RU2645551C2 - Method for synthesis of hydrogels based on polyhexamethyleneguanidine hydrochloride - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method for production of a polyhexamethyleneguanidine hydrochloride gel is implemented using aldehydes as the cross-linking agent of the polymer end groups at mixing of an aqueous solution of polyhexamethyleneguanidine hydrochloride at a concentration of 25 wt % with an amount of formaldehyde equivalent to the amount of the amino end groups of polyhexamethyleneguanidine hydrochloride at a room temperature followed by washing with distilled water for aldehyde residues removal.

EFFECT: simplification and acceleration of polyhexamethyleneguanidine hydrochloride gelling process with increased yield of hydrogel.

5 ex

Description

The invention relates to the field of gel synthesis based on polyhexamethylene guanidine hydrochloride and can be used to obtain water-swellable hydrogels as the basis for new dosage forms.

Known [Vointseva I.I., Gembitsky P.A. Polyguanidines - disinfectants and multifunctional additives in composite materials. M .: LKM-press, 2009, p. 304] a method for producing hydrogels based on polyhexamethylene guanidine hydrochloride by polycondensation of hexamethylene diamine and guanidine hydrochloride at a temperature of 165 ° C for 10 hours

The disadvantages of this method are the low hydrogel yield, up to 45% of the load, as well as the long duration of the process.

The prototype of the claimed invention is a patent of the Russian Federation 2394110, relating to a method for producing a polymer gel sorbent for the gold mining industry. The method involves dissolving polyhexamethylene guanidine hydrochloride in an aqueous ammonia solution to which phenols are added and formalin is added in portions. Then it is heated to boiling temperature for 1-5 hours. The emulsion formed throughout the volume is poured into an aqueous alkaline solution. In this case, the precipitated resin is washed from alkali and dried. The technical result is to obtain a water-insoluble polyhexamethylene guanidine (gel form) used in the production of gold.

The disadvantage of this method is that in the process of obtaining a water-insoluble form of polyhexamethylene guanidine, using phenol and formaldehyde, phenol-formaldehyde resin is formed, while polyhexamethylene guanidine itself partially interacts with formaldehyde, forming a water-insoluble form. However, the yields of the target product in gel form are not significant.

An object of the invention is to simplify the gelation process of polyhexamethylene guanidine hydrochloride and increase the yield of the product.

The technical result of the invention is carried out by obtaining a branched-chain polyhexamethylene guanidine hydrochloride as a result of the interaction of hexamethylene diamine and guanidine hydrochloride in a molar ratio of 1.4 to 1, respectively, at a temperature of 165 ° C for 3 hours and further mixing of aqueous solutions of polyhexamethylene guanidine hydrochloride with a concentration of 25 wt. % with the number of amino groups 0.03 mol and medium viscosity molecular weight 5000 and a formaldehyde solution concentration of 10% to obtain a gel at room temperature with further washing with distilled water to remove residual aldehyde.

The essence of the proposed technical solution is illustrated by the following examples.

Example 1

100 ml of a polymer solution containing polyhexamethylene guanidine hydrochloride concentration of 15 wt. % with an amount of amino groups of 0.03 mol and a viscosity average molecular weight of 5000 was placed in a glass beaker, 10 ml of a 10% formaldehyde solution with an amount of aldehyde equivalent to the number of terminal amino groups of the polymer was added, and stirred until a gel-like mass was obtained. The resulting gel was transferred to a Buchner funnel, followed by repeated washing with water and drying at 40 ° C for 1 hour. The hydrogel yield was 50%.

Example 2

100 ml of a polymer solution containing polyhexamethylene guanidine hydrochloride concentration of 20 wt. % with an amount of amino groups of 0.03 mol and a medium viscosity molecular weight of 5000 was placed in a glass beaker, 14 ml of 10% formaldehyde solution with an amount of aldehyde equivalent to the number of terminal amino groups of the polymer was added, and stirred until a gel-like mass was obtained. The resulting gel was transferred to a Buchner funnel, followed by repeated washing with water and drying at 40 ° C for 1 hour. The hydrogel yield was 58%.

Example 3

100 ml of a polymer solution containing polyhexamethylene guanidine hydrochloride concentration of 25 wt. % with an amount of amino groups of 0.03 mol and a medium viscosity molecular weight of 5000 was placed in a glass beaker, 17 ml of 10% formaldehyde solution with an amount of aldehyde equivalent to the number of terminal amino groups of the polymer was added, and mixed until a gel-like mass was obtained. The resulting gel was transferred to a Buchner funnel, followed by repeated washing with water and drying at 40 ° C for 1 hour. The hydrogel yield was 65%.

Example 4

100 ml of a polymer solution containing polyhexamethylene guanidine hydrochloride concentration of 25 wt. % with an amount of amino groups of 0.03 mol and a medium viscosity molecular weight of 5000 was placed in a glass beaker, 35 ml of a 10% formaldehyde solution with an amount of aldehyde twice the amount of terminal amino groups of the polymer was added, and mixed until a gel-like mass was obtained. The resulting gel was transferred to a Buchner funnel, followed by repeated washing with water and drying at 40 ° C for 1 hour. The hydrogel yield was 75%.

Example 5

100 ml of a polymer solution containing polyhexamethylene guanidine hydrochloride concentration of 25 wt. % with the number of amino groups 0.03 mol and medium viscosity molecular weight 5000, placed in a glass beaker, 86 ml of 10% formaldehyde solution with the amount of aldehyde equivalent to the number of terminal amino groups of the polymer was added, and mixed until a gel-like mass was obtained. The resulting gel was transferred to a Buchner funnel, followed by repeated washing with water and drying at 40 ° C for 1 hour. The hydrogel yield was 62%.

Thus, the optimal yield of the gel is method 4.

The resulting gels in dry form represent granules (powders) that do not dissolve in water and organic solvents, but multiply in volume when water is added.

The present invention can be used as a method for producing hydrogels based on polyhexamethylene guanidine hydrochloride.

It should be noted that testing gels for the presence of antimicrobial activity completely suppresses the vital activity of microorganisms (E. coli, B. cereus) in a nutrient medium.

Claims (1)

The method of synthesis of hydrogels based on polyhexamethylene guanidine hydrochloride is carried out by mixing 100 ml of an aqueous solution of polyhexamethylene guanidine hydrochloride concentration of 25 wt. % with the amount of aldehyde equivalent to the number of terminal amino groups of polyhexamethylene guanidine hydrochloride to obtain a gel at room temperature with further washing with distilled water to remove residual aldehyde.