Polymethylsiloxane polyhydrate having supramolecular properties of molecular capsule, method for production of the same, and sorbent containing the same

Abstract

To provide a method for producing a sorbent having selective properties, in particular, a method for producing polymethylsiloxane polyhydrate (methylsilicic acid hydrogel) used in chemistry, medicine, and veterinary medicine.SOLUTION: According to the method, polycondensation of a metasil solution is carried out using acid. The solution is obtained by mixing, at a temperature of 90°C or more, 0.84 to 1.00 mol of alkali per 1 mol of polymethylsiloxane contained in methylsilanetriol, and, in the best embodiment of the invention, in the range of 0.84 to 0.90 mol, and by adding an electrolyte in an amount of 0.025 to 0.1 mol per 1 mol of alkali. The resulting polymethylsiloxane polyhydrate has the supramolecular properties of a molecular capsule.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for the preparation of absorbents with supramolecular properties of molecular capsules. In particular, the present invention relates to a method for the preparation of polymethylsiloxane polyhydrates (methylsilicic acid hydrogels) for use in chemical, medical and veterinary medicine. [Background technology]

[0002] Polymethylsiloxane polyhydrate (hereafter referred to as PMSPH) is produced from an alkaline (potassium hydroxide or sodium hydroxide) solution of methylsilanetriol (methylsilanetriol, CAS 2445-53-6, https: / / pubchem.ncbi.nlm.nih.gov / compound / 61844).

[0003] Methylsilanetriol is a hydrolysis product of methyltrichlorosilane (methyltrichlorosilane, CAS 75-79-6, https: / / pubchem.ncbi.nlm.nih.gov / compound / 6399), a polymeric granular material with a water content of 40-60%, with the following molecular formula: [(CHSi) n O (n-1+k) (OH) (n+2-2k) ]·pH2O (wherein n is the number of bonds, k is the branching index that determines the degree of crosslinking or branching and is expressed by the following formula: 0≦k≦[n+2-(n mod 2)] / 2 where mod is a mathematical function that returns the remainder when one number is divided by another, p is external water, i.e., water that is not chemically bound, n:(n / 2-k+1+p)=1:(2.5÷5.6). has.

[0004] As can be seen from the overall formula of methylsilanetriol, it belongs to the class of polymethylsiloxanes, and in the following text, instead of the term "methylsilanetriol (dehydrated)", the more accurate terms "polymethylsiloxane (PMS)" or "polymethylsiloxane in methylsilanetriol" will be used.

[0005] The properties and methods of preparation of polymethylsiloxanes, including detailed information on the synthesis and properties of organosilicon compounds, are described in various publications, including RG Jones, W. Ando, ​​J. Chojnowski "Silicon-Containing Polymers: The Science and Technology of Their Synthesis and Applications", Springer Science & Business Media, 2013, 768 pages. An extensive overview of the principles and mechanisms of formation of materials using sol-gel processes, synthesis methods, characteristics and properties is provided in a book by S. Sakka "Handbook of Sol-Gel Science and Technology", Kluwer Academic Publishers, 2005, 1986 pages.

[0006] Information regarding the characteristics of siloxane bonds and their influence on the physical properties of compounds, as well as a review of the polycondensation processes of silanols and siloxanols, is given in MG Voronkov, VP Mileshkevich and Yu. A. Yuzhelevsky "Siloxane Linkage", Novosibirsk, Nauka, 1976, 413 pages.

[0007] In addition, a number of patents describe the discovery of some special properties in the polyhydrate form of polymethylsiloxane. Russian Patent No. 2761627 (December 01, 2020) describes a method for producing PMSPH from sodium methylsiliconate and hydrochloric acid. The characteristics of the reagents used are as follows: the density of the sodium methylsiliconate solution is 1.2-1.3 g / cm 3 the concentration of the hydrochloric acid solution was 12.0-14.0%. The authors crushed the formed gel and washed it until it was neutral. The resulting product showed particularly high adsorptive properties.

[0008] Russian Patent No. 2111979 (March 11, 1994) discloses a method for producing methylsilicic acid hydrogels from sodium or potassium salts of methylsiliconate and strong acids (hydrochloric acid or sulfuric acid, according to the claims of the invention). The authors characterize the solutions of the sodium and potassium salts of methylsiliconate with a quantitative content (1.75-2.30 mol / L).

[0009] Certificate of Invention No. SU137113 (August 19, 1960) describes the preparation of a highly disperse and hydrophobic methylsilicic acid hydrogel powder by mixing sodium methylsiliconate and acetic acid. Although the authors call the product "silica", the chemical formula of the final compound is similar to PMSPH. The concentration of the sodium methylsiliconate solution is 12.5%.

[0010] Although it is possible to include various useful chemical and / or biological additives in the aforementioned technical solutions, the considered technical solutions are mainly aimed at producing products with high adsorption properties, and the additives do not have a significant effect on improving the absorption properties of the resulting product.

[0011] New possibilities for utilizing the properties of methylsilicic acid hydrogels are disclosed in Ukrainian (UA) Patent No. 115857 (August 30, 2017). The patent describes a method for producing methylsilicic acid hydrogels with supramolecular properties. Polycondensation of methylsiliconate solutions was carried out with the aid of gaseous acid agents. The resulting supramolecular properties were achieved for the first time, but the method is difficult to implement, requires special equipment and the work is carried out at high pressure.

[0012] Russian Patent No. 2293744 (December 22, 2005) describes the prototype closest to the technical solution being considered for the practical production of PMSPH. The patent gives the basis for the chemical formula of the final product of polymethylsiloxane polyhydrate, but does not address the issue of the composition of the alkaline stock solution of sodium dihydroxymethylsilicate, indicates that the composition of this solution contains only one substance, and indicates a narrow range of water content only for the gel form of the substance. Moreover, the patent does not consider the possibility of imparting supramolecular properties to the product. Summary of the Invention [Problem to be solved by the invention]

[0013] None of the above technical solutions pays enough attention to the problem of the composition of sodium methylsiliconate or the quality of the initial solution of methacyl. These problems lead to the generation of low molecular weight fractions during the polycondensation process, which affects the properties of the obtained product (i.e., the quality is reduced) by reducing the purity, inhibits the substitution reaction, and reduces the yield of the obtained product.

