A modified thermoplastic elastomer color-changing yoga mat material and preparation method thereof

Abstract

The present application relates to the field of polymer materials, and specifically discloses a modified thermoplastic elastomer color-changing yoga mat material and a preparation method thereof. A modified thermoplastic elastomer color-changing yoga mat material comprises the following raw materials in parts by weight: 30-40 parts of thermoplastic polyester elastomer, 10-20 parts of styrene-butadiene block copolymer, 1-5 parts of color-changing powder, 3-5 parts of foaming agent, 0.5-0.8 parts of nano zinc oxide, 0.6-0.9 parts of epoxy crosslinking agent, and 0.8-1.2 parts of isocyanate crosslinking agent. A modified thermoplastic elastomer color-changing yoga mat material of the present application is a thermoplastic polyester elastomer and a styrene-butadiene block copolymer blended and modified, and epoxy crosslinking agent and isocyanate crosslinking agent are compounded to form a yoga mat material system with a high degree of crosslinking, so that the prepared yoga mat has excellent resilience, tensile strength and tear resistance.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and in particular to a modified thermoplastic elastomer color-changing yoga mat material and a preparation method thereof. Background Art

[0002] Thermoplastic elastomer TPE not only maintains the excellent properties of traditional cross-linked vulcanized rubber such as high elasticity, aging resistance, and oil resistance, but also has the advantages of easy processing of ordinary plastics. Therefore, thermoplastic elastomer TPE has gradually become a more humane and high-grade new polymer synthetic material.

[0003] In today's society, yoga has become a fashionable sport, suitable for all kinds of people. A wide variety of yoga mats are available for practitioners. Yoga mats are soft and flexible, and common materials include TPE, PVC, and EVA. TPE is a relatively high-end material among yoga mats. It contains no chlorides or metal elements, is anti-static, and is easy to clean, making it suitable for travel.

[0004] In order to maintain a certain elasticity, TPE yoga mats often use a foaming agent to foam the TPE material. The foaming agent has a pore-opening effect in the TPE material, producing a certain amount of bubbles. However, these bubbles can easily reduce the strength and toughness of the yoga mat. The tear resistance of the foamed yoga mat product is significantly reduced, which ultimately leads to a significant shortening of the service life of the yoga mat. Summary of the Invention

[0005] In order to improve the toughness and tear resistance of the yoga mat after foaming, the present application provides a modified thermoplastic elastomer color-changing yoga mat material and a preparation method thereof.

[0006] In a first aspect, the present application provides a modified thermoplastic elastomer color-changing yoga mat material, which adopts the following technical solution:

[0007] A modified thermoplastic elastomer color-changing yoga mat material comprises the following raw materials in parts by weight: 30-40 parts of thermoplastic polyester elastomer, 10-20 parts of styrene-butadiene block copolymer, 1-5 parts of color-changing powder, 3-5 parts of foaming agent, 0.5-0.8 parts of nano zinc oxide, 0.6-0.9 parts of epoxy crosslinking agent, and 0.8-1.2 parts of isocyanate crosslinking agent.

[0008] By adopting the above technical solution, a thermoplastic polyester elastomer and styrene-butadiene block copolymer are blended and modified, resulting in a yoga mat material with excellent tensile strength, toughness, and resilience. Furthermore, the thermoplastic polyester elastomer also exhibits excellent fatigue and tear resistance, and can be compounded with the styrene-butadiene block copolymer, resulting in a yoga mat material with a long service life and flex fatigue resistance. Nano-zinc oxide, with its high modulus and large specific surface area, can fully contact the thermoplastic polyester elastomer and styrene-butadiene block copolymer, dispersing stress within the yoga mat material system, thereby enhancing and toughening the yoga mat material.

[0009] Thermoplastic polyester elastomers are modified using epoxy and isocyanate crosslinkers. The carboxyl and hydroxyl groups at both ends of the thermoplastic polyester elastomer react and polymerize with the epoxy and isocyanate crosslinkers, increasing the molecular chain length of the thermoplastic polyester elastomer and transforming the linear structure of the thermoplastic polyester elastomer into a network structure. This improves the crosslinking degree and tear resistance of the thermoplastic polyester elastomer in the yoga mat material system, and increases the surface density and tensile strength of the yoga mat material after foaming. The epoxy and isocyanate crosslinkers melt with the thermoplastic polyester elastomer, increasing the melt strength of the thermoplastic polyester elastomer and allowing the gas in the yoga mat material to be encapsulated by the melt after foaming, forming closed pores. This reduces defects caused by cell rupture and cross-bubble crosslinking, resulting in a uniform and regular pore structure and more even pore distribution in the yoga mat material system.

