Supercritical PBAT foaming material, preparation method and sports protective helmet

Abstract

The invention discloses a supercritical PBAT foaming material, a preparation method and a sports ware helmet. The supercritical PBAT foaming material is prepared from the following raw materials in parts by weight: 50-75 parts of improved PBAT, 2-10 parts of PLA, 0.5-1.5 parts of a foaming agent and 0.5-2 parts of an auxiliary agent, each part of the improved PBAT is prepared from the following raw materials in parts by weight: 90 to 100 parts of adipic acid, 110 to 120 parts of terephthalic acid, 85 to 95 parts of 1, 4-butanediol, 40 to 45 parts of 2, 5-furandimethanol and 45 to 60 parts of N-(2, 3-dihydroxypropyl) maleimide; compared with the prior art, the supercritical foaming material is more environment-friendly, the secondary valence bond DA bond is introduced, and when the supercritical foaming material is impacted, the secondary valence bond can absorb energy to be split and recombined, so that the received impact energy is consumed, and the supercritical foaming material has the characteristics of non-Newtonian fluid and good damping and buffering capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of helmet cushioning, and in particular to a supercritical PBAT foaming material and a preparation method thereof, and a sports protective gear helmet. Background Art

[0002] The cushioning layer of a helmet is a key component to ensure cycling safety. The cushioning layer of helmets on the market is mainly made of expanded polystyrene (EPS), which has good energy absorption and tear resistance. When the helmet is impacted, the cushioning layer will be squeezed and deformed to absorb the impact force, thereby reducing the impact force on the head and protecting the head from injury. In addition, the foam inside the EPS cushioning layer will form a series of small holes, so that the impact force is dispersed throughout the cushioning layer, further reducing the direct impact on the head and reducing the degree of damage and injury to the head. This effect of dispersing the impact force helps to improve the protective performance of the helmet, reduce the rotation and swing of the head, and thus reduce the risk of injury to the brain and cervical spine during a collision.

[0003] However, the applicant found that traditional expanded polystyrene (EPS) absorbs impacts by breaking the material, which makes the helmet unable to withstand multiple impacts. Even ordinary low-energy bumps will affect the safety performance of the helmet in long-term use. Another supercritical expanded polypropylene (EPP) material commonly used in the helmet buffer layer can withstand multiple impacts, but it mainly relies on the elastic buffering principle similar to a spring to absorb the impact force. The buffering capacity is poor and a thicker thickness is required to pass the relevant helmet CE impact test, which affects comfort. At the same time, both materials are traditional plastics that cannot be biodegraded and will have long-term impacts on the environment.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a supercritical PBAT foam material and a preparation method thereof for a helmet buffer layer, and a sports protective gear helmet. In the supercritical PBAT foam material of the present invention, a secondary bond DA bond is introduced. When impacted, the secondary bond can absorb energy to split and reorganize the secondary bond, thereby consuming the received impact energy, so that the supercritical foam material has the characteristics of a non-Newtonian fluid and has better shock-absorbing and buffering capabilities.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0007] The first aspect of the present invention provides a supercritical PBAT foaming material, wherein the supercritical PBAT foaming material comprises the following raw materials in parts by weight:

[0008] 50-75 parts of modified PBAT, 2-10 parts of PLA, 0.5-1.5 parts of foaming agent and 0.5-2 parts of auxiliary agent;

[0009] Each portion of the modified PBAT is prepared from the following raw materials in parts by weight:

[0010] 90-100 parts of adipic acid, 110-120 parts of terephthalic acid, 85-95 parts of 1,4-butanediol, 40-45 parts of 2,5-furan dimethanol and 45-60 parts of N-(2,3-dihydroxypropyl)maleimide.

[0011] Preferably, the mass ratio of the 2,5-furan dimethanol to N-(2,3-dihydroxypropyl)maleimide is 1:(1.202-1.469).

[0012] Preferably, the mass ratio of the 2,5-furan dimethanol to N-(2,3-dihydroxypropyl)maleimide is 1:(1.335-1.469).

[0013] Preferably, the auxiliary agent includes a plasticizer and a coupling agent;

[0014] The mass ratio of the plasticizer to the coupling agent is 1:(0.5-1).

