Photochromic TPEE thermoplastic elastomer, preparation method and application

Abstract

The invention relates to the technical field of high polymer materials, particularly discloses a photochromic TPEE thermoplastic elastomer, and also discloses a preparation method and application thereof. The photochromic TPEE provided by the invention is prepared from the following raw materials: purified terephthalic acid, 1, 4-butanediol, a polyether soft segment and a photochromic small molecule, and the photochromic small molecule is Rh6G-2OH. According to the TPEE with the photochromic function, the material structure comprises rhodamine micromolecules, the micromolecules have a spirolactam structure, and based on the structure, the elastomer material provided by the invention has the photochromic function. After being illuminated by ultraviolet rays, the elastomer material can absorb ultraviolet ray energy to generate a light response behavior, so that the material is discolored.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a photochromic TPEE thermoplastic elastomer, as well as its preparation method and application. Background Technology

[0002] Photochromic materials, as the name suggests, are materials whose color changes after being exposed to light. In recent years, photochromic materials have gradually become a research hotspot. These materials can undergo reversible changes in color and intensity under the influence of external stimuli, and can be widely used in fields such as optical information storage, optical switches, and photochromic clothing.

[0003] Thermoplastic polyester elastomer (TPEE) is a block copolymer containing polyester hard segments and polyether soft segments. Due to the chemical properties of the soft segments, this material can be made into films with excellent waterproof and breathable properties. This invention aims to provide a photochromic TPEE thermoplastic elastomer by modifying TPEE, thereby expanding the application areas of TPEE and its films. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a photochromic TPEE thermoplastic elastomer.

[0005] Meanwhile, the present invention also provides a method for preparing and applying the photochromic TPEE thermoplastic elastomer.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a photochromic TPEE thermoplastic elastomer, the raw materials for preparation including: purified terephthalic acid, 1,4-butanediol, polyether soft segments and photochromic small molecules, wherein the photochromic small molecules are Rh6G-2OH, having the structure shown in Formula I: Formula I.

[0007] In one embodiment of the present invention, the raw materials purified terephthalic acid, 1,4-butanediol, polyether soft segment, and photochromic small molecule contain the following mass percentages: purified terephthalic acid 20-45%, 1,4-butanediol 30-55%, polyether soft segment 15-25%, and photochromic small molecule 5-15%.

[0008] In a preferred embodiment of the present invention, the raw materials purified terephthalic acid, 1,4-butanediol, polyether soft segment, and photochromic small molecule contain the following mass percentages: purified terephthalic acid 34-36%, 1,4-butanediol 33-35%, polyether soft segment 20-22%, and photochromic small molecule 8-12%.

[0009] As one embodiment of the present invention, the raw materials for preparation further include at least one of titanium-based catalysts, auxiliary catalysts, alkali metal catalysts, crosslinking agents, heat stabilizers, and antioxidants.

[0010] In a preferred embodiment of the present invention, the raw materials for preparation further include titanium-based catalysts, auxiliary catalysts, alkali metal catalysts, crosslinking agents, heat stabilizers, and antioxidants.

[0011] As one embodiment of the present invention, the polyether soft segment is selected from one or two of PEG400, PEG600, PEG1000, PEG2000, PEG4000, PTMEG1000, PTMEG1800, and PTMEG2000.

[0012] In one embodiment of the present invention, the titanium-based catalyst is selected from one or both of tetrabutyl titanate and tetraisopropyl titanate; the amount of the titanium-based catalyst added is 0.04-0.08% of the mass of the purified terephthalic acid. Specifically, the amount of the titanium-based catalyst added can be 0.04%, 0.05%, 0.06%, 0.07%, or 0.08% of the mass of the purified terephthalic acid, or any value between 0.04% and 0.08%.

[0013] In one embodiment of the present invention, the auxiliary catalyst is selected from one or more of tetraethyl orthosilicate, methyl orthosilicate, and propyl orthosilicate; the amount of the auxiliary catalyst added is 0.001-0.003% of the mass of the purified terephthalic acid. For example, specifically, the amount of the auxiliary catalyst added can be 0.001%, 0.0018%, 0.002%, or 0.003% of the mass of the purified terephthalic acid, or any value between 0.001% and 0.003%.

