RU2415157C1 - Copolymers of n-vinylcarbazole with n-vinylcaprolactam and solid solutions of polymethyl methacrylate containing terbium ions and such copolymers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry and physics-chemistry of polymers, specifically to novel copolymers of N-vinylcarbazole and N-vinylcaprolactam. The invention also relates to solid solutions of polymethyl methacrylate which contain Tb³⁺ ions and said copolymers. Described are copolymers of N-vinylcarbazole with N-vinylcaprolactam and solid solutions of polymethyl methacrylate containing Tb³⁺ ions and copolymers of N-vinylcarbazole with N-vinylcaprolactam.

EFFECT: obtaining metal-polymer solid solutions in polymethyl methacrylate based on copolymers of N-vinylcarbazole with N-vinylcaprolactam of the disclosed composition, characterised by high luminescence intensity between 344 and 700 arbitrary units, and the obtained copolymer solid solutions can be of interest in the design of laser, luminescent, electroluminescent ad high-speed switching devices.

2 cl, 8 ex, 1 tbl, 3 dwg

Description

The invention relates to the chemistry and physical chemistry of polymers, namely to the first-obtained copolymers of N-vinylcarbazole and N-vinylcaprolactam. The invention also relates to solid solutions of polymethylmethacrylate, including Tb ³⁺ ions and the above copolymers.

It is known that rare-earth element ions (REE) form metal-polymer complexes (MPC) with polymers of a certain chemical structure. Some of them, for example, MPCs with Tb ³⁺ ions, exhibit luminescence in a solution and a block, characterized by a narrow luminescence band and its high stability (for example, Tb ³⁺ MPC has a green glow with a maximum at 543 nm).

Such IPCs find practical application in the development of laser, luminescent, electroluminescent, high-speed switching devices. (1. Lanthanide Probes in Life, Chemical and Earth Sciences. Theory and Practice / Ed. By Bunzli J.-CG, Choppin GR Amsterdam: Elsevier, 1989; 2. Okamoto S., Vyprachticky D., Furuya H., Abe F ., Okamoto Y. // Macromolecules. 1996. V. 29. No. 10. P. 3511; 3. Crescenzi V., Brittain HG, Yoshino N., Okamoto Y. // J. Polym. Sci., Polym. Phys . Td. 1985. V. 23. P. 437; 4. Klink SI, Hebbink GA et al. Sensitized near-infrared luminescence from polydentate triphenylene-functionalized Nd ³⁺ , Yb ³⁺ and Er ³⁺ complexes // Journal of Appl Phys. 1981. V. 86. P. 1181-1185.)

Claimed copolymers based on N-vinylcarbazole (VK) with N-vinylcaprolactam (ON) of the general formula:

where m: n = (7-21) :( 93-79) mol. %, [η] = (0.13-0.16) dl / g.

Solid solutions of these copolymers with terbium ions (Tb ³⁺ ) in the polymer matrix of polymethyl methacrylate are also an invention. In such copolymers, the ratio of the units of N-vinylcarbazole and N-vinylcaprolactam (7-21): (93-79) mol. %, intrinsic viscosity [η] = (0.13-0.16) dl / g, molar ratio [Tb ³⁺ ]: [VK] = 0.8-1.1; the content of VK units in the solid solution in the polymer matrix is 0.7-0.9 wt. %

A large number of publications have been devoted to the preparation of Tb ³⁺ complexes with polymer ligands of various chemical structures and the study of their photophysical and electroluminescent properties. Polymers containing various functional groups capable of forming coordination or donor-acceptor bonds with REE ions are used as polymer ligands for producing known MPCs with Tb ³⁺ ions (1. Rosendo A., Flores M., Cordoba G. et al. / Synthesis, characterization and luminescence properties of Tb ³⁺ and Eu ³⁺ - doped poly (acrylic) acid // Material Setters. 2003. V. 57. P. 2885-2893; 2. Anufrieva E.V., Nekrasova T. N., Ananyeva T.D., Gromova R.A., Lushchik V.B., Krakovyak MG / Structural organization of macromolecules and luminescence of terbium ions in macromolecular metal complexes.// High molecular compound Ser. A. 2000.V. 42. No. 6. S.994-1001; 3. Chenxia D., Lin M., Yan X. et al. / Synthesis and photophysical characterization of terbium - polymer complexes containing salicylate ligand // European Polymer J. 1998. V. 34. No. 1. P. 23-29; 4. Karasev V.A., Petrochenkova N.V. / Lanthanide-containing polymers // Vladivostok: Dalnauka, 2005. 194 p.).