[0010] Preferably, the foaming agent is a mixture of azodicarbonamide, sodium bicarbonate and calcium stearate, and the mass ratio of azodicarbonamide, sodium bicarbonate and calcium stearate is 1:(0.5-0.8):(2-3).

[0011] By adopting the above technical solution, calcium stearate contains active divalent metal ions, which can form a chelate with the azo group in the azodicarbonamide foaming agent, lowering the decomposition temperature of azodicarbonamide while activating its decomposition, improving the foaming efficiency of the foaming agent and promoting good resilience in the resulting yoga mat. Sodium bicarbonate absorbs a large amount of energy during the gas decomposition process, balancing the heat generated by the decomposition of azodicarbonamide, further lowering its decomposition temperature. This reduces local overheating during foaming of the yoga mat material, which can cause scorching and cell rupture in the internal material, thereby improving the foaming effect of the foaming agent. The combination of azodicarbonamide, calcium stearate, and sodium bicarbonate results in excellent resilience and toughness in the foamed yoga mat material.

[0012] Preferably, the color-changing yoga mat material also includes 1-2.5 parts of polypropylene.

[0013] By adopting this technical solution, the helical polypropylene macromolecule chains are tightly entangled with the thermoplastic polyester elastomer molecular chains, improving the elastic recovery rate and elongation at break of the thermoplastic polyester elastomer. The appropriate amount of polypropylene added to the thermoplastic polyester elastomer acts as a nucleating agent, promoting the crystallization of the thermoplastic polyester elastomer's hard segments. These tiny crystals can form nodes with the thermoplastic polyester elastomer's soft segments, thereby improving the yoga mat material's resilience and tear resistance.

[0014] Preferably, the color-changing yoga mat material raw material further includes 0.3-0.8 parts of polypropylene grafted glycidyl methacrylate.

[0015] By adopting the above technical solution, polypropylene grafted glycidyl methacrylate is added to the yoga mat material system, which promotes better compatibility between thermoplastic polyester elastomer and polypropylene, improves the degree of cross-linking between thermoplastic polyester elastomer, styrene-butadiene block copolymer and polypropylene, improves the compatibility of the yoga mat material system, and further improves the tear strength and elastic recovery performance of the yoga mat.

[0016] Preferably, the particle size of the nano zinc oxide is 50nm-100nm.

[0017] By adopting the above technical solution, the particle size of nano zinc oxide is controlled within a reasonable range. Nano zinc oxide has a larger specific surface area. Finer nano zinc oxide is more conducive to the rapid decomposition of the foaming agent, which enables nano zinc oxide to have a better activation effect in the yoga mat material system.

[0018] Preferably, the molecular weight of the epoxy crosslinking agent is 7000-8000.

[0019] By adopting the above technical solution, the molecular weight of the epoxy cross-linking agent is controlled within a higher range, which can improve the flexibility of the epoxy cross-linking agent, increase the number of single bonds that can rotate within the cross-linking agent, reduce the hardening, brittleness and cracking of the yoga mat, and improve the breaking strength and elongation of the yoga mat.

[0020] In a second aspect, the present application provides a method for preparing a modified thermoplastic elastomer color-changing yoga mat material, using the following technical solution:

[0021] A method for preparing a modified thermoplastic elastomer color-changing yoga mat material comprises the following specific steps:

[0022] Thermoplastic polyester elastomer and styrene-butadiene block copolymer are mixed, and then a foaming agent, an epoxy cross-linking agent, an isocyanate cross-linking agent and a color-changing powder are added and kneaded to form a mixture. Finally, the mixture is open-milled, sheeted and foamed to obtain a modified thermoplastic elastomer color-changing yoga mat material.

[0023] Preferably, the banburying temperature is 100-110°C, and the foaming temperature is 160-170°C.

[0024] By adopting the above technical solution, the modified thermoplastic elastomer color-changing yoga mat material is prepared, and after the components are cross-linked with each other, foaming is performed, so that the prepared yoga mat has excellent elastic recovery performance, toughness and tear resistance.

[0025] In summary, this application has the following beneficial effects:

[0026] 1. The present invention utilizes a thermoplastic polyester elastomer and a styrene-butadiene block copolymer for blending and modification, resulting in a yoga mat having excellent elastic recovery, toughness, and tear resistance. The thermoplastic polyester elastomer is cross-linked and modified using an epoxy cross-linking agent and an isocyanate cross-linking agent, thereby forming a network structure within the yoga mat material system, increasing the degree of cross-linking within the yoga mat material system and resulting in excellent tear resistance and toughness.