[0014] In one embodiment of the present invention, the alkali metal catalyst is selected from any one of zinc acetate, sodium acetate, and magnesium acetate; the amount of the alkali metal catalyst added is 0.001-0.003% of the mass of the purified terephthalic acid. For example, specifically, the amount of the alkali metal catalyst added can be 0.001%, 0.002%, or 0.003% of the mass of the purified terephthalic acid, or any value between 0.001% and 0.003%.

[0015] In one embodiment of the present invention, the crosslinking agent is selected from one or more of pentaerythritol, glycerol, and glycidyl methacrylate; the amount of the crosslinking agent added is 0.01-0.06% of the mass of the purified terephthalic acid. For example, specifically, the amount of the crosslinking agent added can be 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, or 0.06% of the mass of the purified terephthalic acid, or any value between 0.01% and 0.06%.

[0016] In one embodiment of the present invention, the heat stabilizer is selected from at least one of triphenyl phosphate, triethyl phosphate, and trimethyl phosphate; the amount of heat stabilizer added is 0.03-0.07% of the mass of purified terephthalic acid. Specifically, the amount of heat stabilizer added can be 0.03%, 0.04%, 0.05%, 0.06%, or 0.07% of the mass of purified terephthalic acid, or any value between 0.03% and 0.07%.

[0017] In one embodiment of the present invention, the antioxidant is selected from one or two of antioxidant 1010, antioxidant 1076, antioxidant 412s, and antioxidant 168; the amount of antioxidant added is 0.08-0.15% of the mass of purified terephthalic acid. Specifically, the amount of antioxidant added can be 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, or 0.15% of the mass of purified terephthalic acid, or any value between 0.08% and 0.15%.

[0018] This invention also provides a method for preparing the photochromic TPEE thermoplastic elastomer described herein, comprising the following steps: (1) Take purified terephthalic acid and 1,4-butanediol, put them into esterification vessel 1, add titanium catalyst and auxiliary catalyst to carry out esterification reaction, and obtain ester 1; (2) Take purified terephthalic acid and photochromic small molecules, put them into esterification vessel 2, add titanium catalyst and auxiliary catalyst to carry out esterification reaction, and obtain esterified product 2; (3) The esterified compound 1, the esterified compound 2, the polyether soft segment, the alkali metal catalyst, the crosslinking agent, the heat stabilizer, and the antioxidant are mixed and polymerized in a polycondensation reactor to obtain the photochromic TPEE thermoplastic elastomer.

[0019] As one embodiment of the present invention, in step (1), the reaction temperature of the esterification reaction is 220-240℃, the reaction pressure is 60-80KPa, and the reaction time is 2-3h; In step (2), the esterification reaction temperature is 220-240℃, the reaction pressure is 40-60KPa, and the reaction time is 3-4h; In step (3), the polymerization reaction temperature is 230-250℃, the reaction pressure is 1-5KPa, and the reaction time is 1-2h.

[0020] The present invention also provides an application of the photochromic TPEE thermoplastic elastomer described herein in the preparation of photochromic films.

[0021] The present invention further provides a photochromic film, which is obtained by using the photochromic TPEE thermoplastic elastomer described in the present invention, and the thickness of the photochromic film is 20-100 μm.

[0022] The photochromic film can be prepared by blow molding or casting, and the resulting photochromic film can be used as downstream photochromic protective material, UV protection material, etc.

[0023] This invention provides a photochromic thermoplastic elastomer (TPEE) containing rhodamine-like small molecules with a spironolactone structure. Based on this structure, the elastomer material provided by this invention exhibits photochromic properties. Upon exposure to ultraviolet light, the elastomer material absorbs ultraviolet energy and exhibits a photoresponsive behavior, causing the material to change color. Further preparation of thin film materials can be used for applications such as photochromic protective films and UV-protective materials. Detailed Implementation

[0024] The technical solution of the present invention will be described in detail below through specific embodiments. These embodiments are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention.