[0015] The second aspect of the present invention provides a method for preparing the supercritical PBAT foaming material, comprising the following steps:

[0016] (a) adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol are mixed and polycondensed, and after the polycondensation is completed, N-(2,3-dihydroxypropyl) maleimide is added to react to obtain a modified PBAT;

[0017] (b) blending the modified PBAT, PLA, a blowing agent and an auxiliary agent to obtain a mixed material;

[0018] (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product;

[0019] (d) extruding and drying the primary product to obtain a secondary sheet product;

[0020] (e) The secondary sheet product is subjected to carbon dioxide foaming treatment using 0.5-1.5 parts by weight of water in a molding foaming agent to obtain the supercritical PBAT foaming material.

[0021] Preferably, the step (a) comprises mixing adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol, adding p-toluenesulfonic acid and sulfurous acid, reacting at 160-180° C. for 45-60 min, then adding a catalyst and reacting at a temperature of 235-245° C. and a pressure of 40-50 Pa for 75-95 min; adding N-(2,3-dihydroxypropyl)maleimide and reacting at 55-65° C. for 105-115 min.

[0022] Preferably, in step (b), the blending time is 80 to 100 minutes.

[0023] Preferably, in step (e), the foaming treatment temperature is 110° C., the pressure is 20 MPa, and the time is 3 to 5 hours.

[0024] During preparation, the reaction temperature and time must be strictly controlled to reduce the occurrence of side reactions and improve the yield.

[0025] A third aspect of the present invention provides a sports protective gear helmet, wherein the buffer layer material of the sports protective gear helmet is the supercritical PBAT foaming material.

[0026] Compared with the prior art, the beneficial effects of the present invention include at least:

[0027] The present invention introduces secondary bonds DA bonds into the supercritical foaming material. When impacted, the secondary bonds can absorb energy to split and reorganize the secondary bonds, thereby consuming the received impact energy, so that the supercritical foaming material has the characteristics of a non-Newtonian fluid and has better shock-absorbing and buffering capabilities. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0029] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0030] The present application provides a supercritical PBAT foaming material, wherein the raw materials of the supercritical PETA foaming material include the following raw materials in parts by weight: 50-75 parts of modified PBAT, 2-10 parts of PLA, 0.5-1.5 parts of foaming agent and 0.5-2 parts of auxiliary agent. The modified PBAT designed in the present application and the PLA used in the present application are both biodegradable materials, free of pollution and residue, and the protective gear made of the supercritical PBAT foaming material in the present application has excellent shock absorption and buffering capabilities.

[0031] Example 1

[0032] This embodiment is a supercritical PBAT foaming material, and the supercritical PETA foaming material includes the following raw materials in parts by weight:

[0033] 65 parts of modified PBAT, 6 parts of PLA, 1 part of foaming agent and 1.5 parts of auxiliary agent;

[0034] Each portion of the modified PBAT is prepared from the following raw materials in parts by weight:

[0035] Adipic acid 95 parts, terephthalic acid 115 parts, 1,4-butanediol 90 parts, 2,5-furan dimethanol 42 parts and N-(2,3-dihydroxypropyl)maleimide 55 parts.

[0036] The auxiliary agent is a plasticizer and a coupling agent in a mass ratio of 1:0.5, the plasticizer is glycerol and acetylated tributyl citrate in equal volumes, and the coupling agent is a silane coupling agent.

[0037] The preparation method of the supercritical PBAT foaming material comprises the following steps:

[0038] (a) Adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol were mixed, p-toluenesulfonic acid and sulfurous acid were added, and the mixture was reacted at 160° C. for 60 min, and then a catalyst was added and the mixture was reacted at a temperature of 235° C. and a pressure of 50 Pa for 75 min; N-(2,3-dihydroxypropyl)maleimide was added and the mixture was reacted at 55° C. for 105 min to obtain a modified PBAT;

[0039] (b) blending the modified PBAT, PLA, a blowing agent and an auxiliary agent for 100 minutes to obtain a mixed material;

[0040] (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product;

[0041] (d) extruding and drying the primary product to obtain a secondary sheet product;

[0042] (e) placing the secondary sheet product into a compression foaming machine, foaming the secondary sheet product with carbon dioxide at a foaming temperature of 110° C., a pressure of 20 MPa, and a time of 3 h, and then cooling to 80° C. and normal pressure to obtain the supercritical PBAT foaming material.

[0043] Example 2

[0044] This embodiment is a supercritical PBAT foaming material, and the supercritical PETA foaming material includes the following raw materials in parts by weight:

[0045] 50 parts of modified PBAT, 2 parts of PLA, 0.5 parts of foaming agent and 1 part of auxiliary agent;

[0046] Each portion of the modified PBAT is prepared from the following raw materials in parts by weight:

[0047] Adipic acid 95 parts, terephthalic acid 115 parts, 1,4-butanediol 90 parts, 2,5-furan dimethanol 42 parts and N-(2,3-dihydroxypropyl)maleimide 55 parts.

