Polyamide-polyether block copolymer elastomeric materials having branched architecture, and methods of making and using the same

Abstract

The application belongs to the technical field of copolymer elastomers, and particularly relates to a polyamide-polyether block copolymer elastomer material with a branched structure and a preparation method and application thereof; polyamide monomers, polyether monomers, at least three carboxyl functional branched monomers, linear dibasic acid, a catalyst and water are added into a reaction kettle, and then mixed to perform a melt polycondensation reaction; the melt polycondensation reaction process comprises the following steps: (1) a monomer ring-opening stage: the reaction temperature is 130-190 DEG C, the reaction time is 1-5 h, and the pressure is less than 0.5 MPa; (2) a pre-polycondensation stage: the reaction temperature is 190-240 DEG C, the reaction time is 1-5 h, and the pressure is less than 0.5 MPa; (3) a final polycondensation stage: the reaction temperature is 240-280 DEG C, the reaction time is 1-5 h, and the pressure is less than 200 Pa. The functional branched monomers are introduced to construct low-density chemical branched points, so that the material can significantly improve the mechanical properties and thermal stability while maintaining the thermoplastic processing performance.

Description

Technical Field

[0001] This invention belongs to the field of copolymer elastomer technology, specifically relating to a polyamide-polyether block copolymer elastomer material with a branched structure, its preparation method, and its application. Background Technology

[0002] In recent years, with the rapid development of society and industry, the demand and requirements for elastomers in various fields have become increasingly stringent. In the field of polyamide materials, polyamide elastomers have always been a hot topic of attention and research both domestically and internationally. However, existing polyamide elastomers suffer from poor mechanical properties during use. Summary of the Invention

[0003] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a branched polyamide-polyether block copolymer elastomer material, its preparation method, and its application that meet one or more of the aforementioned requirements.

[0004] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for preparing a polyamide-polyether block copolymer elastomer material with a branched structure, comprising adding polyamide monomer, polyether monomer, branched monomer with functional groups of at least three carboxyl groups, linear dicarboxylic acid, catalyst and water into a reaction vessel, mixing and then carrying out a melt polycondensation reaction; The melt polycondensation reaction process includes the following steps: (1) Monomer ring-opening stage: reaction temperature is 130-190°C, reaction time is 1-5h, and pressure is <0.5MPa; (2) Pre-polymerization stage: reaction temperature is 190-240°C, reaction time is 1-5h, pressure is <0.5MPa; (3) Final polycondensation stage: reaction temperature is 240-280°C, reaction time is 1-5h, and pressure is <200Pa.

[0005] As a preferred embodiment, the polyamide monomer is at least one selected from caprolactam, dodecylactam, and 11-aminoundecanoic acid.

[0006] As a preferred embodiment, the polyether monomer is at least one of polyether diamine, polyethylene glycol, polypropylene oxide, and polytetrahydrofuran.

[0007] As a preferred embodiment, the number-average molecular weight of the polyether monomer is 500 to 5000 g / mol.

[0008] As a preferred embodiment, the functionalized branched monomer with at least three carboxyl groups is at least one of pyromellitic acid, citric acid, and pyromellitic tetracarboxylic acid.

[0009] As a preferred embodiment, the mass ratio of the polyamide monomer, polyether monomer, functionalized branched monomer with at least three carboxyl groups, linear dicarboxylic acid, catalyst and water is (4-6):(4-6):(0.1-0.2):(0.01-0.05):(0.4-0.5).

[0010] As a preferred embodiment, the linear dicarboxylic acid is succinic acid, adipic acid, pimelic acid, octanoic acid, or azelaic acid; The catalyst is boric acid, sodium hypophosphite, or phosphoric acid.

[0011] The present invention also provides an elastomer material prepared by the preparation method described in any of the preceding embodiments, wherein the number-average molecular weight of the elastomer material is 10,000 to 30,000 g / mol, the molecular weight distribution index (PDI) is 2.5 to 3.5, and the degree of branching is 5.7 to 7.2%.

[0012] As a preferred embodiment, the elastomeric material has a tensile strength of 10–50 MPa and an elongation at break of 50–300%.

[0013] The present invention also provides applications of the elastomeric materials described above, for use in athletic shoe sole materials, cable protection sleeves, automotive seals, medical catheters, or 3D printing materials.

