Diaryl ethylene copolymer as well as preparation method and application thereof

Abstract

The invention discloses a diarylethene copolymer as well as a preparation method and application thereof, and belongs to the technical field of macromolecules. The diarylethene copolymer provided by the invention comprises a structural unit A and a structural unit B, the structural unit A is derived from a diarylethene monomer; the structural unit B is derived from methyl methacrylate; the chemical formula of the diarylethene monomer is as shown in the formula I in the specification. The diarylethene copolymer provided by the invention has good dispersion stability, anti-fatigue performance and optical performance, can still keep excellent photochromic performance after high-temperature processing, and has good aging resistance, multiple optical variable cycle times and high light transmittance; the method can be widely applied to preparation of long-service-life and high-transparency resin compositions and workpieces.

Description

Technical Field

[0001] This invention belongs to the field of polymer technology, and particularly relates to a diarylethylene copolymer, its preparation method, and its application. Background Technology

[0002] Photochromic materials have broad application prospects in fields such as smart dimming (e.g., photochromic glasses, smart windows), anti-counterfeiting labels, optical information storage, and sensors. However, current commercial applications are mainly based on photochromic small-molecule doped resin systems (e.g., spiroxazine / PMMA used in photochromic lenses), which have significant technical bottlenecks that severely limit wider applications. These bottlenecks are mainly manifested in the following ways: 1. Poor dispersion stability: Small molecules have poor compatibility with resins, are prone to migration and aggregation, leading to uneven local color change or failure of the material (e.g., "spots" appearing on photochromic glasses after long-term use); 2. Insufficient fatigue resistance: Small molecules are prone to photodegradation under long-term ultraviolet light irradiation, resulting in low cycle life and affecting product durability; 3. Deterioration of mechanical properties: High concentrations of small molecule doping reduce the transparency of the resin (e.g., the transmittance of PMMA decreases significantly when the spiroxazine content is >5wt%). Summary of the Invention

[0003] In order to overcome at least one of the problems existing in the prior art, one of the objectives of the present invention is to provide a diarylethylene copolymer, which incorporates chromophores into the polymer chain through covalent bonds, and has excellent dispersion stability and fatigue resistance, as well as adjustable optical properties and high light transmittance.

[0004] The second objective of this invention is to provide a method for preparing the above-mentioned diarylethylene copolymer.

[0005] A third objective of this invention is to provide a resin composition.

[0006] The fourth objective of this invention is to provide a method for preparing the above-mentioned resin composition.

[0007] The fifth objective of this invention is to provide an application of the above-mentioned diarylethene copolymer or the above-mentioned resin composition.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides a diarylethylene copolymer, the diarylethylene copolymer comprising structural unit A and structural unit B; structural unit A is derived from a diarylethylene monomer; structural unit B is derived from methyl methacrylate; the chemical formula of the diarylethylene monomer is shown in Formula I below: Formula I.

[0009] In the diarylethylethylene monomers of Formula I of this invention, the dithiophene ethylene chromophores are covalently linked to methyl methacrylate phenyl modification groups on both sides. These modification groups can rationally control the influence of orbital energy levels on properties such as absorption spectra, fluorescence spectra, and photo-switching quantum efficiency, and endow them with good polymerization reactivity. In the diarylethylethylene copolymers formed by copolymerizing these diarylethylethylene monomers with methyl methacrylate, the chromophores are fixed by chemical bonds, making phase separation less likely and preventing migration and aggregation. This results in good dispersion stability during industrial processing. Furthermore, the copolymer chains can disperse light energy, reducing photodegradation of the chromophores and improving cycle life. Simultaneously, due to the block modification structure of methyl methacrylate, the diarylethylethylene copolymers possess tunable optical properties, particularly excellent light transmittance. This invention is beneficial for the industrial development of more photofunctionalized resin materials.

[0010] In some embodiments of the present invention, the combination of structural unit A and structural unit B includes, but is not limited to: ...ABAABBAB...; ...ABABAB...; ...AAAABBBBAAAA...; the main chain is ...AAAAA..., and the branch chain is ...BBB....

[0011] In some embodiments of the present invention, the molar ratio of structural unit A and structural unit B is 1:(20~60); for example, it can be any value or a range between 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55 or 1:60.