[0025] Unless otherwise specified, all raw materials used in the following examples and comparative examples are commercially available products.

[0026] The photochromic small molecule Rh6G-2OH used was obtained by referring to the method disclosed in patent application CN109320519A.

[0027] The polyether soft segment used is PTMEG1000.

[0028] The titanium-based catalyst used is tetrabutyl titanate.

[0029] The auxiliary catalyst used is tetraethyl orthosilicate.

[0030] The alkali metal catalyst used is zinc acetate.

[0031] The crosslinking agent used is pentaerythritol.

[0032] The heat stabilizer used is triphenyl phosphate.

[0033] The antioxidant used is antioxidant 412s.

[0034] The specific amounts of each raw material used in Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0035] Table 1 Note: " / " in the table indicates that it has not been added.

[0036] Example 1 This embodiment provides a photochromic TPEE thermoplastic elastomer. The raw materials are shown in Table 1, and the preparation method includes the following steps: (1) Take 2500g of purified terephthalic acid (PTA) and 5000g of 1,4-butanediol (BDO), put them into esterification vessel 1, add 1.5g of tetrabutyl titanate and 0.05g of tetraethyl orthosilicate, and carry out esterification reaction to obtain ester 1; the reaction temperature of esterification reaction is 220℃, the reaction pressure is 60KPa, and the reaction time is 2h; (2) Take 2500g of purified terephthalic acid (PTA) and 1000g of photochromic small molecule (Rh6G-2OH), put them into esterification vessel 2, add 1.5g of tetrabutyl titanate and 0.04g of tetraethyl orthosilicate, and carry out esterification reaction to obtain esterified product 2; the reaction temperature of the esterification reaction is 230℃, the reaction pressure is 40KPa, and the reaction time is 3h; (3) The obtained ester 1 and ester 2 are mixed with 3000g of polyether soft segment (PTMEG1000), 0.1g of zinc acetate, 2g of pentaerythritol, 2.5g of triphenyl phosphate and 6g of antioxidant 412s. The mixture is then subjected to polymerization in a polycondensation reactor. The distillation column is closed, the vacuum system is turned on, and the vacuum valve is slowly opened. The pressure inside the polycondensation reactor is reduced to 2KPa within 30 minutes, and the temperature inside the polycondensation reactor is raised to 250°C. The polymerization reaction is carried out for 1.5h, the reaction is stopped, and the material is discharged to obtain photochromic TPEE thermoplastic elastomer.

[0037] Example 2 This embodiment provides a photochromic TPEE thermoplastic elastomer. The raw materials are shown in Table 1, and the preparation method includes the following steps: (1) Take 3000g of purified terephthalic acid (PTA) and 5000g of 1,4-butanediol (BDO), put them into esterification vessel 1, add 1.5g of tetrabutyl titanate and 0.05g of tetraethyl orthosilicate, and carry out esterification reaction to obtain ester 1; the reaction temperature of the esterification reaction is 240℃, the reaction pressure is 80KPa, and the reaction time is 2h; (2) Take 2000g of purified terephthalic acid (PTA) and 1300g of photochromic small molecule (Rh6G-2OH), put them into esterification vessel 2, add 1.5g of tetrabutyl titanate and 0.04g of tetraethyl orthosilicate, and carry out esterification reaction to obtain esterified product 2; the reaction temperature of the esterification reaction is 240℃, the reaction pressure is 50KPa, and the reaction time is 3h; (3) The obtained ester 1 and ester 2 are mixed with 3000g of polyether soft segment (PTMEG1000), 0.1g of zinc acetate, 2g of pentaerythritol, 2.5g of triphenyl phosphate and 6g of antioxidant 412s. The mixture is then subjected to polymerization in a polycondensation reactor. The distillation column is closed, the vacuum system is turned on, and the vacuum valve is slowly opened. The pressure inside the polycondensation reactor is reduced to 3KPa within 30 minutes, and the temperature inside the polycondensation reactor is raised to 250°C. The polymerization reaction is carried out for 1.5h, the reaction is stopped, and the material is discharged to obtain photochromic TPEE thermoplastic elastomer.