[0014] Compared with the prior art, the beneficial effects of this invention are: (1) This invention introduces functionalized branched monomers to construct low-density chemical branching points, thereby significantly improving the mechanical properties and thermal stability of the material while maintaining its thermoplastic processing properties. (2) The present invention prepares elastomers by one-step melt polycondensation and controls the ratio of hard segments to soft segments, so that the material has excellent elastic recovery performance, low compression set and good low temperature resistance. (3) This invention uses a portion of adipic acid to reduce the branching density and prevent the system from "gelling prematurely". Adipic acid is a linear dicarboxylic acid. Introducing adipic acid can dilute the trifunctional nodes in the system and transform part of the "three-dimensional network structure" into a "linear long chain structure". This greatly delays the gelation point, makes the reaction easier to control, and can obtain polymer chains with higher molecular weight and better toughness. (4) The preparation method of the present invention has the characteristics of simple process and suitable for industrial production. The resulting elastomer has broad application prospects in sports equipment, medical devices, wire and cable sheaths and automobile parts. Attached Figure Description

[0015] Figure 1The XRD pattern of the elastomer material in Example 1 of this invention is shown. Figure 2 The image shows the FTIR spectrum of the elastomer material in Example 1 of this invention. Figure 3 The stress-strain curves of the elastomeric materials in Examples 1, 2, and 3 of this invention are shown. Figure 4 This is a stress-strain curve diagram of the elastomeric material in Example 1 and Comparative Example 1 of the present invention; Figure 5 This is the NMR spectrum of the elastomer material of Example 1 of the present invention. Detailed Implementation

[0016] The following provides a detailed description of the branched polyamide-polyether block copolymer elastomer material of the present invention, its preparation method, and its application.

[0017] The present invention provides a method for preparing a branched polyamide-polyether block copolymer elastomer material, wherein polyamide monomer, polyether monomer, branched monomer with functional groups of at least three carboxyl groups, linear dicarboxylic acid, catalyst and water are added to a reaction vessel, and after mixing, a melt polycondensation reaction is carried out. Specifically, the melt polycondensation reaction process includes the following steps: (1) Monomer ring-opening stage: The reaction temperature is 130-190°C, the reaction time is 1-5h, and the pressure is <0.5MPa; the specific reaction temperature, reaction time and pressure can be determined according to the actual application requirements. (2) Pre-polymerization stage: The reaction temperature is 190-240°C, the reaction time is 1-5h, and the pressure is <0.5MPa; the specific reaction temperature, reaction time and pressure can be determined according to the actual application requirements. (3) Final polycondensation stage: The reaction temperature is 240-280°C, the reaction time is 1-5h, and the pressure is <200Pa; the specific reaction temperature, reaction time and pressure can be determined according to the actual application requirements.

[0018] The polyamide monomers mentioned above are at least one of caprolactam, dodecanoic acid, and 11-aminoundecanoic acid, and the specific monomers can be selected according to actual application requirements. As a preferred embodiment, the polyether monomer is at least one of polyether diamine, polyethylene glycol, polypropylene oxide, and polytetrahydrofuran, and can be selected according to actual application requirements; The number average molecular weight of the above polyether monomers is 500-5000 g / mol, which can be determined according to the actual application requirements; The functionalized branched monomers with at least three carboxyl groups mentioned above are at least one of pyromellitic acid, citric acid and pyromellitic tetracarboxylic acid, and can be selected according to actual application requirements; The mass ratio of polyamide monomer, polyether monomer, functionalized branched monomer with at least three carboxyl groups, linear dicarboxylic acid, catalyst and water is (4-6):(4-6):(0.1-0.2):(0.01-0.05):(0.4-0.5). The specific mass ratio can be determined according to the actual application requirements. The above-mentioned linear dicarboxylic acids, such as succinic acid, adipic acid, pimelic acid, octanoic acid, or azelaic acid, can be selected according to actual application requirements. The catalysts mentioned above are boric acid, sodium hypophosphite, or phosphoric acid, and the specific choice can be made according to the actual application requirements.

[0019] The elastomer material prepared by the above method has a number average molecular weight of 10,000–30,000 g / mol, a molecular weight distribution index (PDI) of 2.5–3.5, a degree of crosslinking of 5.7–7.2%, a tensile strength of 10–50 MPa, and an elongation at break of 50–300%.

[0020] Based on the above applications of elastomer materials, they can be used in sports shoe sole materials, cable protection sleeves, automotive seals, medical catheters, or 3D printing materials.

[0021] The following specific examples and comparative examples further illustrate the branched polyamide-polyether block copolymer elastomer material of the present invention, its preparation method, and its application.