[0027] 2. In this application, azodicarbonamide, calcium stearate and sodium bicarbonate are used to form a foaming agent, which reduces the decomposition temperature of azodicarbonamide, balances the heat during the decomposition of azodicarbonamide, improves the foaming efficiency of the foaming agent, reduces the phenomenon of local overheating during the foaming process of the yoga mat material, and enables the foamed yoga mat to have excellent rebound performance and toughness. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the embodiments.

[0029] The thermoplastic polyester elastomer is selected as Hytrel 3548 thermoplastic polyester elastomer.

[0030] The isocyanate crosslinker selected isocyanate crosslinker BI7950 from Shanghai Juncai Material Technology Co., Ltd.

[0031] The styrene-butadiene block copolymer is selected as styrene-butadiene block copolymer KR03.

[0032] The polypropylene grade is F280.

[0033] The color-changing powder selected is 032C from Shenzhen Bianse Technology Co., Ltd.

[0034] Example

[0035] Example 1

[0036] A modified thermoplastic elastomer color-changing yoga mat material comprises the following raw materials by weight: 35 kg of thermoplastic polyester elastomer, 15 kg of styrene-butadiene block copolymer, 3 kg of color-changing powder, 4 kg of foaming agent, 0.7 kg of nano-zinc oxide, 0.8 kg of epoxy crosslinking agent, and 1 kg of isocyanate crosslinking agent. The nano-zinc oxide has a particle size of 70-80 nm, the epoxy crosslinking agent has a molecular weight of 7500, and the foaming agent is a mixture of azodicarbonamide, sodium bicarbonate, and calcium stearate in a mass ratio of 1:0.7:2.5.

[0037] The preparation method of the modified thermoplastic elastomer color-changing yoga mat material comprises the following specific steps:

[0038] S1: Thermoplastic polyester elastomer and styrene-butadiene block copolymer were mixed and kneaded at 105°C for 10 minutes. Then, a foaming agent, zinc oxide, epoxy crosslinking agent and isocyanate crosslinking agent were added and kneaded for another 10 minutes. Finally, a color-changing powder was added and kneaded for another 5 minutes to form a mixture.

[0039] S2: The mixed material is fed into an open mill for shearing and mixing, and then sheeted to form a yoga mat sheet. The yoga mat sheet is then foamed at 165° C. for 10 minutes to obtain a modified thermoplastic elastomer color-changing yoga mat material.

[0040] Example 2

[0041] Example 2 differs from Example 1 in that the raw materials for the modified thermoplastic elastomer color-changing yoga mat include 30 kg of thermoplastic polyester elastomer, 20 kg of styrene-butadiene block copolymer, 1 kg of color-changing powder, 3 kg of foaming agent, 0.5 kg of nano-zinc oxide, 0.6 kg of epoxy crosslinking agent, and 1.2 kg of isocyanate crosslinking agent. The nano-zinc oxide has a particle size of 50 nm to 60 nm, the epoxy crosslinking agent has a molecular weight of 7,000, and the foaming agent is a mixture of azodicarbonamide, sodium bicarbonate, and calcium stearate in a mass ratio of 1:0.5:3.

[0042] Example 3

[0043] Example 3 differs from Example 1 in that the raw materials for the modified thermoplastic elastomer color-changing yoga mat include 40 kg of thermoplastic polyester elastomer, 10 kg of styrene-butadiene block copolymer, 5 kg of color-changing powder, 5 kg of foaming agent, 0.8 kg of nano-zinc oxide, 0.9 kg of epoxy crosslinking agent, and 0.8 kg of isocyanate crosslinking agent. The nano-zinc oxide has a particle size of 90 nm to 100 nm, the epoxy crosslinking agent has a molecular weight of 8,000, and the foaming agent is a mixture of azodicarbonamide, sodium bicarbonate, and calcium stearate in a mass ratio of 1:0.8:2.

[0044] Example 4

[0045] The difference between Example 4 and Example 1 is that the foaming agent in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is a mixture of azodicarbonamide and calcium stearate in a mass ratio of 1:2.5.

[0046] Example 5

[0047] The difference between Example 5 and Example 1 is that the foaming agent in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is a mixture of azodicarbonamide and sodium bicarbonate in a mass ratio of 1:0.7.

[0048] Example 6

[0049] The difference between Example 6 and Example 1 is that the foaming agent in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is azodicarbonamide.

