Polyamide elastomer and foaming material thereof

Abstract

The invention relates to a polyamide elastomer and a foam material thereof, the polyamide elastomer comprises a hard segment and a soft segment, the hard segment comprises a polyamide block, and the soft segment comprises a polyether block and / or a polyester block; wherein the molar ratio of the hard segment to the soft segment is (2-3): (2-3); the number-average molecular weight of the hard segment is 1000-3000, and the mass ratio of the hard segment to the soft segment is (1-3): 1; the polyamide elastomer is prepared by reacting a hard-segment raw material with a soft-segment raw material, and the hydroxyl value of the soft-segment raw material is 30-600mgKOH / g. The polyamide elastomer disclosed by the embodiment of the invention has the characteristics of narrow molecular weight distribution, high melt mass flow rate and excellent mechanical property and wear resistance; and when being used for preparing a foaming material, the composite material can improve the stability in the foaming processing process and the performance of the foaming material, such as the closed-cell rate.

Description

Technical Field

[0001] The invention relates to a polyamide elastomer, in particular to a polyamide elastomer capable of improving the performance of foaming materials. Background Art

[0002] Thermoplastic polyamide elastomer (TPAE) is a block copolymer composed of hard segment polyamide and soft segment polyester or polyether. It has good flexibility, excellent mechanical properties and high elastic recovery rate. It is widely used in foaming shoes, sports, packaging and automobiles. However, the traditional raw material precursors of TPAE mainly come from fossil materials, which greatly limits its sustainability. The polyamide hard segment of existing bio-based TPAE is usually made from bio-based raw materials, while the soft segment polyester or polyether is a traditional non-bio-based material. Based on the requirements of the dual carbon strategy and the great demand for sustainable development, it is of great significance to develop green and environmentally friendly all-bio-based TPAE materials.

[0003] In addition, compared with other elastomer foaming materials, TPAE foaming materials are widely used in high-end foaming fields due to their ultra-light and ultra-elastic advantages. However, due to its simple linear polymer chain structure, problems such as low melt viscosity, cell aggregation or rupture often occur during the foaming process, resulting in low closed-cell rate, poor compression recovery and mechanical properties of the final foamed products. Summary of the invention

[0004] In order to overcome at least one defect of the above-mentioned prior art, in the first aspect, an embodiment of the present invention provides a polyamide elastomer, comprising a hard segment and a soft segment, wherein the hard segment comprises a polyamide block, and the soft segment comprises a polyether block and / or a polyester block; wherein the molar ratio of the hard segment to the soft segment is (2-3):(2-3); the number average molecular weight of the hard segment is 1000-3000, and the mass ratio of the hard segment to the soft segment is (1-3):1; the polyamide elastomer is obtained by reacting a hard segment raw material and a soft segment raw material, and the hydroxyl value of the soft segment raw material is 30-600 mgKOH / g.

[0005] In a second aspect, an embodiment of the present invention provides a foaming material composition, comprising the above-mentioned polyamide elastomer and additives.

[0006] In a third aspect, an embodiment of the present invention provides a polyamide elastomer foam material, which is obtained by foaming the above-mentioned foam material composition.

[0007] In a fourth aspect, an embodiment of the present invention provides the use of the above-mentioned foaming material in sports shoes and clothing, cushioning materials, packaging materials, seat cushions, mattresses, automobiles, aerospace or construction.

[0008] The polyamide elastomer of one embodiment of the present invention has the characteristics of narrow molecular weight distribution, high melt mass flow rate, excellent mechanical properties and wear resistance; and when used to prepare a foaming material, it can improve the stability during the foaming process and the closed cell rate and other properties of the foaming material. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings are only used to illustrate specific embodiments and are not to be considered as limiting the present invention.

[0010] Figure 1 This is a SEM image of the all-biobased polyamide elastomer foam material of Example 1 of the present invention;

[0011] Figure 2 This is a SEM image of the all-biobased polyamide elastomer foam material of Example 2 of the present invention;

[0012] Figure 3 This is a SEM image of the all-biobased polyamide elastomer foam material of Example 3 of the present invention;

[0013] Figure 4 This is a SEM image of the all-biobased polyamide elastomer foam material of Example 4 of the present invention;

[0014] Figure 5 This is a SEM image of the all-biobased polyamide elastomer foam material of Comparative Example 1;

[0015] Figure 6 This is a SEM image of the all-biobased polyamide elastomer foam material of Comparative Example 2;

[0016] Figure 7 This is a SEM image of the polyamide elastomer foam material of Comparative Example 3;

[0017] Figure 8 This is the SEM image of the polyamide elastomer foam material of Comparative Example 4. DETAILED DESCRIPTION

[0018] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions therein are essentially used as illustrations rather than to limit the present invention.

[0019] One embodiment of the present invention provides a polyamide elastomer, including a hard segment and a soft segment, wherein the hard segment includes a polyamide block, and the soft segment includes a polyether block and / or a polyester block; wherein the molar ratio of the hard segment to the soft segment is (2-3):(2-3); the number average molecular weight of the hard segment is 1000-3000, and the mass ratio of the hard segment to the soft segment is (1-3):1; the polyamide elastomer is prepared by reacting a hard segment raw material and a soft segment raw material, and the hydroxyl value of the soft segment raw material is 30-600 mgKOH / g.

[0020] In one embodiment, the hard segment raw material includes polyamide, and may further be carboxyl-terminated polyamide; the soft segment raw material includes hydroxyl-terminated polyester polyol and / or polyether polyol.