[0012] In some embodiments of the present invention, the number-average molecular weight (M0) of the diarylethene copolymer is... n The number average molecular weight is 4000~12000 g / mol; for example, it can be any value or a range between 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol, 10000 g / mol, 11000 g / mol or 12000 g / mol; the number average molecular weight of diarylethylene copolymers can be determined by GPC gel permeation chromatography.

[0013] In some preferred embodiments of the present invention, the number-average molecular weight of the diarylethene copolymer is 5000-10000 g / mol; in some more preferred embodiments of the present invention, the number-average molecular weight of the diarylethene copolymer is 6000-9000 g / mol.

[0014] The molecular weight of diarylethylene copolymers affects their photochromic cycle count and transmittance. Higher molecular weights result in longer copolymer chains, which disperse more light energy, leading to a decrease in transmittance. Conversely, lower molecular weights result in lower polymerization degrees, shorter copolymer chains, and less dispersed light energy, while the chromophores absorb more light energy, increasing photodegradation and consequently reducing the photochromic cycle count. Therefore, controlling the number-average molecular weight of diarylethylene copolymers within the aforementioned range allows for a balance between fatigue resistance and transmittance, resulting in superior photochromic cycle count and transmittance.

[0015] In some embodiments of the present invention, the weight-average molecular weight (M) of the diarylethene copolymer is... w The weight-average molecular weight of diarylethylene copolymers is 9000~17000 g / mol; for example, it can be any value or a range between 9000 g / mol, 10000 g / mol, 11000 g / mol, 12000 g / mol, 13000 g / mol, 14000 g / mol, 15000 g / mol, 16000 g / mol or 17000 g / mol; the weight-average molecular weight can be determined by GPC gel permeation chromatography.

[0016] In some preferred embodiments of the present invention, the weight-average molecular weight of the diarylethene copolymer is 11,000 to 15,000 g / mol; in some more preferred embodiments of the present invention, the weight-average molecular weight of the diarylethene copolymer is 13,000 to 14,000 g / mol.

[0017] In some embodiments of the present invention, the peak molecular weight (M) of the diarylethylene copolymer is... p The value is 8000~16000 g / mol; for example, it can be any value or a range between 8000 g / mol, 9000 g / mol, 10000 g / mol, 11000 g / mol, 12000 g / mol, 13000 g / mol, 14000 g / mol, 15000 g / mol or 16000 g / mol; the peak molecular weight of the diarylethylene copolymer can be determined by GPC gel permeation chromatography.

[0018] In some preferred embodiments of the present invention, the peak molecular weight of the diarylethene copolymer is 10,000 to 14,000 g / mol; in some more preferred embodiments of the present invention, the peak molecular weight of the diarylethene copolymer is 11,000 to 13,000 g / mol.

[0019] By controlling the weight-average molecular weight or peak molecular weight of diarylethylene copolymers within the above range, their fatigue resistance and light transmittance can be more stably controlled, resulting in better light-changing cycle performance and light transmittance.

[0020] A second aspect of the present invention provides a method for preparing the diarylethylene copolymer described in the first aspect of the present invention, comprising the following steps: mixing diarylethylene monomers, methyl methacrylate, an initiator and a solvent to perform a copolymerization reaction to obtain the diarylethylene copolymer.

[0021] The preparation method provided by this invention is simple, involves few synthesis steps, uses low-cost raw materials, and is easy to industrialize.

[0022] In some embodiments of the present invention, the temperature of the copolymerization reaction is 50~100°C; for example, it can be any value of 50°C, 60°C, 70°C, 80°C, 90°C or 100°C or a range between any two; in some specific embodiments of the present invention, the temperature of the copolymerization reaction is 60~80°C.

[0023] In some embodiments of the present invention, the copolymerization reaction time is 1 to 5 hours; for example, it can be any value of 1 hour, 2 hours, 3 hours, 4 hours or 5 hours or a range between any two; in some specific embodiments of the present invention, the copolymerization reaction time is 2 to 3 hours.

[0024] In some embodiments of the present invention, the initiator includes azo initiators, peroxide initiators, or combinations thereof; specifically, azo initiators may include at least one selected from azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), or dimethyl azobisisobutyrate (AIBME); peroxide initiators may include at least one selected from benzoyl peroxide (BPO), dicumyl peroxide (DCP), or diisopropyl peroxide dicarbonate (IPP). In some specific embodiments of the present invention, the initiator is selected from azobisisobutyronitrile (AIBN).