[0038] Example 3 This embodiment provides a photochromic TPEE thermoplastic elastomer. The raw materials are shown in Table 1, and the preparation method includes the following steps: (1) Take 2500g of purified terephthalic acid (PTA) and 5000g of 1,4-butanediol (BDO), put them into esterification kettle 1, add 1.5g of tetrabutyl titanate and 0.05g of tetraethyl orthosilicate, and carry out esterification reaction to obtain ester 1; the reaction temperature of the esterification reaction is 235℃, the reaction pressure is 65KPa, and the reaction time is 2h; (2) Take 2500g of purified terephthalic acid (PTA) and 1500g of photochromic small molecule (Rh6G-2OH), put them into esterification vessel 2, add 1.5g of tetrabutyl titanate and 0.04g of tetraethyl orthosilicate, and carry out esterification reaction to obtain esterified product 2; the reaction temperature of the esterification reaction is 240℃, the reaction pressure is 55KPa, and the reaction time is 3h; (3) The esterified compound 1 and esterified compound 2 were mixed with 3000g of polyether soft segment (PTMEG1000), 0.1g of zinc acetate, 2g of pentaerythritol, 2.5g of triphenyl phosphate and 6g of antioxidant 412s. The mixture was then subjected to polymerization in a polycondensation reactor. The distillation column was closed, the vacuum system was turned on, and the vacuum valve was slowly opened. The pressure inside the polycondensation reactor was reduced to 4KPa within 30 minutes, and the temperature inside the polycondensation reactor was raised to 250°C. The polymerization reaction was carried out for 2 hours, the reaction was stopped, and the material was discharged to obtain photochromic TPEE thermoplastic elastomer.

[0039] Comparative Example 1 This comparative example provides a TPEE thermoplastic elastomer. The raw materials for preparation are shown in Table 1, and the preparation method includes the following steps: (1) Take 3500g of purified terephthalic acid (PTA) and 5000g of 1,4-butanediol (BDO), put them into esterification kettle 1, add 1.5g of tetrabutyl titanate and 0.05g of tetraethyl orthosilicate, and carry out esterification reaction to obtain ester 1; the reaction temperature of esterification reaction is 235℃, the reaction pressure is 65KPa, and the reaction time is 2h; (2) The esterified compound 1 obtained was mixed with 3000g of polyether soft segment (PTMEG1000), 0.1g of zinc acetate, 2g of pentaerythritol, 2.5g of triphenyl phosphate and 6g of antioxidant 412s. The mixture was then subjected to polymerization in a polycondensation reactor. The distillation column was closed, the vacuum system was turned on, and the vacuum valve was slowly opened. The pressure inside the polycondensation reactor was reduced to 2KPa within 30 minutes, and the temperature inside the polycondensation reactor was raised to 250°C. The polymerization reaction was carried out for 1 hour, the reaction was stopped, and the material was discharged to obtain TPEE thermoplastic elastomer.

[0040] The photochromic TPEE thermoplastic elastomers prepared in Examples 1-3 and Comparative Example 1 were used to prepare films with a thickness of 30 μm using a casting process.

[0041] The tensile strength and elongation at break of each of the films prepared above were tested.

[0042] Then, each film was irradiated with ultraviolet light, and it was observed whether the film changed color after ultraviolet irradiation. Subsequently, its tensile strength and elongation at break were tested.

[0043] The test results are shown in Table 2.

[0044] Table 2 Films made from the TPEE thermoplastic elastomers prepared in Examples 1-3 will change color after being irradiated with ultraviolet light. Furthermore, since the photochromic small molecules contain multiple rigid structures such as six-membered rings and five-membered rings, the films made from TPEE thermoplastic elastomers with added small molecules also have high tensile strength.

[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A photochromic TPEE thermoplastic elastomer, characterized in that, The raw materials for preparation include: purified terephthalic acid, 1,4-butanediol, polyether soft segments, and photochromic small molecules, wherein the photochromic small molecules are Rh6G-2OH, having the structure shown in Formula I: Formula I.