[0021] In one embodiment, the polyamide elastomer is a block polymer having alternating hard segments and soft segments.

[0022] In one embodiment, the molar ratio of the hard segment to the soft segment (or the molar ratio of the hard segment raw material to the soft segment raw material) can be (2-3):(2-3), and can further be (0.9-1.1):(0.9-1.1), for example, 2:3, 0.9:1.1, 1:1, 1.1:0.9, 1.5:2, 2:1.5, 3:2.

[0023] In one embodiment, the number average molecular weight of the hard segment or the number average molecular weight of the hard segment raw material may be 1000-3000, and further may be 1000-2000, for example, 1200, 1500, 1600, 1800, 2000, 2200, 2500 or 2800.

[0024] In one embodiment, the molecular weight of the soft segment or the number average molecular weight of the soft segment raw material can be 300 to 3000, for example, 350, 800, 1300, 1800, 2300, 2800.

[0025] In one embodiment, the mass ratio of the hard segment to the soft segment (or the mass ratio of the hard segment raw material to the soft segment raw material) can be (1-3):1, for example, 1:1, 1.5:1, 2:1, 2.5:1.

[0026] In one embodiment, the hydroxyl value of the soft segment raw material can be 30 to 600 mgKOH / g, such as 40 mgKOH / g, 75 mgKOH / g, 78 mgKOH / g, 80 mgKOH / g, 90 mgKOH / g, 100 mgKOH / g, 120 mgKOH / g, 123 mgKOH / g, 125 mgKOH / g, 140 mgKOH / g, 141 mgKOH / g, 145 mgKOH / g, 165 mgKOH / g, 167 mgKOH / g, 170 mgKOH / g, 180 mgKOH / g, 200 mgKOH / g, 300 mgKOH / g, 400 mgKOH / g, 500 mgKOH / g. Further, the hydroxyl value of the soft segment raw material can be 70 to 170 mgKOH / g.

[0027] In one embodiment, the weight average molecular weight of the polyamide elastomer is 65000-120000, and can further be 75000-101000, such as 70000, 75000, 80000, 82000, 85000, 90000, 95000, 100000, 101000 or 110000. The weight average molecular weight and molecular weight distribution of the polyamide elastomer are measured by GPC.

[0028] In one embodiment, the molecular weight distribution of the polyamide elastomer may be 0.7 to 3.5, and further may be 1.5 to 2.1, for example, 1.0, 1.2, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.5, 3.0 or 3.2.

[0029] In one embodiment, the melt mass flow rate of the polyamide elastomer at 210° C. and 2.5 kg is 10 to 90 g / 10 min, and can further be 20 to 75 g / 10 min, such as 20 g / 10 min, 30 g / 10 min, 38 g / 10 min, 40 g / 10 min, 50 g / 10 min, 60 g / 10 min, 70 g / 10 min, and 75 g / 10 min. The melt mass flow rate of the polyamide elastomer is measured according to GB / T3682-2000.

[0030] In one embodiment, the tensile modulus of the polyamide elastomer may be 110-160 MPa, such as 110 MPa, 115 MPa, 120 MPa, 123 MPa, 125 MPa, 130 MPa, 140 MPa, 142 MPa, 145 MPa, 150 MPa, 156 MPa, wherein the tensile modulus of the polyamide elastomer is measured according to ISO 527-1.

[0031] In one embodiment, the polymeric raw material polyamide is a bio-based polyamide.

[0032] In one embodiment, the polymeric starting polyester polyol is a bio-based polyester polyol.

[0033] In one embodiment, the polymerization base polyether polyol is a bio-based polyether polyol.

[0034] In one embodiment, the polyamide elastomer is a fully bio-based polyamide elastomer, that is, its polymer raw materials are all bio-based substances.

[0035] In one embodiment, the hard segment raw material includes one or more of polyamide 13, polyamide 12, polyamide 11, polyamide 10, polyamide 10T, polyamide 1010, polyamide 510, polyamide 610, polyamide 1012, polyamide 410, polyamide 1012, polyamide 46, and polyamide 56.

[0036] In one embodiment, the soft segment raw material includes one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polytrimethylene ether glycol, poly(1,3-propylene succinate) glycol, poly(butylene succinate), poly(1,3-propylene sebacate), and poly(butylene sebacate).

[0037] One embodiment of the present invention provides a method for preparing the above-mentioned polyamide elastomer, comprising melt-polymerizing a hard segment raw material and a soft segment raw material under the action of a catalyst, preferably synthesizing them by a dibasic acid method.

[0038] In one embodiment, the method for preparing a polyamide elastomer comprises the following steps:

[0039] S1: reacting polyamide with dibasic acid to obtain a carboxyl-terminated hard segment raw material; and

[0040] S2: reacting the hard segment raw material with the soft segment raw material under the action of a catalyst to obtain a polyamide elastomer.