[0025] In some embodiments of the present invention, the solvent includes at least one of tetrahydrofuran (THF), 1,4-dioxane, dimethyl sulfoxide (DMSO), or N,N-dimethylformamide (DMF); in some specific embodiments of the present invention, the solvent is selected from tetrahydrofuran (THF).

[0026] In some embodiments of the present invention, the molar ratio of the diarylethene monomer to the methyl methacrylate is 1:(20~60); for example, it can be any value or a range between 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55 or 1:60; in some specific embodiments of the present invention, the molar ratio of the diarylethene monomer to the methyl methacrylate is 1:(30~50).

[0027] In some embodiments of the present invention, the molar ratio of the diarylethene monomer to the initiator is 1:(0.3~2); for example, it can be any value or a range between 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.3, 1:1.5, 1:1.8 or 1:2; in some specific embodiments of the present invention, the molar ratio of the diarylethene monomer to the initiator is 1:(0.5~1.5).

[0028] In some embodiments of the present invention, the ratio of the diarylethene monomer to the solvent is 1 mmol: (50~200) mL; for example, it can be any value or a range between 1 mmol: 50 mL, 1 mmol: 80 mL, 1 mmol: 100 mL, 1 mmol: 150 mL or 1 mmol: 200 mL; in some specific embodiments of the present invention, the ratio of the diarylethene monomer to the solvent is 1 mmol: (80~150) mL.

[0029] In some embodiments of the present invention, the diarylethylene monomer is prepared by a method comprising the following steps: reacting a compound of formula II with p-halobenzyl alcohol to obtain a compound of formula III; reacting the compound of formula III with methacrylic acid to obtain the diarylethylene monomer; Formula II; Formula III; Wherein, X is selected from halogens.

[0030] In some embodiments of the present invention, X is selected from F, Cl, Br or I; in some specific embodiments of the present invention, X is selected from Cl.

[0031] In some embodiments of the present invention, the p-halobenzyl alcohol includes at least one of p-fluorobenzyl alcohol, p-chlorobenzyl alcohol, p-bromobenzyl alcohol, or p-iodobenzyl alcohol; in some specific embodiments of the present invention, the p-halobenzyl alcohol is selected from p-bromobenzyl alcohol.

[0032] In some embodiments of the present invention, the compound of formula II can be prepared with reference to X. Ma, et al., Dyes Pigments, 2017, 139, 118-128.

[0033] In some embodiments of the present invention, the molar ratio of the compound of formula II to the p-halobenzyl alcohol is 1:(2~5); in some embodiments of the present invention, the molar ratio of the compound of formula II to the p-halobenzyl alcohol is 1:(2.5~4).

[0034] In some embodiments of the present invention, the reaction of the compound of formula II with p-halobenzyl alcohol can be a transition metal-catalyzed coupling reaction; in some specific embodiments of the present invention, the reaction of the compound of formula II with p-halobenzyl alcohol includes the following steps: first, reacting the compound of formula II sequentially with an organolithium compound and a borate ester compound to generate a borate ester intermediate, and then reacting the borate ester intermediate with the p-halobenzyl alcohol under the action of a palladium catalyst and a basic compound to generate the compound of formula III; further, the organolithium compound can be n-butyllithium (n-BuLi); the borate ester compound can be tributyl borate (B(OBu)3); the palladium catalyst can be tetrakis(triphenylphosphine)palladium; and the basic compound can be potassium carbonate.

[0035] In some embodiments of the present invention, the molar ratio of the compound of formula III to the methacrylic acid is 1:(2~4); in some embodiments of the present invention, the molar ratio of the compound of formula II to the p-halobenzyl alcohol is 1:(2.2~3).

[0036] In some embodiments of the present invention, the reaction of the compound of formula III with methacrylic acid can be an esterification reaction; in some specific embodiments of the present invention, the reaction of the compound of formula III with methacrylic acid includes the following steps: the compound of formula III reacts with methacrylic acid under the action of a condensing agent and a catalyst to generate the diarylethylene monomer; further, the condensing agent can be 1-ethyl-3-(3-dimethylpropylamine)carbamodiimide hydrochloride (EDCI); the catalyst can be 4-dimethylaminopyridine (DMAP).

[0037] A third aspect of the present invention provides a resin composition comprising the following components in parts by weight: 88 to 100 parts of a matrix resin and 0.1 to 12 parts of the diarylethylene copolymer described in the first aspect of the present invention.