[0014] The present invention solves the technical problem of producing polymethylsiloxane polyhydrate with supramolecular properties of molecular capsule quality, and improves the yield and purity of the resulting products. [Means for solving the problem]

[0015] In order to solve the above problems, the method proposed for producing polymethylsiloxane polyhydrate with the supramolecular properties of molecular capsules involves reacting an acid with a polycondensed methacyl solution, mixing an alkali in a ratio of 0.84 to 0.9 moles per mole of polymethylsiloxane contained in methylsilanetriol, and an electrolyte in an amount of 0.025 to 0.1 moles per mole of alkali, at a temperature of 90°C or higher. The alkali is sodium hydroxide or potassium hydroxide.

[0016] The electrolyte can be a chloride, bromide, iodide, nitrate, nitrite, carbonate, sulfate, sulfite, acetate, oxalate, succinate, formate, citrate salt of lithium, sodium, potassium, ammonium, or a mixture of these salts.

[0017] The electrolyte not only enhances the supramolecular character of the material but also contributes to the modification of the q range.

[0018] The addition of electrolytes to alkaline aqueous solutions of methylsilanetriol leads to the formation of unique polymethylsiloxane polyhydrates (PMSPH) with supramolecular properties such as molecular capsules, which represents a new direction in the field of materials properties.

[0019] Polymethylsiloxane polyhydrate having supramolecular properties has the following chemical structure:

[0020] [ka]

[0021] The resulting PMSPH has a high absorption capacity, which makes it a useful absorbent. The structure of PMSPH can be described as a dimer of variable composition with a polyhydrate shell.

[0022] The chemical formula of polymethylsiloxane polyhydrate and its properties changed with the change in the range of n. [Brief description of the drawings]

[0023] [Figure 1] This is a diagram showing the formation region of m-mers (1≦m≦3) when methylsilanetriol is dissolved in alkali, in which the lower set of lines for (8≦n≦∞) represents trimers, the middle set of lines represents dimers, and the upper set of lines represents monomers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] By confirming the composition of the methacyl solution containing a set of dimeric siloxanolate derivatives, the authors of the present invention detailed the chemical formula of polymethylsiloxane polyhydrate, expanded the water content range of the gel form of the material, and determined the water content range of the paste-like and suspension forms of the material. By adding an electrolyte solution to the methacyl solution, the authors of the present invention produced a compound with the supramolecular properties of a unique molecular capsule.

[0025] To assess the completeness of branching of a polymer, the normalized bond index (I(b)) is used in conjunction with the degree of crosslinking or branching index (k). The value of I(b) ranges from 0 (0%) to 1 (100%), with I(b)=0 corresponding to a linear polymer structure and I(b)=1 corresponding to a fully condensed structure.

[0026] The relationship between the I(b), k, and k(max) indices is given by the following ratio: I b =k / (k(max)); k(max)=[n+2-(n mod 2)] / 2 is defined as:

[0027] In the process of preparing an alkali (the conventional symbol for alkali is MeOH) solution of polymethylsiloxane, the interactions are described by the following steps: Stage 1: Debranching of the molecule by cleavage of the intramolecular siloxane bonds under the influence of alkali. Stage 2: Breaking the siloxane bonds of larger molecules to form smaller molecules. Stage 3: Replacement of the hydroxyl group with an alkali metal cation to form an OMe group.

[0028] Below we consider each stage in detail. Note that in the following reaction schemes, water is not shown in the chemical formulas of the compounds, as water does not chemically interact in these reactions.

[0029] (Stage 1) The chemical reaction at this stage is as follows:

[0030] [ka]

[0031] The amount of alkali consumed in this stage is proportional to the degree of branching of the initial polymethylsiloxane molecule.

[0032] (Stage 2) The chemical equation involving the formation of an intermediate and subsequent separation of an m-dimensional fragment from the n-dimensional main molecule is:

[0033] [ka]

[0034] The formation of a small molecule of m dimensions (m-mer) from an n-dimensional molecule proceeds according to the following reaction:

[0035] [ka]

[0036] In the formula, A is m×(xy), B is (nm)×(xy), D is m×(nk−1)+n×(1−y), and E is m×(kn−1)+n×(x−1).

[0037] (Stage 3) In the presence of an equivalent or excess amount of alkali, substitution reactions of small linear fragments are possible. The chemical reaction is as follows:

[0038] [ka]

[0039] All three of these stages are possible and may occur during the interaction of the polymethylsiloxane contained in the methylsilanetriol with an alkali.

[0040] The objectives of the proposed invention are the theoretical evaluation of the process for the preparation of the interaction product of methylsilanetriol with alkali, the practical validation of this theoretical evaluation, the improvement of the method for the optimization and control of the process for the preparation of an alkaline solution of methylsilanetriol and the subsequent production process of polymethylsiloxane polyhydrate (PMSPH).

[0041] Combining stages 1 and 2 (chemical reaction equations (1) and (2.1)) made it possible to study models for the production of fragments of smaller dimensions and to carry out their quantitative and qualitative evaluation. For this purpose, reaction equations were derived and the stoichiometric coefficients of the reaction equations were calculated. To enable the calculations, a method was chosen for assembling half-reaction equations with the formation of two fragments (m-mers) of the same dimensionality. Taking into account the conditions for the formation of the reaction products, the half-reaction equations were combined to derive the general reaction equation. The initial premise was that in the process of the interaction of polymethylsiloxane with alkali, m-dimensional fragments are formed, and the possibility of forming reaction products of dimensions from monomers (m = 1) to trimers (m = 3) was taken into account.