[0041] In one embodiment, the method for preparing a polyamide elastomer comprises the following steps:

[0042] S1: In a nitrogen atmosphere, polyamide, dibasic acid and pure water are mixed and added into a high-pressure reactor, the temperature is raised to 150-220°C (e.g., 180°C, 190°C, 200°C, 210°C), the pressure is raised to 1.5-3.5MPa (e.g., 1.8MPa, 2MPa, 3MPa), the pressure is released to normal pressure after reacting for 2-6h (e.g., 3.5h, 4h, 5h), the absolute pressure is evacuated to 50-150Pa (e.g., 80Pa, 90Pa, 100Pa, 120Pa), the temperature is raised to 230-300°C (e.g., 240°C, 250°C, 260°C, 270°C), the reaction is carried out for 1-4h (e.g., 1.5h, 2h, 2.5h, 3h), and a carboxyl-terminated polyamide (hard segment raw material) is obtained;

[0043] S2: Add the soft segment raw material and the catalyst to the reaction system of step S1 under a nitrogen atmosphere, evacuate to an absolute pressure of 50-200 Pa (e.g., 70 Pa, 80 Pa, 100 Pa, 150 Pa), and carry out esterification reaction at 200-270° C. (e.g., 230° C., 240° C., 250° C., 260° C.) for 2-6 h (e.g., 3 h, 4 h, 5 h) to obtain a fully bio-based polyamide elastomer.

[0044] In one embodiment, the dibasic acid in step S1 can be selected from one or more of aliphatic straight-chain dibasic acids and aromatic dibasic acids. The aliphatic straight-chain dibasic acid can include a straight-chain dibasic acid containing 6 to 12 carbon atoms, such as adipic acid, suberic acid, sebacic acid, and dodecanedioic acid; the aromatic dibasic acid can include terephthalic acid, isophthalic acid, and phthalic acid.

[0045] In one embodiment, the molar ratio of the dibasic acid to the hard segment raw material is 1 to 1.2:1, such as 1.05:1 or 1.1:1.

[0046] In one embodiment, the catalyst of step S2 is one or more of zirconium, antimony, titanium and germanium catalysts, such as tetraethyl germanium, tetrabutyl titanate, zirconium n-propoxide, zirconium n-butoxide, and ethylene glycol antimony; the amount of the catalyst added accounts for 0.05-5% of the total mass of the hard segment raw material and the soft segment raw material.

[0047] In one embodiment, a reaction aid is also added in step S2. The reaction aid can be selected from an antioxidant and / or an ultraviolet absorber, for example, one or more of commercially available antioxidants 1076, antioxidant 626, antioxidant 1010, antioxidant 168, antioxidant 1098, ultraviolet absorber UV312, ultraviolet absorber UV326, and ultraviolet absorber UV531 can be used.

[0048] One embodiment of the present invention provides a foaming material composition, comprising the above-mentioned polyamide elastomer and additives.

[0049] In one embodiment, the additive comprises a nucleating agent.

[0050] In one embodiment, the foaming material composition includes 80 to 100 parts by mass (e.g., 82 parts by mass, 85 parts by mass, 88 parts by mass, 90 parts by mass, 93 parts by mass, 95 parts by mass, 97 parts by mass, 98 parts by mass) of polyamide elastomer and 0.01 to 5 parts by mass of nucleating agent (e.g., 0.1 parts by mass, 0.2 parts by mass, 0.5 parts by mass, 1 parts by mass, 1.5 parts by mass, 2 parts by mass, 2.5 parts by mass, 3 parts by mass, 3.5 parts by mass, 4 parts by mass or 4.5 parts by mass).

[0051] In one embodiment, the foaming material composition includes a polyamide elastomer, a nucleating agent and other additives. Further, the foaming material composition includes 80 to 100 parts by mass of a polyamide elastomer, 0 to 5 parts by mass of a nucleating agent, and 0.01 to 20 parts by mass (e.g., 0.1 parts by mass, 0.5 parts by mass, 1 parts by mass, 2 parts by mass, 3 parts by mass, 5 parts by mass, 8 parts by mass, 10 parts by mass, 12 parts by mass, 15 parts by mass or 18 parts by mass) of other additives.

[0052] In one embodiment, the nucleating agent includes one or more of nano-montmorillonite, nano-titanium dioxide, nano-calcium carbonate, nano-white carbon black, silicon dioxide, zinc oxide, attapulgite, palygorskite, talc, barium carbonate and graphene.

[0053] In one embodiment, other adjuvants include antioxidants and / or lubricants.

[0054] In one embodiment, the other auxiliary agent includes a foaming agent. Further, the foaming agent can be an existing chemical foaming agent.

[0055] In one embodiment, the foaming material composition includes 80 to 100 parts by mass of a polyamide elastomer, 0 to 5 parts by mass of a nucleating agent, and 0 to 2 parts by mass (e.g., 0.1 parts by mass, 0.2 parts by mass, 0.5 parts by mass, 0.8 parts by mass, 1 part by mass, 1.2 parts by mass, 1.5 parts by mass or 1.8 parts by mass) of an antioxidant; further, the antioxidant may be one or more of hindered phenol / amine antioxidants.

[0056] In one embodiment, the foaming material composition includes 80 to 100 parts by mass of a polyamide elastomer, 0 to 5 parts by mass of a nucleating agent, and 0 to 3 parts by mass (e.g., 0.1 parts by mass, 0.2 parts by mass, 0.5 parts by mass, 0.8 parts by mass, 1 parts by mass, 1.5 parts by mass, 2 parts by mass, or 2.5 parts by mass) of a lubricant; further, the lubricant may be one or more of bio-based rice bran wax, oxidized polyethylene wax, polyethylene wax, low molecular weight polypropylene wax, magnesium stearate, and calcium stearate.

[0057] In one embodiment, the processed foamed material composition may be in the form of particles, sheets, or other special shapes.