[0038] The diarylethylene copolymer provided by this invention has excellent dispersion stability and can be uniformly dispersed in the matrix resin, so that the formed resin composition has good aging resistance, fatigue resistance and light transmittance. It effectively solves the problems of poor dispersion stability, poor fatigue resistance and decreased transparency of photochromic dyes in industrial processing in the prior art, and promotes the industrial development of more photofunctionalized resin materials.

[0039] In this invention, the matrix resin is used as the main material of the resin composition, accounting for more than 85 wt% of the total mass of the resin composition; for example, it can be any value or a range between 85 wt%, 88 wt%, 90 wt%, 92 wt%, 95 wt%, 97 wt%, 99 wt%, or 99.9 wt%.

[0040] In some embodiments of the present invention, the diarylene ethylene copolymer accounts for 0.1 to 12 wt% of the total mass of the resin composition; for example, it can be any value or a range between any two of 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, 1 wt%, 3 wt%, 5 wt%, 7 wt%, 10 wt%, or 12 wt%; in some preferred embodiments of the present invention, the photochromic compound accounts for 0.3 to 9 wt% of the total mass of the resin composition; in some more preferred embodiments of the present invention, the photochromic compound accounts for 0.7 to 7 wt% of the total mass of the resin composition.

[0041] Since the diarylethylene copolymer and the matrix resin are two different phases with different refractive indices, a higher amount of diarylethylene copolymer can lead to a decrease in the transmittance of the resin composition. Therefore, by controlling the amount of diarylethylene copolymer added within the aforementioned range, the resulting resin composition can exhibit better dispersion stability, fatigue resistance, and optical properties. Furthermore, it has been found that the diarylethylene copolymer of this invention has a methyl methacrylate block-modified structure, which can regulate the optical properties of the copolymer, allowing it to maintain high transmittance even at higher addition levels. This overcomes the technical challenge of significantly reducing resin transparency due to high concentrations of small molecule doping in existing research.

[0042] In some preferred embodiments of the present invention, the resin composition comprises the following components in parts by weight: 90-99.5 parts of matrix resin and 0.5-10 parts of diarylethene copolymer.

[0043] By adjusting the amount of each component in the resin composition within the above range, the components can exert a better synergistic effect, and the resulting resin composition can have better dispersion stability, fatigue resistance and optical properties.

[0044] In some embodiments of the present invention, the relative viscosity of the matrix resin is 1.5 to 4; for example, it can be any value or a range between any two of 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.3, 2.5, 2.7, 3, 3.3, 3.5, 3.7, or 4; the relative viscosity of the matrix resin can be in accordance with GB / T The test results are obtained according to standard 1632.1-2024. The solvent used to dissolve the matrix resin can be selected according to the specific matrix resin. For example, the test solvent used for PA resin is 96±0.1wt% concentrated sulfuric acid, and the test solvent used for PMMA resin is chloroform. The concentration of the prepared test solution can be 0.01±0.001g / mL. The test temperature can be 25±0.05℃. Specifically, when the matrix resin is PA, the specific test procedure is as follows: dissolve the PA resin with 96±0.1wt% concentrated sulfuric acid to prepare a sample solution with a concentration of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer. When the matrix resin is PMMA, the specific test procedure is as follows: dissolve the PMMA resin with chloroform to prepare a sample solution with a concentration of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer.

[0045] In some preferred embodiments of the present invention, the relative viscosity of the matrix resin is 1.6 to 3.3; in some more preferred embodiments of the present invention, the relative viscosity of the matrix resin is 1.7 to 2.7.

[0046] By adjusting the relative viscosity of the matrix resin within the above range to give it more suitable fluidity, the diarylethylene copolymer is better compatible and dispersed therein, thereby giving the resulting resin composition better dispersion stability, fatigue resistance and optical properties.

[0047] In some embodiments of the present invention, the matrix resin includes polyamide (PA), polymethyl methacrylate (PMMA), or a combination thereof; in some specific embodiments of the present invention, the matrix resin is selected from polyamide (PA) or polymethyl methacrylate (PMMA); further, the polyamide (PA) is selected from polyamide 6 (PA6).

