SU891689A1 - Method of preparing polymers and copolymers of n-vinylamidosuccinic acid - Google Patents

Description

The invention relates to the chemistry of high-molecular compounds, in particular to the preparation of poly-and copolymers of N-vinyl amido succinic acid (WACA), and can be used in the synthesis of polymer matrices of drug prolongators as well as selective sorbents of heavy metal ions. A known method for the preparation of polyacid and copolymers of BACA consists in the polymerization of N-vinylsuccinimide (her) in a solvent (benzene, ethyl alcohol, dichloroethane), and the products are purified by repeated reprecipitation - and dried under vacuum, followed by alkaline hydrolysis with an aqueous solution of NaOH and transfer of the alkaline form to the acid by ion exchange 1. The disadvantage of this method is the complexity of its implementation, due to its duration, the laboriousness of the isolation and purification of intermediate products, the high consumption of organic solvents. The closest to the proposed technical essence is the method of obtaining poly-and copolymers of N-vinyl amide acid with radical polymerization or copolymerization of N-vinylsuccinimide with vinyl monomers (with vinyl acetate) in an organic solvent (dichloroethane), in the presence of radical initiation torus (benzoyl peroxide, 0.3 May.%) when heated (65 ° C, 8 h), followed by hydrolysis of the resulting poly- and copolymers in the presence of an aqueous alkali solution and conversion of the formed salts into ionic form by ion exchange. In this method, the intermediates of the polymerization reaction (copolymers of VSI and viniladetate) are separated by precipitation into diethyl ether and purified by re-precipitating from solutions in chloroform to petroleum ether, followed by drying under vacuum to constant weight. Heterogeneous alkaline hydrolysis of the copolymers is carried out with a 5% NaOH solution at 60 ° C for 6 hours. The cooled reaction mass is then passed through a column containing the cation exchange resin KU-2 in the hydrogen form. The eluate (a solution of copolymer VSI and vinyl alcohol) is concentrated by distillation of water in vacuum, precipitated in acetone, washed repeatedly with acetone

and dried at 20 ° C to constant weight. The product is a white powder, yield less than 66S 2.

However, this method is also technologically difficult, due to the lengthy, laborious nature of the extraction and purification of promezh-. accurate products, - hydrolysis for a long time - at elevated temperatures, consumption of a significant amount of solvents.

The purpose of the invention is to simplify the method.

The goal is achieved by the fact that according to the method of producing poly-and copolymers of N-vinyl amido succinic acid by radical polymerization or copolymerization of N vinylsuccinimide with vinyl monomers in an organic solvent in the presence of a radical initiator during heating and subsequent hydrolysis of the resulting poly and copolymers in the presence of an aqueous solution alkali and transfer to the acid form of the resulting salts by ion exchange as an organic solvent, use dimethyl sulfoxide (DMSO) copolymerization is carried out at a monomer concentration of 0,25-3,5 mol / l, and the hydrolysis is carried out at a molar ratio of alkali, and poly- or copolymer is equal to (1,011, 10):. 1, and the temperature 20-25 ° C.

Conducting poly- and copolymerization at a concentration of HSI in MDSO above 3.5 mol / l or below 0.25 mol reduces the speed of the process and decreases the yield of the product.

The amount of initiator is 0, 30% relative to the Monomers, which provides the necessary molecular weight of the polymers obtained, suitable for medical purposes and sufficient (CO) polymerization rate.

The stage of hydrolysis of the wire is that with the use of 1-5%. NaOH solutions. In more concentrated solutions, further hydrolysis of the amide bond is observed with the formation of amino groups.

The proposed method eliminates the stages of isolation and purification of intermediates, speeds up the (co) copolymerization and alkaline hydrolysis steps, reduces the hydrolysis temperature to room temperature and simplifies the copolymerization step by simultaneously loading monomers in the case of obtaining VACN copolymers, moreover, significantly reduce organic consumption. solvents.

This positive effect is achieved through the use of dimethyl sulfoxide (DMSO). DMSO performs the functions of molecular weight and dilution regulator (CO) of the VSI polymers in the first stage of syn-.