[0022] Example 1: This embodiment uses a one-step melt polycondensation method to prepare the polyamide-polyether block copolymer elastomer material with a branched structure. 5g of caprolactam, 5g of polyether diamine (Mn = 2000g / mol), 50% hard segment, 0.24g of citric acid, 0.1825g of adipic acid, 0.015g of boric acid, and 0.5g of deionized water were weighed and added to the reactor. Air was replaced with N2, and the reactor was pressurized to 0.2MPa. The subsequent polymerization process was as follows: staged heating was used, first raising the temperature to 180℃ and holding for 2 hours, then raising it to 220℃ and holding for 2 hours, and finally raising it to 260℃ and holding for 4 hours, while maintaining a vacuum of -70kPa. After the reaction, the polymer was cooled and removed to obtain the elastomer material.

[0023] The elastomer material prepared in this embodiment has a number-average molecular weight (Mn) of 19 kg / mol, a molecular weight distribution index (PDI) of 2.8, and a branching degree of 5.7%.

[0024] Example 2: This embodiment uses a one-step melt polycondensation method to prepare the polyamide-polyether block copolymer elastomer material with a branched structure. 4g of dodecyl lactam, 6g of polypropylene oxide (PPG) (Mn = 2000g / mol), 0.21g of trimesic acid, 0.146g of adipic acid, 40% hard segment content, 0.01g of sodium hypophosphite, and 0.4g of deionized water were weighed and added to the reactor. Air was replaced with N2, and the reactor was pressurized to 0.2MPa. The subsequent polymerization process was as follows: staged heating was used, first raising the temperature to 190℃ and holding for 2 hours, then raising it to 230℃ and holding for 2 hours, and finally raising it to 270℃ and holding for 3 hours, while maintaining a vacuum of -80kPa. After the reaction, the polymer was cooled and removed to obtain the elastomer material.

[0025] The elastomer material prepared in this embodiment has a number-average molecular weight (Mn) of 21 kg / mol, a molecular weight distribution index (PDI) of 3.1, and a branching degree of 7.2%.

[0026] Example 3: This embodiment uses a one-step melt polycondensation method to prepare the product. 6g of 11-aminoundecanoic acid, 4g of polytetrahydrofuran (PTMG) (Mn 3000g / mol), with a hard segment ratio of 60%, 0.145g of pyromellitic acid, 0.146g of adipic acid, 0.02g of phosphoric acid, and 0.5g of deionized water were weighed and added to the reactor. Air was replaced with N2, and the reactor was pressurized to 0.2MPa. The subsequent polymerization process involved segmented heating: first, the temperature was raised to 200℃ and held for 2 hours; then, it was raised to 240℃ and held for 3 hours; finally, it was raised to 260℃ and held for 5 hours, while maintaining a vacuum of -82kPa. After the reaction, the polymer was cooled and removed to obtain a polyamide-polyether block copolymer elastomer material with a branched structure.

[0027] The elastomer material prepared in this embodiment has a number-average molecular weight (Mn) of 15 kg / mol, a molecular weight distribution index (PDI) of 3.3, and a branching degree of 7.1%.

[0028] Comparative Example 1: The elastomer material in this comparative example was prepared by a one-step melt polycondensation method, and its difference from that in Example 1 is as follows: No citric acid or adipic acid was added; all other steps were the same as in Example 1. The elastomer material prepared in this comparative example meets the requirements of a number-average molecular weight (Mn) of 17 kg / mol and a molecular weight distribution index (PDI) of 2.6.

[0029] Comparative Example 2: The elastomer material in this comparative example was prepared by a one-step melt polycondensation method, and its difference from that in Example 1 is as follows: Adipic acid was not added, and the mass of citric acid was increased to 0.48g; all other steps were the same as in Example 1. The elastomer material prepared in this comparative example did not contain adipic acid and had an excess of citric acid. The branching degree of this system was 7.5%, which resulted in cross-linking and ultimately yielded an insoluble and infusible product.

[0030] Comparative Example 3: The elastomer material in this comparative example was prepared by a one-step melt polycondensation method, and its difference from that in Example 1 is as follows: Without the addition of citric acid, the mass of adipic acid was increased to 0.365g; all other steps were the same as in Example 1. The elastomer material in this comparative example meets the requirements of a number-average molecular weight Mn of 13 kg / mol and a molecular weight distribution index (PDI) of 2.5.

[0031] The following tests characterize the elastomer materials of the above embodiments and comparative examples: like Figure 1 The figure shows the X-ray diffraction (XRD) pattern of the elastomer material prepared in Example 1 above. It can be seen from the figure that the two characteristic diffraction peaks at 20.34° and 24.38° belong to the α crystal form of PA6. Since the polyether soft segment is an amorphous phase, the corresponding characteristic diffraction peaks were not observed in the XRD pattern. The elastomer material has a microphase separation structure. like Figure 2 The figure shows the FTIR spectrum of the elastomer material prepared in Example 1 above. The presence of -NHCO- and -COC- can be seen from the figure, indicating that the elastomer material was successfully prepared. like Figure 3 As shown, the highest stress of the elastomer material in Example 1 can reach 48 MPa, while the strain can reach more than 250%. The mechanical properties of the elastomer material in Example 1 are significantly greater than those in Examples 2 and 3 because the preparation process uses a one-pot method. Example 1 involves an amidation reaction, while Examples 2 and 3 involve esterification reactions. The reaction rate of amidation is much greater than that of esterification. Therefore, Example 1 can complete the polymerization reaction more quickly, thus making its mechanical properties superior to those of Examples 2 and 3.