[0042] The chemical equations for the stage 1 and stage 2 reactions are as follows:

[0043] [ka]

[0044] where A is m(xy), B is m(xy)×(n / m+k−1), D is m(n−k+1)+n(1−y), and E is m(kn−1)+n(x−1), with a common range for k being 0≦k≦[n+2−(n mod 2)] / 2, and for the possibility of forming products (D≧0;E≧0), the range of k values ​​is (n(1−(x−1) / m)+1)≦k≦(n(1−(y−1) / m)+1), where 1≦m≦3, 1≦x≦(m+2), and 0≦y≦(x−1).

[0045] To obtain smaller fragments of dimension m, the alkali consumption depends on the size of these fragments (the m value) and has a ratio of ((k-1) / n+1 / m) moles of alkali per mole of polymethylsiloxane.

[0046] In order to determine the ratio of alkali and PMS in the manufacturing process of the previously patented polymethylsiloxane polyhydrate (Russian Patent No. 2293744 (December 22, 2005)), the balance of production materials at the stage of production of Metasil was investigated. As a result, it was found that the practical ratio of alkali and PMS at the stage of producing methylsilicone solution is 0.85 ± 0.05 moles of alkali to 1 mole of PMS. The ratio of components used by the authors was less than 1, so the statement that an alkaline solution of polymethylsiloxane is a known product of sodium methylsiliconate (CAS 4493-34-9, https: / / pubchem.ncbi.nlm.nih.gov / compound / 23704354) or potassium methylsilanetriolate (CAS 18089-65-1, https: / / pubchem.ncbi.nlm.nih.gov / compound / 23689131, CAS 65351-55-5, https: / / pubchem.ncbi.nlm.nih.gov / compound / 6455118) is incorrect.

[0047] Therefore, the substance that the authors have produced in the process of dissolving polymethylsiliconate contained in methylsilanetriol in alkali is novel. The authors propose to call this substance "Metasil solution."

[0048] Modeling the composition of the reaction products using Reaction Scheme (4), and further preparing and studying samples of the materials described by these models, has yielded results unknown in the prior art.

[0049] There is no direct way to determine the structure of methylsilanetriol, because it contains hydroxyl groups that under slight influences (changes in acidity, temperature, and other chemical and physical factors) contribute to rearrangement of non-condensed hydroxyl groups and changes in structure and composition. In addition, the material contains physically bound water, which represents a separate phase.

[0050] Since methylsilanetriol is a hydrolysis product of methyltrichlorosilane, this substance is a spatially crosslinked polymer with various compositions, containing an assembly of molecules with various lengths (different n values) and various branching index values ​​k (MG Voronkov, Yu. N. Murinov et al., "Influence of conditions of hydrolytic polycondensation of methyltrichlorosilane on the sorption properties of the resulting silicon polymers", High-molecular compounds, Series A, 2000. v. 42, No. 7, pp. 1175-1182). Based on the data provided by the authors of this paper, the bond index in the structures of the products obtained using various process schemes was calculated. The values ​​of the I(b) bond index of the obtained substances were in the range of 0.4-1, with an average value of 0.76. The average value of the I(b) bond index is in the range of 0.62-0.88.

[0051] It should be noted that methylsilanetriol does not consist of a chain molecule, because the hydrogen chloride produced as a by-product during the hydrolysis of methyltrichlorosilane has the chemical formula [(CH3Si) n O (n-1) OH (n+2) ]·pH2O does not allow the formation of completely chain-like molecules. M. Kopylov, LM Khanashvili, OV Shkolnik, AG Ivanov, "Organochlorosilanes hydrolytic polycondensation (review)", High-molecular compounds, Series A, 1995, v. 37, No. 3, pp. 394-416). In this regard, the value of the k branching index or I(b) bond index is always greater than zero. For structures with branching index k=k(max) or I(b)=1, the structure does not contain hydrophilic groups, so the characteristics are hydrophobic. If methylsilanetriol is added to water and the solution is subsequently evacuated to remove air, methylsilanetriol will completely settle to the bottom of the container. This fact indicates that there are no structures with branching index k=k(max) or I(b)=1 in the composition of methylsilanetriol. Thus, methylsilanetriol is a spatially crosslinked molecule with the following general formula: (CH3Si) n O (n-1+k) (OH) (n+2-2k) ]·pH2O During the ceremony, n is the number of bonds, k is the branching index, 0≦k≦[0.5n−0.5(n mod 2)]; p is external water, i.e., water that is not chemically bound, n is (n / 2-k+1+p)=1:(2.5÷5.6).

[0052] To determine the composition of the m-mer of the PMS solution in alkali, the authors calculated the reaction products according to Reaction Formula (4). The boundary of the m-mer formation region was calculated based on the dependence of the component ratio of alkali:PMS on the I(b) bonding index in the initial polymethylsiloxane. The following points were considered when performing the calculation. · The polymethylsiloxane of methylsilanetriol does not contain a complete chain structure (k = 0), a cyclic structure (k = 1), and a complete bond structure (k < k(max) - 1) in its composition (under the condition in the form of 2 ≦ k ≦ (0.5n - 0.5(n mod 2))). · Considering the above conditions, the minimum number of units (n) in the polymethylsiloxane of methylsilanetriol is 8. · The maximum number of units (n) in methylsilanetriol becomes infinite (n → ∞). · To eliminate the dimensionless of the component ratio function, the I(b) normalized bonding index was used as the argument of the function.

[0053] The function of the bonding index dependence of the component ratio (mol / mol) is as follows.

[0054]

Equation

[0055] In the formula, [MeOH / PMS] is the molar ratio of the components when PMS is dissolved in alkali, n is the number of units of the polymethylsiloxane contained in methylsilanetriol, k(max) is the maximum possible branching within the PMS molecule of n units (k(max) = [n + 2 - (n mod 2)] / 2), I(b) is the bonding index (I(b) = k / (k(max))), m is the dimension of the m-mer obtained as a result of the reaction (1 ≦ m ≦ 3).