[0048] The auxiliary agent is a plasticizer and a coupling agent in a mass ratio of 1:1, the plasticizer is glycerol and acetylated tributyl citrate in equal volumes, and the coupling agent is a silane coupling agent.

[0049] The preparation method of the supercritical PBAT foaming material comprises the following steps:

[0050] (a) Adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol were mixed, p-toluenesulfonic acid and sulfurous acid were added, and the mixture was reacted at 180° C. for 45 min, and then a catalyst was added and the mixture was reacted at a temperature of 245° C. and a pressure of 40 Pa for 95 min; N-(2,3-dihydroxypropyl)maleimide was added and the mixture was reacted at 65° C. for 115 min to obtain a modified PBAT;

[0051] (b) blending the modified PBAT, PLA, a blowing agent and an auxiliary agent for 100 minutes to obtain a mixed material;

[0052] (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product;

[0053] (d) extruding and drying the primary product to obtain a secondary sheet product;

[0054] (e) placing the secondary sheet product into a compression foaming machine, foaming the secondary sheet product with carbon dioxide at a foaming temperature of 110° C., a pressure of 20 MPa, and a time of 4 h, and then cooling to 80° C. and normal pressure to obtain the supercritical PBAT foaming material.

[0055] Example 3

[0056] This embodiment is a supercritical PBAT foaming material, and the supercritical PETA foaming material includes the following raw materials in parts by weight:

[0057] 75 parts of modified PBAT, 10 parts of PLA, 1.5 parts of foaming agent and 2 parts of auxiliary agent;

[0058] Each portion of the modified PBAT is prepared from the following raw materials in parts by weight:

[0059] Adipic acid 95 parts, terephthalic acid 115 parts, 1,4-butanediol 90 parts, 2,5-furan dimethanol 42 parts and N-(2,3-dihydroxypropyl)maleimide 55 parts.

[0060] The auxiliary agent is a plasticizer and a coupling agent in a mass ratio of 1:1, the plasticizer is glycerol and acetylated tributyl citrate in equal volumes, and the coupling agent is a silane coupling agent.

[0061] The preparation method of the supercritical PBAT foaming material comprises the following steps:

[0062] (a) Adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol were mixed, p-toluenesulfonic acid and sulfurous acid were added, and the mixture was reacted at 170° C. for 50 min, and then a catalyst was added and the mixture was reacted at a temperature of 240° C. and a pressure of 45 Pa for 80 min; N-(2,3-dihydroxypropyl)maleimide was added and the mixture was reacted at 60° C. for 110 min to obtain a modified PBAT;

[0063] (b) blending the modified PBAT, PLA, a blowing agent and an auxiliary agent for 100 minutes to obtain a mixed material;

[0064] (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product;

[0065] (d) extruding and drying the primary product to obtain a secondary sheet product;

[0066] (e) placing the secondary sheet product into a compression foaming machine, foaming the secondary sheet product with carbon dioxide at a foaming temperature of 110° C., a pressure of 20 MPa, and a time of 4 h, and then cooling to 80° C. and normal pressure to obtain the supercritical PBAT foaming material.

[0067] Comparative Example 1

[0068] This comparative example is a supercritical PBAT foaming material, and the supercritical PETA foaming material includes the following raw materials in parts by weight:

[0069] PBAT 65 parts, PLA 6 parts, foaming agent 1.5 parts and auxiliary agent 1.5 parts;

[0070] Each portion of PBAT is prepared from the following raw materials in parts by weight:

[0071] Adipic acid 95 parts, terephthalic acid 115 parts, 1,4-butanediol 90 parts, 2,5-furan dimethanol 42 parts.

[0072] The auxiliary agent is a plasticizer and a coupling agent in a mass ratio of 1:0.5, the plasticizer is glycerol and acetylated tributyl citrate in equal volumes, and the coupling agent is a silane coupling agent.

[0073] The preparation method of the supercritical PBAT foaming material comprises the following steps:

[0074] (a) Adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol are mixed, p-toluenesulfonic acid and sulfurous acid are added, and the mixture is reacted at 160° C. for 60 min, and then a catalyst is added and the mixture is reacted at a temperature of 235° C. and a pressure of 50 Pa for 75 min to obtain PBAT;

[0075] (b) blending PBAT, PLA, a blowing agent and an auxiliary agent for 100 minutes to obtain a mixed material;

[0076] (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product;

[0077] (d) extruding and drying the primary product to obtain a secondary sheet product;

[0078] (e) placing the secondary sheet product into a compression foaming machine, foaming the secondary sheet product with carbon dioxide at a foaming temperature of 110° C., a pressure of 20 MPa, and a time of 4 h, and then cooling to 80° C. and normal pressure to obtain the supercritical PBAT foaming material.