Known copolymers of N-vinylcarbazole and trialkoxyvinylsilane or triacetoxyvinylsilane, N-vinylcarbazole and monomers from the group consisting of lower alkyl (meth) acrylates and styrene (5. US patent No. 4,039,463, filed April 16, 1975, published August 2, 1977. ) Such copolymers are used in electrostatography as a developer in a mixture with iron-containing metal powders.

Composite materials are also described containing copolymers of N-vinylcarbazole with styrene, (meth) acrylonitrile, and ethylene derivatives (6. US Patent No. 4,005,059, filed April 30, 1974, published January 25, 1977). Such copolymers have good thermal characteristics and adhesive properties and can be used as protective coatings on metals and to create metal-plastic laminates.

The copolymers of N-vinylcarbazole and N-vinylphthalimide or its isostructural modifications are photoconductive materials; they are proposed to be used in electrophotography (7. US patent No. 3 970 602, filed October 23, 1974, published July 20, 1976).

The use of N-vinylcarbazole in an amount of 1-30% as one of the components of a thermoplastic polymer material is described (8. US patent No. 5,266,638, filed November 13, 1992, published November 30, 1993).

The copolymers of N-vinylcarbazole and coumarin derivatives were used to create electroluminescent layers (9. US Patent No. 5,587,444, filed December 27, 1994, published December 24, 1996).

The known solutions do not describe the formation of metal-polymer complexes with the ability to such a level of luminescence, which can provide practical use of the material.

It is also known that in the published solutions, the preparation of luminescent polymer systems is associated with the formation of complexes based on coordination or donor-acceptor interactions, which are also realized with low molecular weight ligands. However, the modification of polymers of various chemical structures, which do not contain complexing groups, by rare-earth metal ions can significantly expand their functionality and give new properties.

For example, it was proposed to use homopoly (N-vinylcarbazole), in which the low molecular weight luminescent complex of europium is dispersed, as a medium that maintains a sufficiently high level of red radiation and has electroluminescent properties (9. J. Peng, N. Takada, N. Minami / Red electroluminescence of europium complex dispersed in poly (N-vinylcarbazole) // Thin Solid Films, 405 (2002) P. 224-227).

The objective of the invention is the creation of effectively luminescent solid metal-polymer solutions.

This problem was solved, firstly, by copolymers based on N-vinylcarbazole with N-vinylcaprolactam of the general formula:

where m: n = (7-21) :( 93-79) mol. %, [η] = (0.13-0.16) dl / g.

The problem was also solved by solid solutions of these copolymers with terbium ions (Tb ³⁺ ) in the polymer matrix of polymethylmethacrylate, the ratio of the units of N-vinylcarbazole (VK) and N-vinylcaprolactam (ON) in such copolymers (7-21) :( 93-79) pier %, intrinsic viscosity [η] = (0.13-0.16) dl / g, molar ratio [Tb ³⁺ ]: [VK] = 0.8-1.1, the content of VK units in the solid solution is 0, 7-0.9 wt.%.

The copolymers of vinylcarbazole with vinylcaprolactam (VK-ON) were synthesized for the first time. They are obtained by free radical copolymerization in solution with a variable content of monomers in the initial mixture. As the initiator use dinitrile azoisobutyric acid, the solvent is dimethylacetamide. The polymerization is carried out in sealed ampoules in an argon atmosphere at 60 ° C for 48-72 hours. Target copolymers (VK-ON) are isolated from the solution by precipitation into diethyl ether, reprecipitated from dimethylformamide into ether, dried in vacuum at room temperature to constant weight.

The composition of the obtained copolymers is determined by UV spectroscopy, the molecular weights of the copolymers are evaluated by the method of viscometry.

Based on copolymers with the declared content of VK units (7-21) mol. %, [η] = (0.13-0.16) dl / g and Tb ³⁺ ions their solid solutions in polymethyl methacrylate are obtained. As polymethyl methacrylate, polymers with a relatively low molecular weight are used, which allows them to easily dissolve in dimethylformamide, from the solutions of which it is quite easy to quantitatively remove the solvent.

To obtain a solid solution of the claimed copolymers (VK-ON) with Tb ³⁺ ions in polymethyl methacrylate, a solution in dimethylformamide, which contains the claimed copolymer, Tb ³⁺ ions and polymethyl methacrylate, is preliminarily prepared. Films are cast from the resulting solution onto a glass substrate, which are dried at a temperature of 60 ° C to constant weight. The thickness of the films for luminescent studies is 5-10 microns. The luminescence intensity of the obtained solid solutions (films) is measured on an LS-100 luminescent spectrophotometer (PTI, Canada) using an attachment for measuring the luminescence intensity of solid samples. The resulting film has intense green luminescence excited by light at a wavelength of 300 nm, with a maximum luminosity at a wavelength of 543 nm (Fig. 1, curves 1, 2).