[0056] Figure 1 shows the comparison between the formation region of the m-mer and the ratio of the components actually used in the production of PMSPH.

[0057] In FIG. 1, a series of lines represents the region where m-mers are formed during the dissolution of polymethylsiloxane of methylsilanetriol in alkali (8≦n≦∞, where the monomer is the top plot line, the dimer is the middle plot line, and the trimer is the bottom plot line). As a result, a set of plot lines (different n values ​​of PMS) with a slope ratio (0.5+1 / n) limits the minimum value of the component ratio to obtain a given m-mer. Thus, to form a monomer (m=1, top set) from a PMS with a bond index of 0.1≦I(b)≦0.41, the ratio of alkali components must be 1.20 or more. To form a monomer from a PMS with a bond index of 0.42≦I(b)≦0.77, the ratio of alkali components:PMS must be 1.20:1 or more. To form monomers from PMS with a bond index of 0.42≦I(b)≦0.77, the ratio of alkaline component:PMS must be greater than 1.39:1. The graph shown in FIG. 1 provides a clear idea that when the ratio of alkaline component:PMS is at the level of 0.8:1 (component ratio calculation for the production of PMSPH according to Russian Patent No. 2293744), the reaction products are dimers obtained from PMS with a bond index of 0≦I(b)≦(0.60-0.66), as well as trimers with a bond index of (0.60-0.73)≦I(b)≦0.94. When the ratio of alkaline component:PMS is at the level of (0.83-0.9):1, the reaction products are only dimers obtained from PMS with a bond index of 0-0.83. The data obtained are consistent with the source by MG Voronkov, Yu. N. Murinov et al., "Influence of conditions of hydrolytic polycondensation of methyltrichlorosilane on the sorption properties of the resulting silicon polymers", High-molecular compounds, Series A, 2000, v. 42, No. 7, pp. 1175-1182, which shows that alkaline solutions of polymethylsiloxanes are CH3Si(OH) x (ONa)(3-x) or CH3Si(OH) x (OK) (3-x) This confirms the above conclusion that the compound is not a product of sodium methyl siliconate or potassium methyl siliconate having the chemical formula:

[0058] For each of the PMS structures in methylsilanetriol, when using PMS consisting of structures with branching index of 0≦k≦k(max), the amount of alkali required to allow the formation of monomer (m=1) ranges from 0.9 moles (for k=0) to 1.5 moles (for k=k(max)) per mole of PMS. When the alkali is used in a molar ratio to PMS ranging from 0.45 (for k=0) to 1.0 (for k=k(max)), the reaction product is a dimer (m=2). To form a trimer (m=3), the ratio must be 0.28-0.83. The ranges of ratios for the formation of dimers and trimers overlap, so to obtain the strict dimer, the molar ratio of alkali to PMS should be used in the range of 0.84-1.0. Assuming that in practice the PMS contained in methylsilanetriol does not consist of structures covering the entire range of k-branching indices, and taking into account that the maximum practical molar ratio of alkali to PMS is 0.9, the recommended range of alkali to PMS molar ratios to obtain the dimer is 0.84-0.9. Thus, according to the presented data, the authors concluded that by varying the alkali:PMS molar ratio, it is possible to carry out a controlled synthesis of the m-mer while obtaining the predicted reaction products.

[0059] In connection with the above, it has become apparent that in a practical process for the preparation of an alkaline solution of methylsilanetriol, the formation of the product described in stage 3 (the substitution reaction according to equation (3) with the formation of an OMe group) does not occur.

[0060] It was unexpected that the resulting alkaline solution of methylsilanetriol contained all possible dimer structures. For the dimers, molecules containing two OMe groups were expected to be the predominant components. The actual composition of the methylsilanetriol solution in alkali is shown in Table 1.

[0061] [Table 1]

[0062] Due to the fact that the mixtures obtained in practice have a heterogeneous composition, a new problem arises: obtaining homogeneous mixtures for the purpose of further study, standardization and possible comparison with real mixtures. To solve this problem, theoretical calculations were used. Thus, in the process of carrying out stages 1 and 2, it is possible to obtain a homogeneous mixture of dimers with a ratio of methylsilanetriol:alkali of 1:1 for a substance with the value k = (n / 2 + 1) (I (b) = 1), or a homogeneous mixture of monomers with a ratio of methylsilanetriol:alkali of 1:1.5. The composition of the dimer mixture is shown in Table 1 (MeOH / PMS ratio = 1.0). Since the dehydrated methylsilanetriol has this structure, there is no problem in obtaining a substance with k = (n / 2 + 1) (I (b) = 1). The dehydration of methylsilanetriol can be carried out by any available method, such as thermal or low-temperature drying, drying at atmospheric pressure or in vacuum. The authors dehydrated methylsilanetriol using vacuum drying (temperature 70–80°C, pressure 0.03–0.05 MPa).

[0063] During the gelation process of PMSPH from an alkaline solution of methylsilanetriol using an acid solution, several parallel processes occur in the system: Growth of the structure by intermolecular cross-linking with the formation of salts of the MeA type (where Me is an alkali metal and the cation A is an anion) as reaction products. Polycondensation of structures with intramolecular crosslinking, mainly caused by OH groups; Replacement of OH groups by OMe or A groups through reversible substitution reactions by interaction with reaction products with intermolecular bridges.

[0064] The polycondensation process with intermolecular crosslinking occurs at different rates and slows down as the viscosity of the system increases. Compared to the other processes described, polycondensation with intermolecular crosslinking has the highest rate. This process involves OMe groups.