[0058] One embodiment of the present invention provides a polyamide elastomer foam material, which is obtained by foaming the above-mentioned foam material composition.

[0059] In one embodiment, the foaming material is a fully bio-based polyamide elastomer foaming material.

[0060] In one embodiment, the specific gravity of the foaming material is 40 to 500 kg / m 3 , further can be 65~250kg / m 3 , and further can be 78~110kg / m 3 , for example 80kg / m 3 , 90kg / m 3 , 100kg / m 3 , 110kg / m 3 , 120kg / m 3 、123kg / m 3 , 125kg / m 3 、142kg / m 3 、145kg / m 3 , 150kg / m 3 、155kg / m 3 、156kg / m 3 , 160kg / m 3 Among them, the specific gravity of the foaming material is measured according to GB / T 6343.

[0061] In one embodiment, the average cell diameter of the foaming material may be 50-200 μm, such as 58 μm, 60 μm, 80 μm, 90 μm, 100 μm, 110 μm, 112 μm, 120 μm, 150 μm, 180 μm, 190 μm, 195 μm, wherein the average cell diameter of the foaming material is obtained by SEM.

[0062] In one embodiment, the closed cell rate of the foamed material is greater than 92%, and may further be 93-97%, such as 94%, 95%, 96%, 98% or 99%. The closed cell rate of the foamed material is measured according to GB / T10799.

[0063] In one embodiment, the tear strength of the foamed material is 6.0-18.0 N / mm, and may further be 9.0-15.0 N / mm, such as 10 N / mm, 11 N / mm, 11.5 N / mm, 13 N / mm. The tear strength of the foamed material is measured according to ISO 34-1.

[0064] In one embodiment, the ball rebound rate of the foam material is 60% or more, further 75% or more, and further 79-86%, such as 79%, 80%, 81%, 82%, 86%, 88%, 90%. The ball rebound rate of the foam material is measured according to ASTM D2632.

[0065] In one embodiment, the hardness of the foam material when the thickness is 24 mm is 15-75C, and can further be 30-50C, for example, 32C, 35C, 40C, 43C, 45C, 47C, 50C, 55C, 60C, 61C, 65C, and 70C.

[0066] In one embodiment, the foamed material may be in the form of foamed beads (or particles), foamed sheets or foamed shaped materials.

[0067] One embodiment of the present invention provides a method for preparing the above-mentioned polyamide elastomer foam material, comprising the following steps:

[0068] S1: fully melt-blending a polyamide elastomer, a nucleating agent, and other optional additives according to a ratio to obtain a polyamide elastomer material of a specific shape;

[0069] S2: Fully infiltrating the physical foaming agent into the polyamide elastomer material, and performing physical foaming by means of pressure release or temperature increase to obtain a polyamide elastomer foaming material.

[0070] In one embodiment, the melt blending in step S1 can be performed by a known melt blending method, such as screw melt blending extrusion, internal mixing and open mixing, injection molding blending, etc.

[0071] In one embodiment, the polyamide elastomer material of the specific shape in step S1 may be in the form of beads (or particles), plates or special-shaped materials.

[0072] In one embodiment, the physical foaming in step S2 can be performed by a known foaming processing method, such as autoclave foaming, embryo mold foaming, injection molding foaming, extrusion foaming, compression molding foaming, etc.

[0073] In one embodiment, the physical foaming agent may be a liquefied gas, a supercritical fluid, etc., such as one or more of nitrogen, argon, carbon dioxide, low-boiling halogenated hydrocarbons or aliphatic hydrocarbons.

[0074] The polyamide elastomer foam material of one embodiment of the present invention can be used in the fields of sports shoes and clothing (such as foamed soles / insoles), wind power, rail transportation, new energy vehicles, cushioning packaging, aerospace, ships, sports equipment and construction.

[0075] In a polyamide elastomer according to an embodiment of the present invention, the hard segment polyamide and the soft segment polyester and / or polyether are all derived from bio-based materials, which can reduce dependence on petroleum resources and achieve green development.

[0076] According to one embodiment of the present invention, by regulating the mass ratio of hard segment raw materials and soft segment raw materials and selecting soft segment raw materials with specific hydroxyl values, a polyamide elastomer with uniform polymer chain length (narrow molecular weight distribution) can be obtained, and at the same time, a high content of strong hydrogen bonds is provided inside the polyamide. The interaction of hydrogen bonds gives the elastomer a higher melt viscosity and stable processing performance during the physical foaming process, so that the foamed product has a higher closed cell rate and excellent performance.

[0077] The polyamide elastomer foam material of one embodiment of the present invention has excellent properties, such as high closed cell rate (for example, greater than 92%), high tear strength, and uniform and dense cells.

[0078] In a polyamide elastomer foam material of one embodiment of the present invention, the hard segment and soft segment of the polyamide elastomer used are both derived from bio-based materials, so that the bio-based content is high and it has the advantages of low carbon, environmental protection and sustainable development.

[0079] The polyamide elastomer foam material of one embodiment of the present invention is a foamed molded body with excellent compression deformation performance and resilience and high closed cell rate. Due to its excellent compression deformation performance and resilience, it can be widely used in fields such as sports shoes and clothing (especially foamed soles / shoe insoles), cushioning materials, packaging materials, seat cushions or mattresses, automobile fields (automobile interior materials, automotive battery cushioning materials, etc.), aerospace and construction.

[0080] The following is a further description of the preparation of a polyamide elastomer and a foaming material according to an embodiment of the present invention in conjunction with examples. The test methods involved in each example and comparative example are as follows.