It was previously established that in dimethylformamide the claimed copolymers with Tb ³⁺ ions only detect intrinsic luminescence of VK units (FIG. 2). In the polymethylmethacrylate matrix, the claimed copolymers without Tb ³⁺ ions also show only intrinsic luminescence of VK units, and Tb ³⁺ ions without a copolymer show a low level of luminescence (Fig. 1, curves 3, 4). The use of polystyrene or poly-N-vinylpyrrolidone as a matrix gives significantly lower luminescence intensities (Fig. 3).

The claimed content of VK units in the copolymer (7-21) mol. % The declared values are best confirmed by a decrease in the effect by 1-2 orders of magnitude when the content of VK units in the copolymer is higher and lower than the stated interval, i.e. with an increase in the content of VK units from 25 to 100 mol. %, as well as with a decrease in their content below the declared, i.e. from 7 and less mol. % (Fig. 1, curves 5, 6).

The analysis of the scientific and technical level did not allow to find the published solution, which completely coincided in the aggregate of essential features with the claimed invention. This confirms the conclusion that the proposed solution meets such a patentability condition as “novelty”. The analysis of the patent base of the USA and the Russian Federation also did not allow to find such technical solutions that described the preparation of any copolymers of N-vinylcarbazole and N-vinylcaprolactam.

The possibility of obtaining metal-polymer solid solutions based on copolymers of the claimed composition with promising photoluminescent properties only in the polymethyl methacrylate matrix was not obvious, especially since solutions of Tb ³⁺ ions and the indicated copolymers in dimethylformamide practically do not luminesce, and weakly luminesce in other solid polymer solutions except polymethyl methacrylate .

Finding the previously unknown functional dependence of the composition is a property, namely, the luminescence intensity of terbium ions in solid solution on the content of vinylcarbazole units in the VK-ON copolymer, allows us to conclude that the claimed solution as a whole matches the patentability condition as “inventive step” (non-obviousness).

The obtained characteristics are confirmed by the drawings.

Figure 1 - luminescence spectra of solid solutions of (co) polymers and terbium ions in polymethyl methacrylate. Figure 1 presents the luminescence spectra of copolymers and terbium ions: VK: ON = 17: 83 (curve 1), 21:79 (curve 2); copolymer VK: ON (without terbium ions) = 17: 83 (curve 3); terbium (curve 4); poly-N-vinylcarbazole and terbium ions (curve 5); poly-N-vinylcaprolactam (content of ON units = 0.6 wt.%) and terbium ions (curve 6). The content of Tb ³⁺ = 0.64 wt.% (Curves 1, 2, 4-6), the content of VK units = 0.8 wt.% (Curves 1-3, 5). The molar ratio [Tb ³⁺ ]: [VK] = 1 (curves 1, 2, 5). The molar ratio [Tb ³⁺ ]: [ON] = 1 (curve 6). On the X axis - wavelengths (λ, nm). On the Y axis, the intensity of the luminescent glow in arbitrary units (I _lum , conventional units). The wavelength of the exciting light λ _exc = 300 nm. The luminescence intensities were obtained under comparable amplification conditions.

Figure 2 - luminescence spectrum of a solution of a copolymer VK: ON and terbium ions in dimethylformamide. Figure 2 represents the luminescence spectrum of a VK: ON = 17: 83 copolymer containing terbium ions in dimethylformamide. The concentration of VK units of 10 ^-3 mol / l, [Tb ³⁺ ]: [VK] = 1. On the X axis - wavelengths (λ, nm). On the Y axis, the intensity of the luminescent glow in arbitrary units (I _lum , conventional units). The wavelength of the exciting light λ _exc = 300 nm.

Figure 3 - luminescence spectra of solid solutions of a copolymer VK: ON and terbium ions in matrices of various nature. Figure 3 presents the luminescence spectra of a solid solution of a VK: ON = 21: 79 copolymer and terbium ions in polystyrene (1), poly-N-vinylpyrrolidone (2) and polymethylmethacrylate (3). The content of the units VK = 0.8 wt.%, The content of Tb ³⁺ = 0.64 wt.%, The molar ratio [Tb ³⁺ ]: [VK] = 1. On the X axis - wavelengths (λ, nm). On the Y axis, the intensity of the luminescent glow in arbitrary units (I _lum , conventional units). The wavelength of the exciting light λ _exc = 300 nm. The luminescence intensities were obtained under comparable amplification conditions.