[0065] The process of polycondensation of the internal molecular structures occurs at a slower rate, is reversible, and depends on the acidity, viscosity, temperature, and molecular size of the system. This process mainly involves OH groups, which are therefore less reactive than the OMe groups in the previous process.

[0066] The substitution reaction is the slowest process and depends on the concentration and viscosity of the salt produced. The first process (polycondensation with intermolecular cross-linking) occurs, so Me (+) A cation is formed. This cation is the H of the uncondensed OH group. (+) It can undergo substitution reactions with ions to form OMe groups.

[0067] At the gelation point, the reaction mixture separates into two parts: an insoluble gel and a soluble sol. The insolubility of the gel is explained by the fact that the gel is a spatial network, in which the individual chains are chemically tightly bound to each other. At the gelation point, the number-average molecular weight is small, and the mass-average molecular weight is infinite (SV Vdovina, E.Yu. Bondyreva "Polycondensation: Guidelines for self-study", Nizhnekamsk, Nizhnekamsk Institute of Chemical Technology, branch of the Federal State Budgetary Educational Institution of Higher Professional Education "KNITU", 2014 , 28 p.).

[0068] After reaching the gel point, the amount of sol starts to decrease rapidly due to the transition to gel. The viscous reaction mass changes first to an elastomeric material and then to a solid, insoluble and insoluble product. Along with intermolecular processes, reactions can also occur between functional groups of the same network structure.

[0069] All the above arguments support the assertion that PMSPH produced from alkaline solutions of methylsilanetriol with MeOH / PMS molar ratios between 0.84 and 0.9 is a dimer of variable composition with a polyhydrate shell and a tendency to infinitely large mass average molecular weight. Structurally, such polymethylsiloxane polyhydrates are represented by the following chemical formula:

[0070] [ka]

[0071] where, for products in the form of gels, a range of q from 60 to 92 is typical; For products in paste form, a q range of 89 to 134 is typical; For products in the form of a suspension, a range of q from 133 to 241 is typical.

[0072] The authors modeled a polycondensation process involving intermolecular cross-linking. To this end, they generated random half-reactions between the initial m-mers, evaluated the possibility of (m+m)-mer formation, compiled the balance of intermediate and final steps of the interaction, and calculated the next step of the process.

[0073] The results show that at each stage of the process, m-mers containing a full set of low-reactivity OH groups (e.g., (CH3Si)4O3(OH)6, (CH3Si)8O7(OH) 10 At the same time, m-mers (e.g., (CH3Si)4O3(OH) x (OMe) 6-x(in the formula, 1≦x≦5), (CH3Si)8O7(OH) x (OMe) 10-x (where 1≦x≦9), or a full set of reactive OMe groups (e.g., (CH3Si)4O3(OMe)6, (CH3Si)8O7(OMe) 10 The number of fluorescein fragments was reduced. This data was confirmed by the presence of low molecular weight fragments in the IR spectrum.

[0074] As mentioned above, the low reactive m-mers present are capable of intramolecular condensation once they reach a certain size. The accumulation of low molecular weight fragments (tetramers, octamers, etc.) does not result in the normal progression of the gelation process, but actually blocks the main product with fine fragments, resulting in a decrease in the practical yield of the desired product (PMSPH) and preventing the substitution reaction of OH groups with OMe groups (the substitution process mentioned above).

[0075] The authors have succeeded in eliminating the aforementioned problems, improving the yield of the desired product and suppressing the formation of low molecular weight fragments during gelation of PMSPH. The claimed results are achieved by additionally adding to the mixture, in the step of forming the dimer in the process of dissolving methylsilanetriol in alkali, an electrolyte in an amount of 0.025 to 0.1 mole per mole of alkali used. The electrolyte is a salt or mixture of alkali metal or ammonium salts. An unexpected result was that the gel of polymethylsiloxane polyhydrate precipitated by the acid solution exhibited supramolecular properties.

[0076] The supramolecular nature of a substance refers to the properties and behavior of complex structures formed from molecules through intra- and intermolecular interactions. Along with strong and directional chemical bonds, weaker intermolecular interactions such as hydrogen bonds, hydrophobic interactions, ion-dipole interactions, van der Waals interactions, etc. occur over longer distances and are not restricted to a specific direction.

[0077] The properties of supramolecules include the following: · Self-assembly: The ability of molecules to form well-defined structures without external influence. · Recognition and binding: The ability of a molecule to interact and bind to other molecules through specific interactions such as host-guest interactions. · Supramolecular chemistry: exploiting weak intermolecular interactions for the controlled synthesis and manipulation of complex structures. · Materials properties: the ability of supramolecular systems to have unique physical and chemical properties, such as viscosity, optical properties, electronic properties, self-healing ability, and the ability to change structure under the influence of external stimuli.

[0078] The ability to control the structure of supramolecular systems under external influences (e.g., changes in the properties of the environment, such as light, force fields, etc.) opens up the possibility of controlling the structure of the resulting supramolecular material (crystal or polymer) and its properties.

[0079] The property of a material to trap molecules of other materials within its own cavity or cavities by polycondensation of the end groups of the cavities can be termed "guest trapping by intra- or intermolecular polycondensation". This property is based on the ability of a material to form polymer chains by intra- or intermolecular polycondensation reactions between end groups.

[0080] This property may be key to creating supramolecular materials that can efficiently bind and confine guest molecules within their structure, which could be useful for drug storage and delivery, catalysis, sensing, and other applications where controlled encapsulation and release of guest molecules plays a key role.

[0081] A known class of materials with supramolecular properties are molecular capsules (Donald J. Cram, Jane M. Cram "Container Molecules and Their Guests", University of California, Los Angeles, USA, 1994). Molecular containers (capsules) are formed by the self-organization of molecules of a material. They can be organic or inorganic in nature and have a cavity that confines a guest molecule. One of the main characteristics of molecular capsules is their ability to close or "plug". In particular, this occurs through a polycondensation or polymerization reaction that can occur with the end groups of the material, which forms the shell of the molecular capsule. Polycondensation allows the end groups of the shell molecules to bond, closing the shell and forming a stable structure.