[0048] Because the copolymer chain structure of the diarylethylene copolymer has good compatibility with the aforementioned matrix resin, migration and aggregation of the diarylethylene copolymer during processing can be avoided. Therefore, there is no pigment spot precipitation in the resin composition of this invention, and the resin composition has a stable structure, long photochromic lifetime, and a high number of photochromic cycles. Furthermore, polyamide (PA) and polymethyl methacrylate (PMMA) have high processing temperatures, and using them as the main materials of the resin composition ensures its high-temperature resistance. Both of these resins have good compatibility with the diarylethylene copolymer, resulting in a high-temperature resistant resin composition with good dispersion stability. Polyamide (PA) has an even higher processing temperature, and the diarylethylene copolymer exhibits good dispersion stability, fatigue resistance, and optical properties in PA resin materials at high processing temperatures, effectively solving the problems of poor dispersion stability, poor fatigue resistance, and decreased transparency in traditional small-molecule doped resin systems.

[0049] A fourth aspect of the present invention provides a method for preparing the resin composition described in the third aspect of the present invention, comprising the following steps: melt-blending the components to obtain the resin composition.

[0050] In some embodiments of the present invention, the melt blending temperature is ≥220°C; in some embodiments of the present invention, the melt blending temperature is 220~300°C; for example, it can be any value or a range between any two of 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C or 300°C; in some preferred embodiments of the present invention, the melt blending temperature is 240~260°C.

[0051] Each component in the resin composition of this invention has good high-temperature stability, effectively broadening its processing temperature range and promoting the industrial development of more photofunctionalized resin materials.

[0052] A fifth aspect of the present invention provides an article comprising a diarylethylene copolymer as described in the first aspect of the present invention, or a resin composition as described in the third aspect of the present invention.

[0053] The diarylethylene copolymer and resin composition of the present invention has good dispersion stability, fatigue resistance and optical properties, which effectively expands its application field and makes it suitable for the preparation of various high-performance parts.

[0054] In some embodiments of the present invention, the component is a photochromic component. A photochromic component refers to a component that has a photochromic effect.

[0055] Furthermore, the aforementioned components can be used in the fields of smart displays, optical sensing, anti-counterfeiting technology, or smart color-changing; even further, in the field of smart displays, applications can be in organic light-emitting diode (OLED) materials, quantum dot materials, substrates, and encapsulation materials; in the field of optical sensing, applications can be in photodiodes, optical fiber materials, infrared detection materials, and thermal imaging materials; in the field of anti-counterfeiting technology, applications can be in UV ink printing and anti-counterfeiting labels; and in the field of smart color-changing, applications can be in photochromic lenses, photochromic textile fibers, and smart building windows.

[0056] The beneficial effects of the present invention are: the diarylethylene copolymer provided by the present invention has good dispersion stability, fatigue resistance and optical properties, and can still maintain excellent photochromic properties after high temperature processing. It has good aging resistance, a high number of photochromic cycles and high light transmittance, and has wide applications in the preparation of long-life and highly transparent resin compositions and parts. Detailed Implementation

[0057] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0058] (1) The reagents used in the various embodiments and comparative examples of the present invention are described below: PA-1: Relative viscosity η=2.1 (Test standard is GB / T 1632.1-2024. The specific test procedure is as follows: Dissolve PA resin in 96±0.1wt% concentrated sulfuric acid to prepare a sample solution of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer). Model is PA6 T900, and the manufacturer is Huachuang Special Plastics New Material Technology Co., Ltd. PA-2: Relative viscosity η=2.8 (Test standard is GB / T 1632.1-2024. The specific test procedure is as follows: Dissolve PA resin with 96±0.1wt% concentrated sulfuric acid to prepare a sample solution of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer). The model is PA6 M2800, and the manufacturer is Guangdong Xinhui Meida Nylon Co., Ltd. PA-3: Relative viscosity η=3.4 (Test standard is GB / T 1632.1-2024. The specific test procedure is as follows: Dissolve PA resin with 96±0.1wt% concentrated sulfuric acid to prepare a sample solution of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer). Model is PA6 M3400, and the manufacturer is Guangdong Xinhui Meida Nylon Co., Ltd. PMMA: Relative viscosity η=1.8 (Test standard is GB / T 1632.1-2024, the specific test procedure is: dissolve PMMA resin in chloroform to prepare a sample solution of 0.01±0.001g / mL, and then measure the viscosity of the sample solution at 25±0.05℃ using an Ubbelohde viscometer), model is PMMA LG2, manufacturer is Sumitomo Chemical Singapore Pte. Ltd.; DAE monomer: 1,2-Di(2-methyl-5-chloro-3-thienyl)cyclopentene: It was prepared according to the reference (X. Ma, et al., Dyes Pigments, 2017, 139, 118-128).