2. The photochromic TPEE thermoplastic elastomer according to claim 1, characterized in that, The purified terephthalic acid, 1,4-butanediol, polyether soft segment, and photochromic small molecule contain 20-45% purified terephthalic acid, 30-55% 1,4-butanediol, 15-25% polyether soft segment, and 5-15% photochromic small molecule by mass percentage.

3. The photochromic TPEE thermoplastic elastomer according to claim 1, characterized in that, The raw materials for preparation also include at least one of titanium-based catalysts, auxiliary catalysts, alkali metal catalysts, crosslinking agents, heat stabilizers, and antioxidants.

4. The photochromic TPEE thermoplastic elastomer according to any one of claims 1-3, characterized in that, The polyether soft segment is selected from one or two of PEG400, PEG600, PEG1000, PEG2000, PEG4000, PTMEG1000, PTMEG1800, and PTMEG2000.

5. The photochromic TPEE thermoplastic elastomer according to claim 4, characterized in that, The titanium-based catalyst is selected from one or both of tetrabutyl titanate and tetraisopropyl titanate, and the amount of the titanium-based catalyst added is 0.04-0.08% of the mass of the purified terephthalic acid; The auxiliary catalyst is selected from one or more of tetraethyl orthosilicate, methyl orthosilicate, and propyl orthosilicate, and the amount of the auxiliary catalyst added is 0.001-0.003% of the mass of the purified terephthalic acid; The alkali metal catalyst is selected from any one of zinc acetate, sodium acetate, and magnesium acetate, and the amount of the alkali metal catalyst added is 0.001-0.003% of the mass of the purified terephthalic acid.

6. The photochromic TPEE thermoplastic elastomer according to claim 4, characterized in that, The crosslinking agent is selected from one or more of pentaerythritol, glycerol, and glycidyl methacrylate, and the amount of the crosslinking agent added is 0.01-0.06% of the mass of the purified terephthalic acid; The heat stabilizer is selected from at least one of triphenyl phosphate, triethyl phosphate, and trimethyl phosphate, and the amount of heat stabilizer added is 0.03-0.07% of the mass of the purified terephthalic acid; The antioxidant is selected from one or two of antioxidant 1010, antioxidant 1076, antioxidant 412s, and antioxidant 168, and the amount of antioxidant added is 0.08-0.15% of the mass of purified terephthalic acid.

7. A method for preparing the photochromic TPEE thermoplastic elastomer according to any one of claims 1-6, characterized in that, Including the following steps: (1) Take purified terephthalic acid and 1,4-butanediol, put them into esterification vessel 1, add titanium catalyst and auxiliary catalyst to carry out esterification reaction, and obtain ester 1; (2) Take purified terephthalic acid and photochromic small molecules, put them into esterification vessel 2, add titanium catalyst and auxiliary catalyst to carry out esterification reaction, and obtain esterified product 2; (3) The esterified compound 1, the esterified compound 2, the polyether soft segment, the alkali metal catalyst, the crosslinking agent, the heat stabilizer, and the antioxidant are mixed and polymerized in a polycondensation reactor to obtain the photochromic TPEE thermoplastic elastomer.

8. The preparation method according to claim 7, characterized in that, In step (1), the esterification reaction temperature is 220-240℃, the reaction pressure is 60-80KPa, and the reaction time is 2-3h; In step (2), the esterification reaction temperature is 220-240℃, the reaction pressure is 40-60KPa, and the reaction time is 3-4h; In step (3), the polymerization reaction temperature is 230-250℃, the reaction pressure is 1-5KPa, and the reaction time is 1-2h.

9. The application of the photochromic TPEE thermoplastic elastomer according to any one of claims 1-6 in the preparation of photochromic films.

10. A photochromic thin film, characterized in that, The photochromic TPEE thermoplastic elastomer is obtained using any one of claims 1-6, wherein the thickness of the photochromic film is 20-100 μm.

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