[0082] The closed cavity of the molecular capsule protects and retains the guest substance molecules inside, which may be useful for: · Controlled drug delivery. · Encapsulation of harmful, toxic or targeted substances with subsequent expulsion of the "closed" molecular capsule and further availability of the substance after "opening" of the molecular capsule. Catalysis of chemical reactions. · Creation of unique reaction media for fine chemical synthesis.

[0083] Molecular capsules are an active area of ​​research in nanotechnology and supramolecular chemistry, with potential uses in a variety of applications including medicine, chemistry, energy, and materials science.

[0084] Based on the assumption that PMSPH has these properties, the supramolecular properties of PMSPH prepared according to the proposed method were evaluated: The guest substance (marker substance) cannot be quantitatively determined in a separate phase (e.g., the solvent of the guest substance) because it is encapsulated (trapped) in the PMSPH molecular capsule as a result of affecting the PMSPH molecule with factors that cause the molecular capsule to become trapped. · As a result of influencing the PMSPH molecule with a factor that releases the molecular capsule, the guest substance (marker substance) can be quantitatively determined by any method in a separate phase (e.g., the solvent of the guest substance) since it is no longer encapsulated (trapped) in the PMSPH molecular capsule.

[0085] The unlocking of the molecular capsule tends to occur after the guest substance has been entrapped within the molecular capsule.

[0086] If PMSPG does not exhibit the sequential property of trapping and releasing guest substances, it means that this GMSPH does not have supramolecular properties and does not form molecular capsules. EXAMPLES

[0087] (Measurement of supramolecular properties of polymethylsiloxane polyhydrate (PMSPH)) 1. A weighed portion of PMSPH with a known specific sorption capacity for the marker substance in the pH range of 1.0-10.0 was quantitatively transferred to the column and compressed with a plunger. The column is a glass or plastic tube with a diameter of 40 mm or more and a height of 200 mm or more, containing a filter, narrowed to a diameter of 3-5 mm, and with a two-way valve at one end.

[0088] 2. A solution of 0.0001-0.0005 M sodium hydroxide or potassium hydroxide was added to the column until the pH of the solution at the column outlet was in the range of 8.5-10.0. In a modified measurement embodiment, no alkaline solution was added.

[0089] 3. At the top of the PMSPH layer, a marker substance solution was added to the column in an amount calculated by measuring the specific sorption capacity of PMSPH. Methyl orange or bovine serum albumin (BSA) were used as marker substances. However, the list of marker substances is not limited to the above substances.

[0090] 4. After the mixture was held for 1.5-2 hours, which is necessary for the polymethylsiloxane to bind with the polyhydric hydrate of the marker substance, a calculated amount of 0.0001-0.0005M acid solution (hydrochloric acid or sulfuric acid or citric acid) was added to the column until the pH at the column outlet was in the range of 5.5-7.0. The excess solution was discharged from the bottom pipe of the column, the pH therein was controlled by potential difference, and the content of the marker substance was controlled by spectrophotometric analysis. In the modified quantitative embodiment, no acid solution was added.

[0091] 5. Purified water was poured into the column in a total weight of 5 to 10 times the weight of the PMSPH sample.

[0092] 6. The purified water was kept in the column for 1.5 to 24 hours and then discharged from the bottom pipe of the column.

[0093] 7. The solutions discharged from the column were examined for pH and for the content of marker substances using spectrophotometric analysis in the ultraviolet and visible regions. To qualitatively evaluate the content of the types of dissolved substances in the test solutions, spectrophotometric analysis in the UV region was carried out on purified water. When the presence of soluble substances was confirmed based on the results of the UV spectrophotometric analysis, spectrophotometric analysis in the visible region was carried out on a calibration curve solution of the marker substance. When BSA was used, the solution was additionally treated with Biuret reagent and spectrophotometric analysis of the resulting complex was carried out. Based on the results of calculating the amount of the marker substance in the test solution, the residue was determined and the remaining amount of the marker substance in the weight of PMSPH was calculated.

[0094] 8. A calculated amount of 0.0001-0.0005M acid solution (hydrochloric acid, sulfuric acid, or citric acid, not necessarily the same as that used in step 4) was added to the column to bring the pH to the range of 1.0-2.0. The mixture was held on the column for 0.5-6 hours, after which purified water was added in a total weight of 5-10 times the weight of the PMSPG sample (but the same weight as in step 5).

[0095] 9. The purified water was kept in the column for 1.5 to 24 hours and then discharged from the bottom pipe of the column.

[0096] 10. The solution discharged from the column was examined for pH and content of marker substance using spectrophotometric analysis in the ultraviolet region. Based on the calculated amount of marker substance in the test solution, the residual was determined and the remaining amount of marker substance in terms of the weight of PMSPH was calculated. The supramolecular character of PMSPH was calculated as the ratio of the weight of marker substance found in the solution in step 9 to the initial weight of marker substance loaded in step 3.

[0097] The supramolecular properties obtained were compared with data obtained by conventional methods and from PMSPH samples prepared for measurement as described above.

[0098] Example 1: Method for producing polymethylsiloxane polyhydrate having supramolecular properties of molecular capsules 210 g of methylsilanetriol containing 94.5 g of PMS was mixed with 49.8 g of sodium hydroxide (main content 98.5%). The final MeOH / PMS ratio (mol / mol) was 0.87. After heating the mixture, 1.79 g of sodium chloride (0.025 moles per mole of alkali) and 280 g of water were added. The total charge weight was 541.59 g. The mixture was held at 90 °C for 2 hours. The alkaline solution of methylsilanetriol was characterized as having an alkalinity of 3.1 moles / L, a content of 310.1 g / L, and a solution density of 1.17 kg / L. Gel formation was performed by mixing the alkaline solution of methylsilanetriol and a 3-3.5 M sulfuric acid solution in a volume ratio of 3-3.3:1. After aging the gel, it was crushed and first washed with 0.01-0.015% sulfuric acid solution until the acidity was 2.5-4.0, and further washing was performed with water that was purified to a pH value of 5.5-7.0 and free of electrolyte anions and sulfates.