[0059] (2) The preparation processes of the resin compositions in the various embodiments and comparative examples of the present invention are as follows: Weigh each component according to the formula, and use a Haitian MA160 injection molding machine for melt blending. Inject the mixture into 10 molds of thick square plates with dimensions of 90×55×2mm, which are the resin compositions. When the resin is PA, a four-stage melt blending temperature of 250℃ is used; when the resin is PMMA, a four-stage melt blending temperature of 220℃ is used.

[0060] (3) The resin compositions provided in the various embodiments and comparative examples of the present invention were used as samples, and their performance was determined according to the following test methods: Dual 85 performance test: Refer to GB / T 2423.50-2012 standard environmental test part 2, aging time 500 hours, the sample is a conventional 90×55×2mm thick square plate; observe and record the average number of pigment spots per square centimeter on the sample surface after aging. Optical variation cycle performance test: In a light-proof black box, the sample is irradiated with a 365nm monochromatic light source (handheld UV lamp, power: 6W). The sample is a conventional 90×55×2mm thick square plate. Irradiation for 1 minute followed by light-proofing for 2 minutes constitutes one cycle. The cycle continues until the sample does not respond to UV light. The number of cycles is recorded, which is the optical variation cycle number. Transmittance test: The transmittance of the sample was tested using a HAM-300 high-precision spectrophotometer (Hangzhou Yuanfang Optoelectronic Information Co., Ltd.); the sample was a standard 90×55×2mm thick square plate.

[0061] (4) The room temperature mentioned in the various embodiments and comparative examples of the present invention is 25±5℃.

[0062] Copolymer Example 1 A diarylethylene copolymer, designated Poly-DAE-MMA-1, has its number-average molecular weight M determined by GPC gel permeation chromatography. n It is 8155 g / mol, and the weight-average molecular weight M w It is 13546 g / mol, with a peak molecular weight M. p It is 12190 g / mol; The synthetic route for Poly-DAE-MMA-1 is as follows:

[0063] The specific synthesis steps are as follows: 1) Under conditions of light protection, anhydrous and oxygen-free environment, and nitrogen protection, 1,2-bis(2-methyl-5-chloro-3-thienyl)cyclopentene (compound 1, prepared according to reference X. Ma, et al., Dyes Pigments, 2017, 139, 118-128) (1.5 g, 4.57 mmol) and ultra-dry tetrahydrofuran (THF, 12 mL) were added to a 50 mL Shrek tube. After stirring to dissolve, the mixture was transferred to a cryogenic reactor (-78 °C). Subsequently, 2.5 M [amount of cyclopentene] was slowly added dropwise. n A hexane solution of -BuLi (5.5 mL, 13.7 mmol) was reacted for 1.5 hours. Then, deoxygenated B(OBu)3 (3.16 mL, 11.7 mmol) was rapidly added, and the reaction continued for another hour. The apparatus was then transferred to room temperature and stirred for 3-4 hours to obtain a yellow solution. After the reaction was complete, 5 mL of THF and 5 mL of H2O, 2 g of potassium carbonate, 0.1 g of tetraphenylphosphine palladium (0.0865 mmol), and 2.8 g of p-bromobenzyl alcohol (15 mmol) were added sequentially to the above reaction system. The mixture was heated to 80 °C and refluxed for 12 hours to complete the reaction. The reaction solution was cooled to room temperature and quenched with water, then extracted three times with ethyl acetate. The organic phases were combined, the organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was purified by rotary evaporation to remove the solvent. The crude product was separated by silica gel column chromatography with petroleum ether:ethyl acetate = 4:1 (v / v) as the eluent, yielding product DAE-OH, 1.8 g, yield 83%. 2) In a dry 100 mL flask, add DAE-OH (0.94 g, 2.0 mmol), methacrylic acid (0.41 g, 4.8 mmol), and 4-dimethylaminopyridine (DMAP) (0.24 g, 2.0 mmol), then add 40 mL of ultra-dry dichloromethane as solvent, and place the reaction system in an ice bath. After stirring for 30 minutes, add 1-ethyl-3-(3-dimethylpropylamine)carbamodiimide hydrochloride (EDCI) (0.76 g, 4.0 mmol). Continue stirring for 20 minutes, then remove the ice bath, and stir the reaction system overnight at room temperature. After the reaction is complete, wash the mixture three times with dichloromethane and water, dry it with anhydrous Na2SO4, and finally remove the solvent by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether:ethyl acetate = 12:1 as eluent to obtain a pale yellow transparent viscous liquid, namely DAE-MMA, 0.8 g, with a yield of 66%. 1 H NMR (400 MHz, Chloroform- d ) = 7.50 (s, 4H), 7.24(s, 4H), 6.98 (s, 2H), 6.97 (s, 1H), 6.78 (d, J = 5.2 Hz, 1H), 6.62 (s, 2H), 5.14 (s, 4H), 2.74 (t, J = 7.4 Hz, 4H), 2.04 (d, J = 4.8 Hz, 2H), 2.00 (s, 6H), 1.93 (s, 6H). 13 C NMR (151 MHz, Chloroform- d ) = 167.10, 136.09, 131.72, 129.75,128.71, 126.83, 126.06, 125.88, 125.42, 125.37, 122.20, 38.44, 38.37, 22.93,18.34, 14.44, 14.18. [M]+ calcd. for C 37 H 35 O4S2 + , 607.1976; found, 607.1909. 3) Ensure the system is kept in a light-proof, anhydrous, oxygen-free, and nitrogen-protected environment. Add DAE-MMA (0.608 g, 1.0 mmol), methyl methacrylate (3.9 g, 39 mmol), and azobisisobutyronitrile (AIBN) (0.13 g, 0.8 mmol) to a dry 250 mL flask. Add 100 mL of ultra-dry tetrahydrofuran as a solvent. Stir for 10 minutes, then heat to 70 °C and stir rapidly for 2-3 hours. After the reaction is complete, remove the solvent by rotary evaporation. Slowly add methanol dropwise, producing a white solid. After standing and separating the layers, filter to obtain the final product, Poly-DAE-MMA-1.