In this case, the activity regulator of monomers is used in the case of obtaining VSII copolymers with vinyl monomers, as a result of which monomers can be simultaneously loaded in the case of the preparation of VACN copolymers, the hydrolysis catalyst (CO) of VSI polymers.

Solutions of (CO) polymers of CSI in DMSO form homogeneous reaction masses with added alkali solutions, therefore the hydrolysis process is very homogeneous from the very beginning, while providing the conditions for the fastest and most complete decomposition of BSI with the formation of the NAJA Na-salt units.

The method is carried out as follows.

CSI is dissolved in DMSO at a concentration of 0.25-3.5 mol / L. Vinyl acetate, hydroxyethyl methacrylate, etc. are added thereto when preparing copolymers with vinyl monomergly. The initiator (dinitrylazo-isobutyric acid, etc.) is introduced in an amount of -0.1-0.3 May. % to monomer. The reaction mass is purged with nitrogen, the stage (CO) of polymerization is carried out at bO-C 0 during 30 180 minutes.

In the resulting solution (CO) polymer. VSI-in DMSO in a solution of a 1-5% aqueous solution of caustic soda in a quantity of 1.05-1.10 mol per 1 mol of polymer and hydrolysis is carried out without heating at room temperature (20-25 C) for 30 -60. minutes to obtain a BACA salt or a copolymer of On-salt BAYA with vinyl monomers. Then the reaction mass is poured into a 10-fold excess of acetone, the polymer precipitate is filtered, the solution is dissolved in water and converted into acid form by ion exchange 2, or by high-voltage electrodialysis. The polymer POMNAK or BACA copolymers with vinyl 4 num- ples are isolated from aqueous solutions of chromium in acetone or freeze-dried.

Example 1. The process of producing poly-N-vinyl amido succinic acid. (PUCC) is carried out - according to the following recipe, mac. :

I-Binylescini w,. 10.0

Dinitrile azo-butyric acid; 0.015

Dimethyl sulfoxide 150

2% aqueous solution of caustic soda 165.

A three-tube flask placed in a thermostat () and equipped with a stirrer and a hydraulic shutter, a reflux condenser and a device for introducing nitrogen in an inert current of gas, is charged with a solution of the VSI monomer and the DAK initiator 15. DMSO (VSI concentration, -3.5 mol / l) -. After 1 hour, the flow of nitrogen into the flask is stopped and the heating thermostat is switched off. 135 ml.u. DMSO and an aqueous solution of caustic soda are charged to the reaction flask (Hydrolysis is carried out for 1 hour while stirring. The solution of the hydrolyzed polymer is precipitated 10-fold acetone, the precipitated precipitate of NACOL is filtered, dissolved in water, and a 2% solution is passed through a column filled with cation exchange resin KU-2. The resulting aqueous solution of PUAC is lyophilized.

The yield of the PUAC is 72%.

Calculated,%: N 9.78.

Found,%: M 9.69 9.67.

The molecular weight is 820,000.

Example 2 .. The process of preparing the PUCC is carried out according to the following recipe, wt.h .;

N-Vinylsucimide 3/1

Dinitrile-azo-isomasna

acid0,010

Dimethyl sulfoxide 97.0

2% aqueous solution

caustic soda 60,0

The process is carried out analogously to example 1, but the polymerization of the ALL is carried out in 97 wt.h. DMSO (concentration of ALLS O, 25 mol / l). To carry out the hydrolysis, only caustic soda solution is introduced into the solution of the obtained PVA, not. enter an additional amount of DMSO.

The yield of the PUAC is 66%, the molecular weight is 250,000.