[0099] (Measurement results of supramolecular properties of PMSPH and parameters of some steps of the measurement method of supramolecular properties according to Example 1) 1. The weight of PMSPH was 20.53 g. The dry residue was 10.03%. The absorption capacity for methyl orange was 2.28 mg / g and for bovine serum albumin was 1.2 mg / g. 3. The estimated loading per PMSPG sample weight was 46.8084 mg for methyl orange and 24.636 mg for bovine serum albumin. 4. The weight of the washed methyl orange was 0.4208 mg (0.9%). The weight of the washed bovine serum albumin was 0.223 mg (0.91%). 5. The weight of the water poured was 102.65g. 6. Exposure time to the solution was 9 hours. 7. The weight of the washed methyl orange was 1.3294 mg (2.84%). The weight of the washed bovine serum albumin was 0.3856 mg (1.57%). 10. The weight of the washed methyl orange was 36.2083 mg (77.35%). The weight of the washed bovine serum albumin was 19.6049 mg (79.58%). The weight of the methyl orange remaining in the complex with PMSPH was 8.8499 mg (18.91%). The weight of the bovine serum albumin remaining in the complex with PMSPH was 4.4225 mg (17.95%).

[0100] As can be seen from the data presented in Example 1, the entrapment capacity of PMSPH is 77% for methyl orange and 79% for bovine serum albumin. That is to say, the function of the acid in step 4 of the method for testing the supramolecular properties is to "entrap" the substance (methyl orange or bovine serum albumin) in the volume of PMSPH. The fact of "entrapment" is also confirmed by the presence of traces of the "entrapped" substance in the washing solution, even after keeping the complex in five volumes of water (steps 5 to 7). A part of the acid solution added to the complex in step 8 plays the role of a key, "liberating" the substance from the complex, which is then washed with water without binding and determined in solution (steps 9 to 10). The described properties of the obtained PMSPH characterize the product in terms of the presence of supramolecular properties that are absent in the PMSPH obtained by the conventional method (examples 2 to 3).

[0101] Example 2: Preparation of polymethylsiloxane polyhydrate by conventional method and testing of supramolecular properties (embodiment using sodium hydroxide) 210 g of methylsilanetriol containing 94.5 g of PMS was mixed with 51.5 g of sodium hydroxide (main content 98.5%). The final MeOH / PMS ratio (mol / mol) was 0.9. After heating the mixture, 290 g of water was added. The total charge was 551.5 g. The mixture was kept at 90° C. for 2 hours. The alkaline solution of methylsilanetriol was characterized as follows: alkalinity 3.2 mol / L, content 286 g / L, and solution density 1.19 kg / L. Gelling, washing, and washing control were performed according to the same parameters and criteria as in Example 1.

[0102] (Measurement results of supramolecular properties of PMSPH and parameters of some steps of the measurement method of supramolecular properties according to Example 2) 1. The weight of PMSPH was 21.39 g. The dry residue was 8.84%. The absorption capacity of methyl orange was 1.12 mg / g, and that of bovine serum albumin was 0.77 mg / g. 3. The estimated loading per PMSPG sample weight was 23.957 mg for methyl orange and 16.47 mg for bovine serum albumin. 4. The weight of the washed methyl orange was 0.5057 mg (2.11%). The weight of the washed bovine serum albumin was 0.2754 mg (1.67%). 5. The weight of the water poured was 171.12g. 6. The exposure time of the solution was 4 hours. 7. The weight of the washed methyl orange was 17.3233 mg (72.31%). The weight of the washed bovine serum albumin was 13.456 mg (81.7%). 10. The weight of the washed methyl orange was 5.0956 mg (21.27%). The weight of the washed bovine serum albumin was 2.426 mg (14.73%). The weight of the methyl orange remaining in the complex with PMSPG was 1.0324 mg (4.31%). The weight of the bovine serum albumin remaining in the complex with PMSPG was 0.3126 mg (1.90%).

[0103] Example 3: Preparation of polymethylsiloxane polyhydrate by conventional method and testing of supramolecular properties (embodiment using potassium hydroxide) 200 g of methylsilanetriol containing 90 g of PMS was mixed with 66.9 g of potassium hydroxide (main content 99.0%). The final MeOH / PMS ratio (mol / mol) was 0.88. After heating the mixture, 270 g of water was added. The total charge was 536.9 g. The mixture was kept at 90° C. for 2 hours. The alkaline solution of methylsilanetriol was characterized as follows: alkalinity 3.1 mol / L, content 323 g / L, and solution density 1.176 kg / L. Gelling, washing, and washing control were performed according to the same parameters and criteria as in Example 1.

[0104] (Measurement results of supramolecular properties of PMSPH and parameters of some steps of the measurement method of supramolecular properties according to Example 3) 1. The weight of PMSPH was 19.94 g. The dry residue was 10.13%. The absorption capacity of methyl orange was 1.38 mg / g and that of bovine serum albumin was 0.91 mg / g. 3. The estimated loading per PMSPG sample weight was 27.5172 mg for methyl orange and 18.1454 mg for bovine serum albumin. 4. The weight of the washed methyl orange was 0.8916 mg (3.24%). The weight of the washed bovine serum albumin was 0.3846 mg (2.12%). 5. The weight of the water poured was 159.52g. 6. The exposure time of the solution was 17 hours. 7. The weight of the washed methyl orange was 21.7881 mg (79.18%). The weight of the washed bovine serum albumin was 14.3221 mg (78.93%). 10. The weight of the washed methyl orange was 3.9267 mg (14.27%). The weight of the washed bovine serum albumin was 2.8434 mg (15.67%). The weight of the methyl orange remaining in the complex with PMSPG was 0.9108 mg (3.31%). The weight of the bovine serum albumin remaining in the complex with PMSPG was 0.5953 mg (3.28%).

