate ionomer obtained in the examples was used as a nucleating agent and melt-blended with polyethylene terephthalate to prepare a polyethylene terephthalate / sodium allyl sulfonate hydroxyethyl methacrylate ionomer composite, which yielded the modified polyethylene terephthalate. The nucleating agent and polyethylene terephthalate were melt-blended at 250–270°C for 4–7 min, and the mass ratio of the nucleating agent to polyethylene terephthalate was 1:100–1000.

[0052] Specifically, the nucleating agent (sodium allyl sulfonate hydroxyethyl methacrylate ionomer obtained in Example 2) was mixed with PET at a mass ratio of 1:100. Then, the mixture was melt-blended at 250-270°C and 60 rpm for 5 min, and extruded and granulated to obtain the modified polyethylene terephthalate, denoted as PET / SAS-HEMA.

[0053] Application Example 2

[0054] The sodium styrene sulfonate hydroxyethyl methacrylate ionomer obtained in the comparative example was used as a nucleating agent and mixed with PET at a mass ratio of 1:100. Then, it was melt-blended at 250-270℃ and 60rpm for 5 minutes, and extruded and granulated to obtain the modified polyethylene terephthalate, denoted as PET / SSS-HEMA.

[0055] In addition, pure polyethylene terephthalate was also processed under the same conditions as a reference sample, namely, pure polyethylene terephthalate was melt-blended at 250-270°C and 60 rpm for 5 min and then extruded and granulated.

[0056] The thermal decomposition temperature of the nucleating agent needs to be above the processing temperature of PET. Therefore, the thermal stability of PET / SAS-HEMA can be characterized using thermogravimetric analysis (TGA), and the results are as follows: Figure 3 As shown. (Through) Figure 3 It can be seen that the TGA curves of pure PET and PET / SAS-HEMA are almost identical, indicating that the nucleating agent can remain solid without degradation below 400℃ and can also play a role at the processing temperature of PET, thus providing nucleation sites for pure PET.

[0057] PET and PET / SAS-HEMA were characterized using differential scanning calorimetry (DSC), and the results are as follows: Figure 4 and Figure 5 As shown. From Figure 4 and Figure 5 Analysis revealed that the crystallization temperature of PET / SAS-HEMA was 189.3℃, while that of pure PET was 168.0℃. This indicates that the initial crystallization temperature and melting crystallization temperature of PET / SAS-HEMA were significantly higher compared to the PET sample. Furthermore, the half-peak width of the melting crystallization peak narrowed. These data all demonstrate that sodium allyl sulfonate hydroxyethyl methacrylate ionomer, acting as a nucleating agent, effectively accelerated the crystallization rate of PET.

[0058] The viscosities of pure PET and PET / SAS-HEMA were tested using an Ubbelohde viscometer, and the results are shown in Table 1. The mechanical properties of the dumbbell-shaped samples were tested using a universal testing machine. The stress-strain curves for pure PET, PET / SAS-HEMA, and PET / SSS-HEMA are shown below. Figure 6 As shown in Table 2, the specific data is as follows.

[0059] Table 1 Viscosity Test Results

[0060] Serial Number sample Intrinsic viscosity (dL / g) Viscosity-average molecular weight (g / mol) 1 PET 1.103 <![CDATA[3.4×10 4 ]]> 2 PET / SAS-HEMA 1.079 <![CDATA[3.3×10 4 ]]>

[0061] Table 2. Results of Mechanical Performance Tests

[0062]

[0063]

[0064] Table 1 shows that the intrinsic viscosity of PET / SAS-HEMA is 1.079 dL / g, while the intrinsic viscosity of pure PET is 1.103 dL / g. This indicates that the addition of sodium allyl sulfonate hydroxyethyl methacrylate ionomer as a nucleating agent to PET does not significantly reduce the intrinsic viscosity of PET, nor does it cause significant degradation of PET. Table 2 and... Figure 6 It is evident that the elongation at break and tensile strength of PET / SAS-HEMA are significantly higher than those of PET and PET / SSS-HEMA. Specifically, the elongation at break of PET / SAS-HEMA is 33.8% higher than that of PET / SSS-HEMA, and the tensile strength of PET / SAS-HEMA is 14.1% higher than that of PET / SSS-HEMA. Moreover, the elongation at break of PET / SSS-HEMA is lower than that of PET. Therefore, the ionomer of sodium allyl sulfonate hydroxyethyl methacrylate significantly reduces the number of large and brittle spherulites in PET and increases its crystallinity, leading to an increase in Young's modulus, elongation at break, and tensile strength of PET / SAS-HEMA. This improves both resistance to deformation and fracture, transforming the common brittle fracture behavior into ductile fracture behavior.

[0065] In summary, the sodium allyl sulfonate hydroxyethyl methacrylate ionomer of the present invention, after modifying PET, can not only increase the crystallization temperature and accelerate the crystallization rate of PET, but also effectively reduce the degradation of PET and improve the mechanical properties of PET, providing a new way for PET to be used as an engineering plastic and expanding the application range of PET.

[0066] The above are merely embodiments of the present invention. The invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can improve and implement this solution based on the guidance provided in this application and their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness or practicality of the invention. The scope of protection claimed in this application should be determined by the content of its claims. The specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A sodium allyl sulfonate hydroxyethyl methacrylate ionomer characterized by: The structure of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer is as follows: wherein m and n are both natural numbers, and the value range of m / n is 0.1-9.

2. A process for the preparation of sodium allylsulfonate methacrylate hydroxyethyl acrylate ionomer as claimed in claim 1, characterized by: The method comprises the following steps: S1, uniformly mixing sodium allyl sulfonate monomers, hydroxyethyl methacrylate monomers and a first solvent to obtain a mixed solution, dissolving an initiator in a second solvent, and then adding the initiator dropwise into the mixed solution, heating to 70-80°C, and reacting for 3-6 hours; S2, after the reaction is completed, spin-drying to obtain a crude product, dissolving the crude product, and then precipitating in a precipitant, and then purifying and drying to obtain a sodium allyl sulfonate hydroxyethyl methacrylate ionomer product.

3. The method of claim 2, wherein: In step S1, the molar ratio of the sodium allyl sulfonate monomers to the hydroxyethyl methacrylate monomers is 1:0.1-9, and the molar ratio of the sum of the sodium allyl sulfonate monomers and the hydroxyethyl methacrylate monomers to the initiator is 100:1-0.

1.

4. The method of claim 2, wherein: In step S1, the first solvent is an ethanol aqueous solution, and in the ethanol aqueous solution, the volume ratio of anhydrous ethanol to water is 1-10:3; the second solvent is deionized water.

5. The method of claim 2, wherein: In step S1, the initiator is a sulfate-hydrogen sulfite.

6. The method of claim 2, wherein: In step S2, the precipitant is anhydrous ethanol.

7. The method of claim 2, wherein: In step S1, after the initiator is dissolved in the second solvent, the initiator is added dropwise into the mixed solution at a drop rate of 4-8 s / drop.

8. Application of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer of claim 1 as a nucleating agent in modification of polyethylene terephthalate.

9. Use according to claim 8, characterized in that: The sodium allyl sulfonate hydroxyethyl methacrylate ionomer of claim 1 is uniformly mixed with polyethylene terephthalate, melt-blended at 250-270°C for 4-7 minutes, extruded and granulated to obtain a modified polyethylene terephthalate product.

10. Use according to claim 9, characterized in that: The mass ratio of the sodium allyl sulfonate hydroxyethyl methacrylate ionomer to the polyethylene terephthalate is 1:100-1000.

Images