[0081] 1. Weight average molecular weight and molecular weight distribution

[0082] The weight average molecular weight and molecular weight distribution were measured by GPC.

[0083] 2. Melt mass flow rate

[0084] The melt mass flow rate of the polyamide elastomer is measured according to GB / T3682-2000, with the test temperature being 210° C. and the load being 2.5 kg.

[0085] 3. Tensile modulus

[0086] The tensile modulus of polyamide elastomers is measured according to ISO 527-1.

[0087] 4. Wear resistance

[0088] The abrasion resistance of polyamide elastomers is measured according to ISO 4649.

[0089] 5. Specific gravity

[0090] The specific gravity of the foamed material is measured according to GB / T 6343.

[0091] 6. Average cell diameter and cell size uniformity

[0092] The cell diameter and cell size uniformity of the foamed material were obtained by SEM.

[0093] 7. Closed-cell rate

[0094] The closed cell rate of the foamed material is measured according to GB / T 10799.

[0095] 8. Tear strength

[0096] The tear strength of the foamed material was measured according to ISO 34-1.

[0097] 9. Ball rebound rate

[0098] The ball rebound rate of the foam material is measured according to ASTM D2632.

[0099] 10. Bending resistance

[0100] The flexural resistance of the foamed material is measured according to SATRA TM161.

[0101] Example 1

[0102] Preparation of all-biobased polyamide elastomer A

[0103] In a nitrogen atmosphere, bio-based polyamide 410, adipic acid and pure water were mixed and added to a high-pressure reactor for melt polymerization. The temperature was raised to 200°C, the pressure was raised to 1.8 MPa, and the reaction was carried out for 4 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 80 Pa, and then the temperature was raised to 250°C for reaction for 2 hours to obtain carboxyl-terminated polyamide 410 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials bio-based polytrimethylene ether glycol and tetraethyl germanium were added to the above reaction system, evacuated to an absolute pressure of 80 Pa, and esterification reaction was carried out at 230°C for 3 hours to obtain a fully bio-based polyamide elastomer A.

[0104] Among them, the number average molecular weight of bio-based polyamide 410 is 1200, the molar ratio of adipic acid to bio-based polyamide 410 is 1.05:1, the molar ratio of hard segment raw material to soft segment raw material is 1:1, the mass ratio of hard segment raw material to soft segment raw material is 1.5:1, and the hydroxyl value of bio-based polytrimethylene ether glycol is 167 mgKOH / g.

[0105] Preparation of all-biobased polyamide elastomer foaming materials

[0106] 93 parts by weight of all-biobased polyamide elastomer A, 3 parts by weight of nano-titanium dioxide, 2 parts by weight of antioxidant 1010, and 2 parts by weight of magnesium stearate were put into an internal mixer at a processing temperature of 190°C. After uniform mixing and discharging, the mixture was moved to an open mixer for mixing and sheeting, and then placed for 24 hours for molding. The molding machine had a processing temperature of 200°C and a pressure of 6MPa. The sheet was placed in a molding machine for hot pressing, cold pressing, and cutting to obtain a all-biobased polyamide elastomer sheet A.

[0107] The all-biobased polyamide elastomer A sheet is put into a molding foaming machine at a processing temperature of 160°C, 20MPa nitrogen is introduced, and the pressure is quickly released after maintaining the pressure for 2 hours to obtain an all-biobased polyamide elastomer foamed board (or sheet).

[0108] Example 2

[0109] Preparation of all-biobased polyamide elastomer B

[0110] In a nitrogen atmosphere, bio-based polyamide 1012, suberic acid and pure water were mixed and added into a high-pressure reactor for melt polymerization. The temperature was raised to 190°C, the pressure was raised to 2MPa, and the reaction was continued for 5 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 100Pa, and then the temperature was raised to 240°C for reaction for 1.5 hours to obtain carboxyl-terminated polyamide 1012 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials bio-based polypropylene glycol and zirconium n-propoxide were added to the above reaction system, evacuated to an absolute pressure of 100Pa, and esterification reaction was carried out at 250°C for 2 hours to obtain a fully bio-based polyamide elastomer B.

[0111] Among them, the number average molecular weight of bio-based polyamide 1012 is 1600, the molar ratio of suberic acid to bio-based polyamide 1012 is 1.1:1, the molar ratio of hard segment raw material to soft segment raw material is 0.9:1.1, the mass ratio of hard segment raw material to soft segment raw material is 1:1, and the hydroxyl value of bio-based polypropylene glycol is 78 mgKOH / g.

[0112] Preparation of all-biobased polyamide elastomer foaming materials

[0113] 97 parts by weight of all-biobased polyamide elastomer B, 2 parts by weight of nano-montmorillonite, and 1 part by weight of bio-based rice bran wax are melt-blended by screw extrusion at a processing temperature of 195° C. to obtain a sheet of all-biobased polyamide elastomer composition B;

[0114] The all-bio-based polyamide elastomer composition B is put into a physical extrusion foaming machine, and supercritical carbon dioxide is injected into the middle and rear sections of the screw of the physical extrusion foaming machine through a physical foaming agent filling and metering system. The die head pressure is 12 MPa. After extrusion and pressure relief, an all-bio-based polyamide elastomer foamed sheet (or plate) is obtained.