To confirm the conformity of the claimed invention to such a condition of patentability as “industrial applicability”, and to better understand the essence of the claimed invention, we give examples of specific implementations of the invention, which cannot exhaust its essence.

Example 1

Obtaining a copolymer of N-vinylcaprolactam with N-vinylcarbazole

347 mg of N-vinylcaprolactam (2.49 mmol) and 54 mg (0.279 mmol) of N-vinylcarbazole, 0.69 ml of dimethylacetamide containing 0.55 mg of azoisobutyric acid dinitrile are added to the ampoule. The ampoule with the reaction mixture is evacuated and filled with argon. A sealed ampoule is placed in a thermostat with a temperature of 60 ° C. After 72 hours, the copolymer was isolated from the solution by precipitation into sulfuric ether, reprecipitated from dimethylformamide into ether and dried in vacuo at room temperature to constant weight. The copolymer yield is 215 mg (54%), the content of N-vinylcarbazole units is 17 mol. %, [η] = 0.13 dl / g.

The data of examples 2-3 of obtaining copolymers VK: ON with different content of comonomers are shown in the Table and performed under the conditions of example 1.

Example 4

Preparation of solid solutions containing a copolymer of N-vinylcarbazole and N-vinylcaprolactam, Tb ³⁺ ions in polymethyl methacrylate

Prepare a solution of a copolymer of N-vinylcarbazole and N-vinylcaprolactam obtained in example 1, the polymer concentration in the solution with _gender = 5 mg / ml, which corresponds to a concentration of VK units of 5.74 × 10 ^-3 mmol / ml. To 0.348 ml of a copolymer solution, 0.87 ml of dimethylformamide, 0.75 ml of a solution of TbCl ₃ with _TbCl3 = 1 mg / ml are added, and the molar ratio [Tb ³⁺ ]: [VK unit] = 1. To the resulting solution add 0.5 ml of a solution of polymethyl methacrylate with a concentration of c = 100 mg / ml, MM = 3.5 × 10 ⁵ Yes. The resulting mixture was thoroughly mixed and incubated for 30 minutes. Then cast on a glass substrate. The film is dried at 60 ° C to constant weight. The luminescence intensity of ions Tb ³⁺ I ₅₄₃ = 700 conventional units

Examples 5-8 for the preparation of solid solutions of copolymers with Tb ³⁺ ions with different contents of VK units in the polymethyl methacrylate matrix were performed under the conditions of Example 4 with varying amounts of the copolymer solution, all data are shown in the Table.

The conditions for obtaining the claimed copolymers and solid solutions Example Composition, pier. % Exit, % [η], dl / g The content of VK links in PMMA, wt.% I _lum , _conventional units monomer mixture copolymer m n m n 7 2 3 four 5 6 7 8 9 one 10 90 17 83 54 0.13 2 four 96 7 93 23 0.13 3 12 88 21 79 34 0.16 four 17 83 * 0.8 700 5 21 79 * 0.8 620 6 7 93 * 0.8 344 7 21 79 * 0.7 580 8 21 79 * 0.9 660 * Solid solution in the form of a film. [η] cannot be determined.

The data presented confirm the achievement of the stated objectives. Going beyond the stated composition of the copolymer, the content of Tb ³⁺ ions, the concentration of the copolymer in the solid solution leads to a sharp drop in the luminescence value.

The Tb ³⁺ obtained for the first time, containing solid solutions in polymethyl methacrylate based on VK-ON copolymers of the claimed composition, are characterized by high luminescence intensity - from 344 to 700 conventional units The claimed solid solutions of VK-ON copolymers with Tb ³⁺ ions may be of interest for creating laser, luminescent, electroluminescent, high-speed switching devices.

Claims (2)

1. Copolymers of N-vinylcarbazole with N-vinylcaprolactam of the general formula:

where m: n = (7-21) :( 93-79) mol. %; [η] = (0.13-0.16) dl / g. 2. Solid solutions of polymethylmethacrylate, including Tb ³⁺ ions and copolymers of N-vinylcarbazole with N-vinylcaprolactam of the general formula:

where m: n = (7-21) :( 93-79) mol. %; [η] = (0.13-0.16) dl / g, molar ratio [Tb ³⁺ ]: [N-vinylcarbazole unit] = 0.8-1.1 the content of N-vinylcarbazole units in the solid solution of polymethylmethacrylate 0, 7-0.9 wt.%.

Images