[0032] like Figure 4As shown, the branched polyamide elasticity of Example 1 exhibits superior mechanical properties compared to the unbranched polyamide elasticity of Comparative Example 1. This is because the branched structure introduces topological nodes in three-dimensional space, resulting in high molecular chain entanglement density and restricted macromolecular slippage. Furthermore, the branched structure possesses "recovery memory" capability, significantly improving the tensile strength and tear resistance of the material. The branched centers act like the "core" of an elastic pump; when the external force is removed, the three-dimensional branched network generates a strong rebound force, rapidly restoring the deformed soft segments to their original shape. This structure can be used in sports shoe sole materials, cable protection sleeves, automotive seals, medical catheters, 3D printing materials, etc. Therefore, the branched structure significantly reduces deformation and improves the elastic recovery rate. As shown in Table 1, the mechanical properties of Comparative Example 3, which lacks a branched structure, are inferior to those of Example 1. Because Comparative Example 2 produced insoluble and infusible crosslinking products, it was impossible to melt-prepare tensile specimens, thus preventing a comparison of tensile properties.

[0033] Table 1 Mechanical property test data ; like Figure 5 As shown, this illustrates the successful polymerization of the polyamide hard segment and the polyether soft segment in the elastomer material of Example 1.

[0034] Given that there are numerous embodiments of the present invention, and the raw materials and quantities involved can be selected within a limited range according to actual needs, and that the experimental data for each embodiment are extensive and numerous, it is not suitable to list and describe them one by one here. However, the content to be verified and the final conclusions obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here.

[0035] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a polyamide-polyether block copolymer elastomer material with a branched structure, characterized in that, Polyamide monomer, polyether monomer, functionalized branched monomer with at least three carboxyl groups, linear dicarboxylic acid, catalyst and water are added to a reactor, mixed and then subjected to melt polycondensation reaction. The melt polycondensation reaction process includes the following steps: (1) Monomer ring-opening stage: reaction temperature is 130-190°C, reaction time is 1-5h, and pressure is <0.5MPa; (2) Pre-polymerization stage: reaction temperature is 190-240°C, reaction time is 1-5h, pressure is <0.5MPa; (3) Final polycondensation stage: reaction temperature is 240-280°C, reaction time is 1-5h, and pressure is <200Pa.

2. The preparation method according to claim 1, characterized in that, The polyamide monomer is at least one of caprolactam, dodecylactam, and 11-aminoundecanoic acid.

3. The preparation method according to claim 1, characterized in that, The polyether monomer is at least one of polyether diamine, polyethylene glycol, polypropylene oxide, and polytetrahydrofuran.

4. The preparation method according to claim 3, characterized in that, The number-average molecular weight of the polyether monomer is 500–5000 g / mol.

5. The preparation method according to claim 1, characterized in that, The functionalized branched monomer with at least three carboxyl groups is at least one of pyromellitic acid, citric acid, and pyromellitic tetracarboxylic acid.

6. The preparation method according to claim 1, characterized in that, The mass ratio of the polyamide monomer, polyether monomer, branched monomer with at least three carboxyl groups, linear dicarboxylic acid, catalyst and water is (4-6):(4-6):(0.1-0.2):(0.01-0.05):(0.4-0.5).

7. The preparation method according to claim 1, characterized in that, The linear dicarboxylic acid is succinic acid, adipic acid, pimelic acid, octanoic acid, or azelaic acid; The catalyst is boric acid, sodium hypophosphite, or phosphoric acid.

8. The elastomer material prepared by the preparation method according to any one of claims 1-7, characterized in that, The elastomer material has a number-average molecular weight of 10,000–30,000 g / mol, a molecular weight distribution index (PDI) of 2.5–3.5, and a degree of branching of 5.7–7.2%.

9. The elastomer material according to claim 8, characterized in that, The elastomeric material has a tensile strength of 10–50 MPa and an elongation at break of 50–300%.

10. The application of the elastomeric material as described in claim 8 or 9, characterized in that, Used in athletic shoe sole materials, cable protection sleeves, automotive seals, medical catheters, or 3D printing materials.

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