[0115] Example 3

[0116] Preparation of all-biobased polyamide elastomer C

[0117] In a nitrogen atmosphere, bio-based polyamide 1010, terephthalic acid and pure water were mixed and added into a high-pressure reactor for melt polymerization. The temperature was raised to 210°C, the pressure was raised to 3MPa, and the reaction was continued for 3.5 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 90Pa, and then the temperature was raised to 270°C for reaction for 2.5 hours to obtain carboxyl-terminated polyamide 1010 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials, bio-based polytetrahydrofuran ether diol and ethylene glycol antimony, were added to the above reaction system, evacuated to an absolute pressure of 150Pa, and esterification reaction was carried out at 260°C for 4 hours to obtain a fully bio-based polyamide elastomer C.

[0118] Among them, the number average molecular weight of bio-based polyamide 1010 is 1800, the molar ratio of terephthalic acid to bio-based polyamide 1010 is 1.05:1, the molar ratio of hard segment raw material to soft segment raw material is 1:1, the mass ratio of hard segment raw material to soft segment raw material is 2:1, and the hydroxyl value of bio-based polytetramethylene ether diol is 141 mgKOH / g.

[0119] Preparation of all-biobased polyamide elastomer foaming materials

[0120] 98 parts by weight of all-biobased polyamide elastomer C and 2 parts by weight of nano-calcium carbonate are added into an injection molding machine at a processing temperature of 210° C., and injection molding is performed to obtain an all-biobased polyamide elastomer profile C;

[0121] The all-bio-based polyamide elastomer profile C was put into a physical foaming autoclave, and 10MPa supercritical carbon dioxide and nitrogen were introduced in a 1:1 ratio. After saturation at 100°C for 4 hours, the profile C was taken out and placed in an air atmosphere at 150°C for heating and foaming to obtain a all-bio-based polyamide elastomer foamed profile.

[0122] Example 4

[0123] Preparation of all-biobased polyamide elastomer D

[0124] In a nitrogen atmosphere, bio-based polyamide 11, sebacic acid and pure water were mixed and added into a high-pressure reactor for melt polymerization. The temperature was raised to 180°C, the pressure was raised to 3MPa, and the reaction was continued for 5 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 120Pa, and then the temperature was raised to 260°C for reaction for 4 hours to obtain carboxyl-terminated polyamide 11 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials, bio-based poly(1,3-propylene sebacic acid) and tetrabutyl titanate, were added to the above reaction system, evacuated to an absolute pressure of 70Pa, and esterification reaction was carried out at 240°C for 5 hours to obtain a fully bio-based polyamide elastomer D.

[0125] Among them, the number average molecular weight of bio-based polyamide 11 is 2000, the molar ratio of sebacic acid to bio-based polyamide 11 is 1.1:1, the molar ratio of hard segment raw material to soft segment raw material is 1.1:0.9, the mass ratio of hard segment raw material to soft segment raw material is 2.5:1, and the hydroxyl value of bio-based poly 1,3-propylene glycol sebacic acid ester is 123 mgKOH / g.

[0126] Preparation of all-biobased polyamide elastomer foaming materials

[0127] 95 parts by weight of all-biobased polyamide elastomer D, 3 parts by weight of silica, and 2 parts by weight of polyethylene wax are melt-blended through screw extrusion at a processing temperature of 200° C. The all-biobased polyamide elastomer particles D are obtained after stranding and pelletizing.

[0128] The all-biobased polyamide elastomer particles D were added into the injection molding foaming machine, and supercritical nitrogen was introduced. The injection pressure was 170 MPa, and the pressure was maintained at 170°C for 1 min, then the mold was opened and the pressure was released to obtain the all-biobased polyamide elastomer foamed profile.

[0129] Comparative Example 1

[0130] Preparation of all-biobased polyamide elastomer E

[0131] In a nitrogen atmosphere, bio-based polyamide 410, adipic acid and pure water were mixed and added to a high-pressure reactor for melt polymerization. The temperature was raised to 200°C, the pressure was raised to 1.8 MPa, and the reaction was carried out for 4 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 80 Pa, and then the temperature was raised to 250°C for reaction for 2 hours to obtain carboxyl-terminated polyamide 410 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials bio-based polytrimethylene ether glycol and tetraethyl germanium were added to the above reaction system, evacuated to an absolute pressure of 80 Pa, and esterification reaction was carried out at 230°C for 3 hours to obtain a fully bio-based polyamide elastomer E.

[0132] Among them, the number average molecular weight of bio-based polyamide 410 is 800, the amount ratio of the hard segment raw material to the soft segment raw material is 1:1.8, the mass ratio of the hard segment raw material to the soft segment raw material is 1:2.5, and the hydroxyl value of the soft segment raw material is 20 mgKOH / g.

[0133] Preparation of all-biobased polyamide elastomer foaming materials

[0134] 93 parts by weight of all-biobased polyamide elastomer E, 3 parts by weight of nano-titanium dioxide, 2 parts by weight of antioxidant 1010, and 2 parts of magnesium stearate were put into an internal mixer at a processing temperature of 190°C. After uniform mixing and discharging, the mixture was moved to an open mixer for mixing and sheeting. After standing for 24 hours, the mixture was molded at a processing temperature of 200°C and a pressure of 6MPa. The sheet was placed in the molding machine for hot pressing, cold pressing, and cutting to obtain an all-biobased polyamide elastomer sheet E.