[0105] As is evident from examples 2 and 3, most of the substances are washed off during the first acidification of the solution (step 7). The possible loading of marker substances on the PMSPH is much lower than in the product of the invention. It can therefore be concluded that the method of the invention for producing polymethylsiloxane polyhydrates makes it possible to produce products with new properties, which are obtained as a result of carrying out the method for producing the product according to the proposed and described sequence of steps.

[0106] (Examples 4-50: Method for manufacturing a structure using a mixture of an alkaline solution of methylsilanetriol and a chloride, sulfate, or carbonate of sodium or potassium) Considering the cheapness of sodium or potassium chlorides, sulfates, and carbonates, the authors carried out a series of experiments to investigate the supramolecular properties of polymethylsiloxane polyhydrates using various amounts of added electrolytes in the process of obtaining alkaline solutions of methylsilanetriol.

[0107] Gelling, washing, and washing control were performed according to the same parameters and criteria as in Example 1. The structures according to Examples 4 to 50 were obtained according to the method shown in Example 1. The main parameters and supramolecular properties using these electrolytes are shown in Table 2.

[0108] The data on the parameters of the supramolecular properties in the process determining the amount of washed out marker substances are not linearly correlated with the amount of added electrolyte in the process of producing an alkaline solution of methylsilanetriol. According to the authors, this dependence is multiparameter. According to the presented data, PMSPH has the ability to "conditionally confine" 74% to 85% of the marker substances and can release these substances if the acidity of the system is reduced. The above features are beneficial when utilizing the properties of this product in medical, veterinary and various industries.

[0109] (Examples 51 to 96: Methods for Producing Structures 51 to 96 Using Mixtures of Alkaline Solutions of Methylsilanetriol and Various Electrolytes) According to the method shown in Example 1, structures according to Examples 51 to 96 were obtained. The main parameters and supramolecular properties using these electrolytes are shown in Table 2. The absorption capacity values ​​of the samples obtained by the method of the present invention and described in the Examples are shown in Table 2.

[0110] The low molecular weight electrolytes in solution formed in the interstices of the hydrogel network react with the groups (OH (-) , OMe (-) , Me (+)) and increases the density of the electric double layer, which in turn reduces the diffusion of the solvent (an alkaline aqueous solution of methylsilanetriol) in the gel mass. This makes it easier for the polycondensation reaction to occur in the newly formed space without excessive entanglement of the three-dimensional coil, and the Me (+) This reduces the isolation of ions and allows reactions that replace OH groups with OMe groups (EV Vorobyeva, NP Krutko, "Polymer complexes in aqueous and saline environments", National Academy of Sciences of Belarus, Institute of General and Inorganic Chemistry, Minsk, Belaruskaya Navuka, 2010, 175 pp.)

[0111] The authors emphasize that the present invention has developed a new method for producing alkaline solutions of methylsilanetriol, which contain dimeric molecules and differ in their properties and behavior from the known potassium or sodium methylsiliconates.

[0112] [Table 2-1]

[0113] [Table 2-2]

[0114] [Table 2-3]

[0115] [Table 2-4]

[0116] [Table 2-5]

[0117] (General conclusions) The alkaline solution of methylsilanetriol prepared by the authors of the present invention is not described in the literature and has been experimentally proven not to belong to such substances as potassium methylsiliconate or sodium methylsiliconate. In the process of dissolving methylsilanetriol in alkali, only dimeric sets of molecules are formed at molar ratios of MeOH / PMS in the range of 0.84-0.9. A dimeric set of standard composition can be obtained from dehydrated methylsilanetriol. It has been established that in the process of polycondensation, the formation of low molecular weight fractions occurs, which "block" the final product. For this reason, it was also found that substitution reactions are less likely to occur. The addition of electrolytes to the alkaline solution of methylsilanetriol promotes the formation of PMSPH, which has supramolecular properties like a molecular capsule. In the process of producing PMSPH according to the described scheme, one of its characteristic properties is its absorption capacity, which also places the substance in question as an absorbent containing polymethylsiloxane polyhydrate. The structural formula of PMSPH is shown as a dimer of variable composition with a polyhydrate shell as the basic unit. The mass average molecular weight tends to be infinite.

Claims

1. 1. A method for producing polymethylsiloxane polyhydrates having supramolecular properties of a molecular capsule, the method comprising: mixing an alkali with a polymethylsiloxane contained in a methylsilanetriol at a temperature greater than 90° C. in a ratio of 0.84 to 0.9 moles of alkali per mole of polymethylsiloxane contained in the methylsilanetriol to provide a first mixture; adding 0.025 to 0.1 moles of electrolyte per mole of alkali to the first mixture to provide a second mixture; polycondensing the second mixture; The method according to claim 1, further comprising:

2. 2. The method of claim 1, wherein the electrolyte is a chloride, bromide, iodide, nitrate, nitrite, carbonate, sulfate, sulfite, acetate, oxalate, succinate, formate, citrate salt of lithium, sodium, potassium, ammonium, or mixtures thereof.

3. 2. The method of claim 1, wherein the alkali is sodium hydroxide or potassium hydroxide.

4. 2. A compound according to claim 1, comprising the following formula: 【Chemistry 1】 (In the formula, For products in the form of a gel, a range of q from 60 to 92 is typical; For products in the form of a paste, a range of q from 89 to 134 is typical; For products in the form of a suspension, a range of q from 133 to 241 is typical.

1. A polymethylsiloxane polyhydrate having supramolecular properties, characterized in that it has

5. An absorbent comprising the polymethylsiloxane polyhydrate of claim 4.

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