Example 3. The process of producing the PUCCN Na-salt is similar to Example 1, but its conversion into acid form is carried out using high-voltage electrodialysis. The PUaca Na salt is placed in the middle chamber of the electrodialyzer, distilled water is added and stirred throughout the process. The side chambers are filled accordingly: anodic 0.05 n. solution of sulfuric acid, cathodic - 0.05 n. sodium hydroxide solution. The supplied voltage is gradually increased from 50 to 1000 V. The process of electrodialysis is carried out until a minimum value of 20 ml is established, which does not change in magnitude for 1 hour, constant acid number — the contents of the middle chamber, indicating a complete transfer of the salt form of the polymer in acidic. The bromine number of the solution in the anode chamber should be zero. A membrane film is used as a membrane, or, in order to accelerate the process of electrodialysis and reduce the applied voltage to 550 V, an anion-exchange membrane of the MA-40 brand and a cation-membrane membrane of the MK-40 brand are used as the membrane.

The yield of the PUAC is 79%.

Example 4. The process for the preparation of a BACA copolymer with 2-hydroxyethylmethineate (OMEM) is carried out according to the following formulation, wt.h .:

N-Vinylsuccinimide 7.5 2-Oxyethylmethacrylate 2.5 Dinitrile azoisobutyric acid0.015

Dimethyl sulfoxide 150 with 2% aqueous solution

caustic soda165

The process is carried out similarly to the example. 1, but when carrying out the copolymerization using a solution of monomers in 60 ml of DMSO, the duration of a coin

polymerization for 3 hours, and then to conduct the hydrolysis, 90 MP DMSO and caustic soda solution are introduced into the solution of the obtained VSI – OEMA copolymer; 5 The yield of the BACA copolymer is 62%.

Example 5. The process for the preparation of a BACA copolymer with vinyl acetate (BA) is carried out according to the following formulation, May. including:

N-Vinyl succinimide 5, o Vinyl acetate 5,0

Azoisobutyric acid dinitrile .020 5 Dimethyl sulfoxide. 90 A 5% aqueous solution of caustic soda 85 The process is carried out in analogy with example 1, but during the copolymerization, a solution of monomers in 90 ml of DISO is used, the copolymerization takes 3 hours, and then a solution of caustic soda is introduced into the copolymer solution, the duration of the hydrolysis is 2 h. The yield of the BACK – VC copolymer is 65%.

Examples 6-8 are wires that are negative for proving the required process parameters. 0 Example 6. The stage of obtaining the PVS is performed in the same way as in Example -1, but with a concentration of CSI and DMSO 4, O-mol / L.

As a result of the polymerization, a swollen PVSI gel is formed which is insoluble in organic solvents, with limited applications.

Example 7. The step of preparing the PVSI is carried out analogously to Example 1, Q, but with a HSI concentration in DMSO of 0.20 mol / L.

The polymerization proceeds slowly and the conversion over 76 hours is 76%.

Example 8. The stage of hydrolysis of PVSI is carried out analogously to example 1 /

5 but with a caustic soda concentration of 5%. After 10 minutes, the product darkens, data analysis shows the presence of amino groups in the copolymer.

As a result of the implementation of the proposed method of obtaining (CO) B.NAK copolymer, the corresponding products were obtained in high yield, displacing a practically 100% degree of conversion of the VSI units to acidic 5 groups.

When implementing the method, significantly / fewer organic solvents are consumed and a small amount of waste is generated. A comparative analysis of the known methods for producing (co) polymers: WACA and the proposed one shows the presence of advantages, c. polymerisation stages are higher process speed, less solvent consumption,. since the process is carried out in more concentrated pacTBOpcix. In addition, the introduction of chain carriers is not required; simultaneous loading of monomers is possible at. copolymerisation. The hydrolysis step can be carried out - isolation bases and. pre-purification of (CO) -polymers from the impurities of the reaction medium and without heating (at room temperature).

Claims (2)

1.Nikolaev A.F. et al. Preparation and properties of plly-N -vinylsuccionic acid. - High-molecular compounds, 1964, vol. 6, no. 2, p. 292-296. 2.Nikolaev A.F. and other. Viscometric study of aqueous solutions of a copolymer of vinyl alcohol and N-vinyl amide of ntadic acid. 5 Lime universities. Chemistry and Chemical Technology, 1973, Vol. 16, O 11, with. 1732-1735 (prototype).