[0079] Comparative Example 2

[0080] This comparative example is a commercially available EPS helmet buffer layer protective gear material.

[0081] Comparative Example 3

[0082] This comparative example is a commercially available EPP helmet buffer layer protective gear material.

[0083] Experimental example

[0084] Performance Testing

[0085] The materials of Examples 1 to 3 and Comparative Examples 1 to 3 were respectively used to prepare helmet buffer layers of the same size, and performance tests were performed on the prepared helmet buffer layers.

[0086] Impact Cushioning: The helmet cushioning layer is impact tested using the reference standard ASTM F1045, and the measured data of each helmet cushioning layer and the minimum thickness and weight required to pass the test are recorded.

[0087] Test Results

[0088] The performance test results of the protective gear are shown in Table 1 below.

[0089] Table 1: Helmet cushioning layer performance test

[0090]

[0091] From Table 1, we can see that:

[0092] Compared with the comparative example, the helmet buffer layer protective gear material prepared in the embodiment of the present invention has better mechanical properties, and the helmet buffer layer protective gear material in the embodiment of the present invention is green, environmentally friendly and degradable.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A supercritical PBAT foam material used in a helmet buffer layer, characterized in that: The supercritical PETA foaming material comprises the following raw materials in parts by weight: 50-75 parts of modified PBAT, 2-10 parts of PLA, 0.5-1.5 parts of foaming agent and 0.5-2 parts of auxiliary agent; Each portion of the modified PBAT is prepared from the following raw materials in parts by weight: 90-100 parts of adipic acid, 110-120 parts of terephthalic acid, 85-95 parts of 1,4-butanediol, 40-45 parts of 2,5-furan dimethanol and 45-60 parts of N-(2,3-dihydroxypropyl)maleimide.

2. The supercritical PBAT foaming material according to claim 1, characterized in that: The mass ratio of the 2,5-furan dimethanol to N-(2,3-dihydroxypropyl)maleimide is 1:(1.202-1.469).

3. The supercritical PBAT foaming material according to claim 1, characterized in that: The mass ratio of the 2,5-furan dimethanol to N-(2,3-dihydroxypropyl)maleimide is 1:(1.335-1.469).

4. The supercritical PBAT foaming material according to claim 1, characterized in that: The auxiliary agents include plasticizers and coupling agents; The mass ratio of the plasticizer to the coupling agent is 1:(0.5-1).

5. The method for preparing the supercritical PBAT foaming material according to any one of claims 1 to 4, characterized in that: The steps include: (a) adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol are mixed and polycondensed, and after the polycondensation is completed, N-(2,3-dihydroxypropyl) maleimide is added to react to obtain a modified PBAT; (b) blending the modified PBAT, PLA, a blowing agent and an auxiliary agent to obtain a mixed material; (c) melting and plasticizing the mixed material, kneading and mixing, extruding, cooling, pelletizing, and drying to obtain a primary product; (d) extruding and drying the primary product to obtain a secondary sheet product; (e) The secondary sheet product is subjected to carbon dioxide foaming treatment using 0.5-1.5 parts by weight of water in a molding foaming agent to obtain the supercritical PBAT foaming material.

6. The preparation method according to claim 5, characterized in that: The step (a) comprises: Adipic acid, terephthalic acid, 1,4-butanediol and 2,5-furan dimethanol are mixed, p-toluenesulfonic acid and sulfurous acid are added, and the mixture is reacted at 160-180° C. for 45-60 minutes, and then a catalyst is added and the mixture is reacted at a temperature of 235-245° C. and a pressure of 40-50 Pa for 75-95 minutes; N-(2,3-dihydroxypropyl)maleimide is added and the mixture is reacted at 55-65° C. for 105-115 minutes.

7. The preparation method according to claim 5, characterized in that: In the step (b), the blending time is 80-100 minutes.

8. The preparation method according to claim 5, characterized in that: In the step (e), the foaming treatment temperature is 110° C., the pressure is 20 MPa, and the time is 3 to 5 hours.

9. A sports protective helmet, characterized in that: The buffer layer material of the sports protective gear helmet is the supercritical PBAT foam material according to claim 1 or 2.

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