[0135] The all-biobased polyamide elastomer sheet E was put into a molding foaming machine at a processing temperature of 160°C, and 20MPa nitrogen was introduced. After maintaining the pressure for 2 hours, the pressure was quickly released to obtain an all-biobased polyamide elastomer foamed plate (or sheet).

[0136] Comparative Example 2

[0137] Preparation of all-biobased polyamide elastomer F

[0138] In a nitrogen atmosphere, bio-based polyamide 1012, suberic acid and pure water were mixed and added into a high-pressure reactor for melt polymerization. The temperature was raised to 190°C, the pressure was raised to 2MPa, and the reaction was continued for 5 hours. The pressure was released to normal pressure, evacuated to an absolute pressure of 100Pa, and then the temperature was raised to 240°C for reaction for 1.5 hours to obtain carboxyl-terminated polyamide 1012 (hard segment raw material). In a nitrogen atmosphere, the soft segment raw materials bio-based polypropylene glycol and zirconium n-propoxide were added to the above reaction system, evacuated to an absolute pressure of 100Pa, and esterification reaction was carried out at 250°C for 2 hours to obtain a fully bio-based polyamide elastomer F.

[0139] Among them, the number average molecular weight of bio-based polyamide 1012 is 1600, the molar ratio of the hard segment raw material to the soft segment raw material is 3:1, the mass ratio of the hard segment raw material to the soft segment raw material is 3.5:1, and the hydroxyl value of the soft segment raw material is 260 mgKOH / g.

[0140] Preparation of all-biobased polyamide elastomer foaming materials

[0141] 97 parts by weight of all-biobased polyamide elastomer F, 2 parts by weight of nano-montmorillonite, and 1 part by weight of bio-based rice bran wax are melt-blended by screw extrusion at a processing temperature of 195° C. to obtain all-biobased polyamide elastomer F;

[0142] The fully bio-based polyamide elastomer F is put into a physical extrusion foaming machine, and supercritical carbon dioxide is injected into the middle and rear sections of the screw of the physical extrusion foaming machine through a physical foaming agent filling and metering system. The die head pressure is 12 MPa. After extrusion and pressure relief, a fully bio-based polyamide elastomer foamed sheet (or plate) is obtained.

[0143] Comparative Example 3

[0144] In a nitrogen atmosphere, 5000g of sebacic acid, 6020g of deionized water, 2526g of pentamethylenediamine, 200g of adipic acid, 75g of sodium hypophosphite, and 90g of antioxidant H10 were added to a high-pressure reactor to prepare a polyamide salt solution. The oil bath was heated and the pressure was increased to 1.7MPa for high-pressure prepolymerization for 120min, and the heating was continued. The pressure was released to normal pressure within 40min, and the pressure was evacuated to -0.06MPa for prepolymerization for 20min, and then nitrogen was filled to a slight positive pressure, and the product prepolymer was obtained after discharging and drying. In a nitrogen state, 6051g of the above prepolymer with a number average molecular weight of 4000, 1467g of PTMEG with a number average molecular weight of 1000, and 36g of tetrabutyl zirconate were added to the reactor. Turn on the heating, and start stirring when the temperature in the kettle reaches 220°C. After vacuum stirring for 30 minutes, evacuate to -80 kPa. After 1 hour, heat to 240°C, evacuate to 200 Pa, and carry out polymerization reaction for 5 hours to obtain polyamide elastomer G.

[0145] Preparation of polyamide elastomer foaming material

[0146] 97 parts by weight of all-biobased polyamide elastomer G, 2 parts by weight of nano-calcium carbonate, and 1 part by weight of zinc oxide were added into an injection molding machine at a processing temperature of 210° C., and injection molding was performed to obtain all-biobased polyamide elastomer profile G;

[0147] The all-bio-based polyamide elastomer profile G was put into a physical foaming autoclave, and 10MPa supercritical carbon dioxide and nitrogen were introduced in a 1:1 ratio. After saturation at 100°C for 4 hours, the profile G was taken out and placed in an air atmosphere at 150°C for heating and foaming to obtain the all-bio-based polyamide elastomer foamed profile G.

[0148] Comparative Example 4

[0149] Under nitrogen atmosphere, 8 kg PA510 salt, 2 kg polyetheramine-((OCH2CH2)2(OCH2CH2CH2CH2)2) 10 NH2 and 5 kg of water were added to a high-pressure reactor and mixed, and the temperature was raised to 220°C for reaction for 4 hours, and then the pressure was reduced to normal pressure by removing water vapor, and the reaction was continued for another 2 hours to obtain a polyamide elastomer H;

[0150] Preparation of polyamide elastomer foaming material

[0151] The polyamide elastomer H was put into a physical foaming autoclave, 20 MPa nitrogen was introduced, heated to 135°C and maintained at pressure for 4 hours, and then the pressure was quickly released for 12 seconds to obtain a polyamide elastomer foaming material.

[0152] The bio-based polyamide elastomers and foamed materials prepared in the embodiments and comparative examples were subjected to relevant performance tests, and the test results are shown in Tables 1 and 2.

[0153] Table 1 Performance results of polyamide elastomers in various embodiments and comparative examples

[0154]

[0155] Table 2 Performance results of polyamide elastomer foam materials of various embodiments and comparative examples

[0156]

[0157]

[0158] According to the test results in Tables 1 and 2, compared with the polyamide elastomers of Comparative Examples 1 to 4, the polyamide elastomers of Examples 1 to 4 of the present invention have a narrower molecular weight distribution, a higher melt mass flow rate, and better mechanical properties and wear resistance; this enables the elastomer to have a higher melt viscosity and stable processing performance during the physical foaming process.