[0050] Example 7

[0051] The difference between Example 7 and Example 1 is that the raw materials of the modified thermoplastic elastomer color-changing yoga mat material also include 1.8 kg of polypropylene.

[0052] The preparation method of the modified thermoplastic elastomer color-changing yoga mat material comprises the following specific steps:

[0053] S1: Thermoplastic polyester elastomer, polypropylene and styrene-butadiene block copolymer were mixed and kneaded at 105°C for 10 minutes, and then a foaming agent, zinc oxide, epoxy crosslinking agent and isocyanate crosslinking agent were added and kneaded for another 10 minutes. Finally, a color-changing powder was added and kneaded for another 5 minutes to form a mixture;

[0054] S2: The mixed material is fed into an open mill for shearing and mixing, and then sheeted to form a yoga mat sheet. The yoga mat sheet is then foamed at 165° C. for 10 minutes to obtain a modified thermoplastic elastomer color-changing yoga mat material.

[0055] Example 8

[0056] The difference between Example 8 and Example 7 is that the amount of polypropylene used in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is 1 kg.

[0057] Example 9

[0058] The difference between Example 9 and Example 7 is that the amount of polypropylene used in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is 2.5 kg.

[0059] Example 10

[0060] The difference between Example 10 and Example 7 is that the raw material of the modified thermoplastic elastomer color-changing yoga mat material further includes 0.5 kg of polypropylene grafted glycidyl methacrylate.

[0061] The preparation method of the modified thermoplastic elastomer color-changing yoga mat material comprises the following specific steps:

[0062] S1: Thermoplastic polyester elastomer, polypropylene, polypropylene grafted glycidyl methacrylate and styrene-butadiene block copolymer were mixed and kneaded at 105°C for 10 minutes, and then a foaming agent, zinc oxide, epoxy crosslinking agent and isocyanate crosslinking agent were added and kneaded for another 10 minutes. Finally, a color-changing powder was added and kneaded for another 5 minutes to form a mixture;

[0063] S2: The mixed material is fed into an open mill for shearing and mixing, and then sheeted to form a yoga mat sheet. The yoga mat sheet is then foamed at 165° C. for 10 minutes to obtain a modified thermoplastic elastomer color-changing yoga mat material.

[0064] Example 11

[0065] The difference between Example 11 and Example 10 is that the amount of polypropylene grafted glycidyl methacrylate used in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is 0.3 kg.

[0066] Example 12

[0067] The difference between Example 12 and Example 10 is that the amount of polypropylene grafted glycidyl methacrylate used in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is 0.8 kg.

[0068] Example 13

[0069] The difference between Example 13 and Example 1 is that the molecular weight of the epoxy crosslinking agent in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is 4000.

[0070] Comparative Example

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 1 is that no isocyanate cross-linking agent is used in the raw materials of the modified thermoplastic elastomer color-changing yoga mat material.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 1 is that no epoxy crosslinking agent is used in the raw materials of the modified thermoplastic elastomer color-changing yoga mat material.

[0075] Comparative Example 3

[0076] The difference between Comparative Example 3 and Example 1 is that no epoxy crosslinking agent and no isocyanate crosslinking agent are used in the raw materials of the modified thermoplastic elastomer color-changing yoga mat material.

[0077] Comparative Example 4

[0078] The difference between Comparative Example 4 and Example 1 is that the nano zinc oxide in the raw material of the modified thermoplastic elastomer color-changing yoga mat material is replaced by an equal amount of zinc oxide, and the particle size of the zinc oxide is 0.2 μm-0.3 μm.

[0079] Performance testing

[0080] The following performance tests were performed on the modified thermoplastic elastomer color-changing yoga mat materials provided in Examples 1-13 and Comparative Examples 1-4 of the present application. The specific test results are shown in Table 1.

[0081] Detection method

[0082] 1. Tensile strength

[0083] With reference to the standard of GB / T10654-2001 “Determination of tensile strength and elongation at break of porous polymer elastic materials”, the tensile strength of the modified thermoplastic elastomer color-changing yoga mat material prepared in this application was tested.

[0084] 2. Tear strength

[0085] The tear strength of the modified thermoplastic elastomer color-changing yoga mat material prepared in this application was tested with reference to ASTM D624 "Standard Test Method for Tear Strength of General-Purpose Vulcanized Rubber and Thermoplastic Elastomers".

[0086] 3. Rebound performance

[0087] The rebound performance of the modified thermoplastic elastomer color-changing yoga mat material prepared in this application was tested with reference to the standard of GB / T6670-2008 "Determination of rebound performance of soft foam polymeric materials by falling ball method".