[0064] Copolymer Example 2 A diarylethylene copolymer, designated Poly-DAE-MMA-2, has its number-average molecular weight M determined by GPC gel permeation chromatography. n It is 5000 g / mol; The difference between the synthesis steps and those of copolymer Example 1 is that the amount of methyl methacrylate in step 3) is adjusted to 2g and the amount of azobisisobutyronitrile (AIBN) initiator is adjusted to 0.06g, while other conditions are the same as those of copolymer Example 1.

[0065] Copolymer Example 3 A diarylethylene copolymer, designated Poly-DAE-MMA-3, has its number-average molecular weight M determined by GPC gel permeation chromatography. n It is 10000 g / mol; The difference between the synthesis steps and those of copolymer Example 1 is that the amount of methyl methacrylate in step 3) is adjusted to 6g and the amount of azobisisobutyronitrile (AIBN) initiator is adjusted to 0.2g, and the stirring time after heating to 70°C is adjusted to 4-5h; other conditions are the same as those of copolymer Example 1.

[0066] Copolymer Comparative Example 1 A diarylethylene copolymer, designated Poly-DAE-MMA-4, has its number-average molecular weight M determined by GPC gel permeation chromatography. n It is 6014 g / mol; The synthetic route for Poly-DAE-MMA-4 is as follows:

[0067] The synthesis steps differ from those of copolymer Example 1 in that, in this example, compound 1 in step 1) is replaced with an equimolar amount of compound 1', while the other conditions are the same as those of copolymer Example 1.

[0068] The diarylene ethylene copolymers prepared by the copolymer examples and copolymer comparative examples described above were used to prepare the resin compositions described below.

[0069] Composition Examples 1-10 and Comparative Examples 1-2 Examples 1-10 and Comparative Examples 1-2 provide a series of resin compositions, the formulations of which are shown in Tables 1 and 2. The properties of the resin compositions of each example and comparative example were determined according to the test methods mentioned above, and the performance test results are also shown in Tables 1 and 2.

[0070] Table 1. Formulations (parts by mass) and performance test results of compositions in Examples 1-10

[0071] Table 2. Formulations (parts by mass) and performance test results of comparative examples 1-2.

[0072] As shown in Tables 1 and 2, no pigment spots were found in any of the compositions in Examples 1-10, and the number of light-changing cycles was all within 10. 4 With a transmittance of over 86.74%, the product exhibits excellent aging resistance, optical cycle life, and light transmittance. This is attributed to the good dispersion stability, fatigue resistance, and optical properties of the diarylethylene copolymer in each embodiment, as well as its good compatibility with the matrix resin.