[0159] Further, the difference between Example 1 and Comparative Example 1 and between Example 2 and Comparative Example 2 is mainly that: the molar ratio of the hard segment raw material to the soft segment raw material of Examples 1 and 2 is in the range of (2-3):(2-3), the mass ratio is in the range of (1-3):1, and the hydroxyl value of the soft segment raw material is in the range of 30-600 mgKOH / g; while the above parameters of Comparative Examples 1 and 2 are not in or not completely in the above range. In addition to the above performance differences, the foaming materials of Examples 1 and 2 have obvious differences from the foaming materials of Comparative Examples 1 and 2 in terms of cell morphology and the like.

[0160] Specifically, refer to Figures 1 to 4 It can be seen that the internal cell size difference of the polyamide elastomer foam material of comparative example 1 is very large, there are problems of cell merging or rupture, and the density is high. Although the cell size uniformity of the polyamide elastomer foam material of comparative example 2 is improved, the cell wall is thin, wrinkles are easily generated, the internal cells are mostly broken, the closed cell rate is low, and the density is too high. The internal cells of the polyamide elastomer foam materials of Examples 1 to 4 of the present invention are full and dense, uniform in size, and the cell wall has strong support, and it is not easy to have problems such as broken or merged cells. Therefore, the foamed products have low density, high closed cell rate, high resilience, and excellent tearing and bending resistance.

[0161] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0162] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A polyamide elastomer, comprising a hard segment and a soft segment, wherein the hard segment comprises a polyamide block, and the soft segment comprises a polyether block and / or a polyester block; wherein: The molar ratio of the hard segment to the soft segment is (2-3):(2-3); the number average molecular weight of the hard segment is 1000-3000, and the mass ratio of the hard segment to the soft segment is (1-3):1; The polyamide elastomer is prepared by reacting a hard segment raw material and a soft segment raw material, and the hydroxyl value of the soft segment raw material is 30-600 mgKOH / g.

2. The polyamide elastomer according to claim 1, having a weight average molecular weight of 65,000 to 120,000; and / or The molecular weight distribution of the polyamide elastomer is 0.7 to 3.5; and / or, The melt mass flow rate of the polyamide elastomer at 210° C. and 2.5 kg is 10 to 90 g / 10 min; and / or, The tensile modulus of the polyamide elastomer is 110 to 160 MPa; and / or, The hydroxyl value of the soft segment raw material is 70 to 170 mgKOH / g.

3. The polyamide elastomer according to claim 1, wherein The hard segment raw material comprises polyamide, and the soft segment raw material comprises hydroxyl-terminated polyester polyol and / or polyether polyol; and / or, The weight average molecular weight of the polyamide elastomer is 75000 to 101000; and / or, The molecular weight distribution of the polyamide elastomer is 1.5 to 2.1; and / or, The melt mass flow rate of the polyamide elastomer at 210° C. and 2.5 kg is 20 to 75 g / 10 min.

4. The polyamide elastomer according to claim 3, wherein The polyamide is a bio-based polyamide; and / or, the polyester polyol is a bio-based polyester polyol; and / or, the polyether polyol is a bio-based polyether polyol; and / or, The hard segment raw material includes one or more of polyamide 13, polyamide 12, polyamide 11, polyamide 10, polyamide 10T, polyamide 1010, polyamide 510, polyamide 610, polyamide 1012, polyamide 410, polyamide 1012, polyamide 46, and polyamide 56; and / or, The soft segment raw material includes one or more of polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polytrimethylene ether glycol, polysuccinate-1,3-propylene glycol ester glycol, polybutylene succinate, polysuccinate-1,3-propylene glycol ester, and polybutylene sebacate.

5. A foaming material composition comprising the polyamide elastomer according to any one of claims 1 to 4 and an additive.

6. The composition according to claim 5, wherein The additives include nucleating agents and optionally other auxiliary agents.

7. The composition according to claim 6, comprising 80 to 100 parts by mass of the polyamide elastomer, 0.01 to 5 parts by mass of a nucleating agent and 0 to 20 parts by mass of other additives; and / or, The nucleating agent includes one or more of nano-montmorillonite, nano-titanium dioxide, nano-calcium carbonate, nano-white carbon black, silicon dioxide, zinc oxide, attapulgite, palygorskite, talc, barium carbonate and graphene; and / or, The other additives include antioxidants and / or lubricants; and / or, The additives include a blowing agent.

8. A polyamide elastomer foam material, obtained by foaming the foam material composition according to any one of claims 5 to 7.

9. The foam material according to claim 8, having a specific gravity of 40 to 500 kg / m 3 , further can be 65~250kg / m 3 , and further can be 78~110kg / m 3 and / or, The closed cell rate of the foaming material is greater than 92%, and may further be 93-97%; and / or, The average cell diameter of the foaming material is 50 to 200 μm; and / or, The tear strength of the foam material is 6.0 to 18.0 N / mm, and can further be 9.0 to 15.0 N / mm; The ball rebound rate of the foam material is 60% or more, further 75% or more, and further 79-86%; and / or, The hardness of the foam material when the thickness is 24 mm is 15-75C, and can further be 30-50C.

10. Use of the foaming material according to claim 8 or 9 in sports shoes and clothing, cushioning materials, packaging materials, seat cushions, mattresses, automobiles, aerospace or construction.

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