[0088] Table 1: Performance test data table

[0089]

[0090] It can be seen from the performance test results that the yoga mat material prepared in this application has excellent resilience, and the yoga mat also has high tensile strength and tear resistance. In Examples 1-3, the content of each component in the yoga mat material raw materials is different, among which the comprehensive performance of Example 1 is better. By comparing the performance of Examples 4-6 with that of Example 1, it can be seen that in this application, calcium stearate and sodium bicarbonate are compounded with azodicarbonamide, and calcium stearate and sodium bicarbonate activate and balance the heat of azodicarbonamide, thereby improving the foaming effect of the foaming agent in the yoga mat material system, reducing the excessive heat generated during foaming, and damaging the strength of the formed yoga mat, thereby further promoting the formed yoga mat to have excellent resilience and toughness.

[0091] In Examples 7-9, different amounts of polypropylene were added to the yoga mat material system. From the performance test results, it can be seen that the tear resistance of the prepared yoga mats was significantly improved, further demonstrating that polypropylene has a significant promoting effect on the toughness and tear resistance of the yoga mat.

[0092] In Examples 10-12, different amounts of polypropylene grafted glycidyl methacrylate were added to the yoga mat material system. From the performance test results, it can be seen that the comprehensive performance of the prepared yoga mats is improved. This shows that polypropylene grafted glycidyl methacrylate not only promotes the bonding between the thermoplastic polyester elastomer and polypropylene, but also polypropylene grafted glycidyl methacrylate is added to the yoga mat material system as a compatibilizer, which can also play an important role in promoting the compatibility between the components in the yoga mat material system.

[0093] In Example 13, a lower molecular weight epoxy crosslinker was used. Performance test results show that the yoga mat's tear resistance was slightly reduced. This may be because the low molecular weight epoxy crosslinker has a lower toughening effect on the yoga mat, making the resulting yoga mat brittle and harder, thus reducing the yoga mat's tear resistance.

[0094] By comparing the performance test results of Comparative Examples 1-3 with those of Example 1, it can be seen that the lack of any component of the epoxy crosslinker and the isocyanate crosslinker in the present application will affect the degree of crosslinking of the yoga mat material system, thereby reducing the flexibility and tear resistance of the yoga mat.

[0095] By comparing the performance test results of Comparative Example 4 and Example 1, it can be seen that when conventional zinc oxide is used instead of nano zinc oxide, the tear resistance and rebound performance of the yoga mat will be significantly reduced. This may be because nano zinc oxide has a larger specific surface area and higher surface energy, which can better promote the activation of azodicarbonamide.

[0096] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A modified thermoplastic elastomer color-changing yoga mat material, characterized in that: The invention comprises the following raw materials in parts by weight: 30-40 parts of thermoplastic polyester elastomer, 10-20 parts of styrene-butadiene block copolymer, 1-5 parts of color-changing powder, 3-5 parts of foaming agent, 0.5-0.8 parts of nano zinc oxide, 0.6-0.9 parts of epoxy crosslinking agent, 0.8-1.2 parts of isocyanate crosslinking agent, 1-2.5 parts of polypropylene, and 0.3-0.8 parts of polypropylene grafted glycidyl methacrylate; the foaming agent is a mixture of azodicarbonamide, sodium bicarbonate and calcium stearate, and the mass ratio of the azodicarbonamide, sodium bicarbonate and calcium stearate is 1:(0.5-0.8):(2-3).

2. The modified thermoplastic elastomer color-changing yoga mat material according to claim 1, characterized in that: The particle size of the nano zinc oxide is 50nm-100nm.

3. The modified thermoplastic elastomer color-changing yoga mat material according to claim 1, characterized in that: The molecular weight of the epoxy crosslinking agent is 7000-8000.

4. A method for preparing the modified thermoplastic elastomer color-changing yoga mat material according to any one of claims 1 to 3, characterized in that: The specific steps include: Thermoplastic polyester elastomer and styrene-butadiene block copolymer are mixed, and then a foaming agent, an epoxy cross-linking agent, an isocyanate cross-linking agent and a color-changing powder are added and kneaded to form a mixture. Finally, the mixture is open-milled, sheeted and foamed to obtain a modified thermoplastic elastomer color-changing yoga mat material.

5. The method for preparing the modified thermoplastic elastomer color-changing yoga mat material according to claim 4, characterized in that: The banburying temperature is 100-110°C, and the foaming temperature is 160-170°C.

Images