[0073] In Examples 1-5, by rationally setting the ratio of the matrix resin to the diarylethylene copolymer, no pigment spots were found in the materials, and the number of photochromic cycles was all within 10. 5 The light transmittance is above 89.22%; the molecular weight of the diarylethylene copolymer in Examples 6-7 is controlled within a reasonable range, and the materials are free of color powder spots and have a light-changing cycle count of over 10. 4 The light transmittance is above 88.74% for each of the above-mentioned grades.

[0074] Composition Example 8 uses PMMA as the matrix resin, which has a relatively low processing temperature (220°C), resulting in a resin composition with better light transmittance. In contrast, using PA as the matrix resin can achieve a higher processing temperature (250°C), while also ensuring good aging resistance, photo-changing cycle life, and light transmittance. The resin composition provided by this invention has a wide processing temperature range, which is beneficial for the industrial development of more photofunctionalized resin materials.

[0075] In Examples 9-10, the relative viscosity of the matrix resin is controlled within a reasonable range to ensure good fluidity, which is beneficial for achieving good compatibility and dispersion of the diarylethylene copolymer. Furthermore, the screw shear strength required during the melt blending process of the raw materials is kept low to reduce the risk of failure. This ensures that the final resin composition has good aging resistance and photochromic cycle life, while also having high light transmittance.

[0076] The composition used in Comparative Example 1 is an unpolymerized small molecule monomer, 1,2-di(5-methylthiophene)cyclopentene. This monomer has poor dispersibility in the matrix resin, is prone to migration and aggregation, leading to uneven local discoloration and numerous pigment spots. Furthermore, this small molecule monomer is susceptible to photodegradation under long-term ultraviolet light irradiation, resulting in a short photochromic cycle life (<10 cycles). 3 The product has poor durability; at the same time, adding a high concentration of small molecules will reduce the transparency of the material. In Comparative Example 1, the light transmittance is only 88.61% with a monomer addition of 5 wt%, while in Example 4, the light transmittance is 90.36% with the same addition amount.

[0077] The diarylethylene copolymer in Comparative Example 2 was only modified by unilateral grafting, resulting in a greater degree of photodegradation of the chromophore during the light exposure process, leading to fewer photo-changing cycles and a shorter photo-changing cycle life.

[0078] In summary, the diarylethylene copolymer provided by this invention has good dispersion stability, fatigue resistance and optical properties. It can still maintain excellent photochromic properties after high-temperature processing. It has good aging resistance, a high number of photochromic cycles and high light transmittance. It has wide applications in the preparation of long-life and highly transparent resin compositions and parts.

Claims

1. A diarylethylene copolymer, characterized in that, The diarylethylene copolymer comprises structural unit A and structural unit B; structural unit A is derived from diarylethylene monomers; structural unit B is derived from methyl methacrylate; the chemical formula of the diarylethylene monomers is shown in Formula I below: Formula I.

2. The diarylethylene copolymer according to claim 1, characterized in that, The number-average molecular weight of the diarylethylene copolymer is 4000~12000 g / mol; And / or, the weight-average molecular weight of the diarylethylene copolymer is 9000~17000 g / mol; And / or, the peak molecular weight of the diarylethylene copolymer is 8000~16000 g / mol.

3. A method for preparing the diarylethylene copolymer as described in claim 1 or 2, characterized in that, Includes the following steps: The diarylethylene copolymer is obtained by copolymerizing diarylethylene monomers, methyl methacrylate, initiator and solvent.

4. The preparation method according to claim 3, characterized in that, The copolymerization reaction is carried out at a temperature of 50~100℃; And / or, the copolymerization reaction takes 1 to 5 hours.

5. A resin composition, characterized in that, The components include the following parts by weight: 88-100 parts of matrix resin and 0.1-12 parts of the diarylethylene copolymer as described in claim 1 or 2.

6. The resin composition according to claim 5, characterized in that, The relative viscosity of the matrix resin is 1.5~4.

7. The resin composition according to claim 5, characterized in that, The matrix resin includes polyamide, polymethyl methacrylate, or a combination thereof.

8. A method for preparing a resin composition according to any one of claims 5 to 7, characterized in that, Includes the following steps: The components are melt-blended to obtain the resin composition.

9. The preparation method according to claim 8, characterized in that, The temperature of the melt blend is ≥220℃.

10. A component, characterized in that, The component comprises the diarylethylene copolymer as described in claim 1 or 2, or the resin composition as described in any one of claims 5 to 7.

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