SU729203A1 - Method of preparing cross-linked polyvinylpyrrolidone - Google Patents

Description

The invention relates to methods for producing three-dimensional copolymers, which are used in gel chromatography and are the basis for the synthesis of ion exchangers. A known method of producing cross-linked polyvinylpyrrolidone in the presence of a cross-linking agent by co-balancing N-vinyl pyrrolidone and methylenebis-acrylamide in aqueous medium i. The aim of the invention is to obtain hydrolytically stable double and triple network copolymers based on N1-vinyl pyrrolidone, which are equally well swelling in water, polar and non-polar solvents and have a macroporous structure. This is achieved by carrying out N-vinylpyrrolidone copolymerisadium in the presence of diethylene glycol divinyl ether crosslinking agent. Using the diethylene glycol divinyl ether as the scavenging agent allows to obtain crosslinked copolymers that do not contain crosslinker blocks. Mesh copolymers are obtained by a radical mechanism in bulk and in the presence of an inert diluent (to produce macroporous copolymers). As an initiator, dinitrile of azozcomoic acid is used as an inert diluent — octane. The dependence of the degree of swelling on the ratio of components in the initial mixture for double and ternary copolymers is given in Table. 1 and 2.

Table 1

 N -vinylpyrrolidone The results are given in Table. 1 and 2 suggest that, by changing the ratio of the starting components, the degree of reticulation, and therefore the degree of swelling in various solvents, can be significantly changed. The degree of swelling of ternary copolymers can be changed by varying the ratio o87.1io, o bo, o 30.0 5O82.7 218.6 1О, 0 ЗО, 0 6О, О

two monomers N-vinyl pyrrolidone and styrene, not changed relative to diethylene glycol divinyl ether.

The dependence of the specific surface area and swelling of macroporous copolymers on the amount of cross-linking agent and diluent is given in table. 3. Table 3 2.97 7.21 6.91 3.68 8.91 8.24 These experimental data indicate that when using diethyleneglycol as the divinyl ether copolymer, it is possible to obtain copolymers of a macroporous structure and in the absence of an inert diluent, which cannot be achieved using well-known staplers. Copolymerization in a diluent results in copolymers with an even more developed surface. The specific surface of the copolymers is determined by a chromatographic method on a Chromo-4 chromatograph by measuring the heat conductivity of the sorbed polymer agent. Polymerase particles of size 25O-4OO µm were selected for measurements. Example 1. 2.2228 g of W -vinylpyrrolidone and 0.1663 g of di-ethylene glycol divinyl ether are placed in a vial containing O, O119 g of azo-isobutyric acid dinitrile (0.5% by weight of monomers), the vial is purged with nitrogen, sealed and incubated for 24 hours in a thermostat at a temperature of 6OiO. The resulting product is crushed and washed successively with petroleum ether with hot dichloroethane and dried in a vacuum to constant weight. The yield of crosslinked polymer is 2.1629 g, the degree of swelling: in water, 4.36; in acetone 3.17; in DMF 8.41; in benzene 6, O2 g per 1 g of dry polymer, Example 2: 1.6671 g of N-vinyl pyrrolidone, 0.5021 g of styrene and 0.7921 divinyl ether diethylene glycol are placed in a vial containing O, O147 g

Continued table. 3 dinitriles of azo isobutyric acid. The ampoule is flushed with nitrogen, sealed to a thermostat at 60 + 0 for 24 hours. The polymer that has developed is crushed, washed successively with petroleum ether, hot benzene and dichloroethane and dried under vacuum to constant weight. The yield of the crosslinked polymer is 2.3258 g, the degree of swelling: in water 2.0 in acetone 1.12; 3 DMF 5.42; in benzene, 4.96 g of dry polymer. Example 3. 0.5557 g of N-B1shylpyrrole {1 dona, 1.0422 g of styrene IO, 1312g of divinyl ester diethyl glycol are placed in a vial containing O, O114g of azoisobutyric acid dinitrile and 1.11 g of octane (5O weight,% of monomers ), Ampoule flushed with nitrogen, sealed to prevent the thermostat B. Polymerization is carried out with Er for 24 h at a television of 6O 0.5 C. The resulting copolymer, the grind 4aK5Tj, is washed with hot benzene, lorethan and dried in vacuum to constant weight. The yield of the net copolymer is 1.8433 g, i.e. 82.7%, swelling in water 3.68, in acetone 3.12 „in DMFA8.91, in benzene 8.24 g on an ircVxc gel, specific surface area 218.6 m / g. All copolymers based on KJ-vinyl-pyrrolitone are stable during boiling in aqueous and alcoholic solutions and cause prolonged heating in solutions of acids and alkalis in the pH range 4–9. The proposed network copolymers have well varied degree of swelling

in various solvents. Triple reticulated copolymers containing f-vinyl pyrrolidone and styrene units can serve as a basis for the synthesis of polyfunctional ionites by carrying out the corresponding transformations along the lactam cycle and the benzene ring.

Of great practical importance is also the high adsorptive capacity and tendency to form a complex of linear polyvinscrrolidone. Polyvinylpyrrolidone absorbs or forms a complex with various compounds {dyes, drugs, toxins, etc.). Such features of polyvinylpyrrolidone open up wide possibilities for its use in crosslinked standing, since In addition to purely gel-chromatographic properties, the proposed copolymers will have sorption and complex-forming properties.

F o rm ula invention

Claims (1)

1. A method for preparing a crosslinked polyvinylpyrrolidone by radical copolymerization of N-vinylidpyrrolidone in the presence of a crosslinking agent, characterized in that, in order to obtain a hydrolytically stable network copolymer with a well-controlled degree of swelling in various solvents, divinyl ether of ethylene glycol is used as a crosslinking agent 2, a method according to claim 1, characterized in that the copolymerization is carried out in the presence of styrene. Sources of information taken into account in the examination; 1. and. J. lea h. 9r. Saul, J. Siet. 40, 159, 1962 (prototype),.