RU2394847C2 - Polyester-ketone synthesis method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing high-molecular compounds, particularly methods of producing aromatic polyesters through high-temperature polycondensation. Aromatic polyester-ketones are obtained by reacting dioxy-compounds with potassium hydroxide and distillation of an azeotropic mixture of water and chlorobenzene. At the first step synthesis is carried out between phenolate and 4,4'-dichlorobenzophenone for 3 hours at 220-250°C in diphenylsulfone. At the second step, synthesis is carried out between oligoketone with condensation degree n=20 and 4,4'-difluorobenzophenone for 6 hours at 250-270°C in an inert medium.

EFFECT: invention reduces cost of aromatic polyester-ketones by more than 10 times due to use of relatively cheap 4,4'-dichlorobenzophenone.

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Description

The invention relates to methods for producing high molecular weight compounds, in particular to methods for producing polyesters by high temperature polycondensation.

Known methods for producing polyesters by high temperature polycondensation in high boiling solvents at 200-350 ° C for 12-36 hours. The disadvantages of these methods are harsh conditions, low molecular weight values and, as a consequence, low physical and mechanical properties [1-5].

The synthesis of polyetherketones based on cheap 4,4'-dichlorobenzophenone does not allow the production of high molecular weight polyetherketones.

The closest analogous method can be the preparation of polyether ketones [6], from which it is known that polyether ketones are obtained by reacting 4,4'-difluorobenzophenone with potassium diphenolate of 2,2-bis (4-hydroxyphenyl) propane in N, N-dimethylacetamide. The disadvantage of this production method is that high molecular weight polyether ketones are obtained only from 4,4'-difluorobenzophenone, which increases the price of polyether ketones obtained by this method up to 20 times or more in comparison with other polyesters of the same purpose.

The objective of the invention is to reduce the cost of high molecular weight polyetherketone by cheapening the method of obtaining them from the cheap monomer 4,4'-dichlorobenzophenone using a small amount of expensive 4,4'-difluorobenzophenone.

The problem is solved by the production of polyetherketones by the interaction of dioxo compounds of various structures with dihalogenobenzophenones.

The essence is that dioxo compounds are converted into dipotassium salt by the action of an alkali solution, water and chlorobenzene are distilled off at a temperature of 130-140 ° С and the synthesis is carried out in two stages: at the first stage, the synthesis is carried out between phenolate and 4,4'-dichlorobenzophenone for 3 hours at 220-250 ° C in diphenylsulfone, and in the second stage, the synthesis is carried out between the formed oligoketone and 4,4'-difluorobenzophenone at 250-270 ° C for 6 hours in an inert gas medium.

Example 1. The synthesis of polyetherketone based on 2,2-bis (4-hydroxyphenyl) propane.

4.5687 g (0.02 mol) of 2,2-bis (4-hydroxyphenyl) propane, 55 g of diphenyl sulfone, 40 ml of chlorobenzene are added to a three-necked conical flask equipped with a stirrer, a reflux condenser with a Dean-Stark trap, a bubbler and a thermometer. and with heating and stirring, 1.6 g (0.04 mol) of KOH are added. In a stream of nitrogen at a temperature of 130-140 ° C, water with chlorobenzene is distilled off. After the water and chlorobenzene are completely distilled off, 4.78311 g (0.019) of 4,4'-dichlorobenzophenone is introduced into the reaction flask and the reaction is carried out at 220-250 ° C for 3 hours.

In the second stage of the reaction, 0.20782 g (0.001 mol) of 4,4'-difluorobenzophenone is added and the reaction is continued for 6 hours at 250-270 ° C. The reaction mass is cooled, diluted with 40 ml of chloroform, precipitated in isopropyl alcohol and washed ten times with hot distilled water and five times with hot isopropanol.

Polyetherketone is a light brown powder. The yield is 96%. η _ol = 0.8 dl / g

Example 2. Synthesis of polyetherketone based on 3,3-di (4-hydroxyphenyl) phthalide.

6.3666 g (0.02 mol) of 3,3-di (4-hydroxyphenyl) phthalide, 55 g of diphenyl sulfone, 40 ml of chlorobenzene are added to a three-necked conical flask equipped with a stirrer, a reflux condenser with a Dean-Stark trap, a bubbler and a thermometer. and with heating and stirring, 1.6 g (0.04 mol) of KOH are added. In a stream of nitrogen at a temperature of 130-140 ° C, water with chlorobenzene is distilled off. After the water and chlorobenzene are completely distilled off, 4.78311 g (0.019) of 4,4'-dichlorobenzophenone is introduced into the reaction flask and the reaction is carried out at 220-250 ° C for 3 hours.

In the second stage of the reaction, 0.20782 g (0.001 mol) of 4,4'-difluorobenzophenone is added and the reaction is continued for 6 hours at 250-270 ° C. The reaction mass is cooled, diluted with 40 ml of chloroform, precipitated in isopropyl alcohol and washed ten times with hot distilled water and five times with hot isopropanol.

Polyetherketone is a light brown powder. The yield is 95.7%. η _ol = 0.67 dl / g.

Various bisphenols can be used as dioxo compounds: halogen-substituted 2,2-bis (4-hydroxyphenyl) propane, 4,4-dioxo-3,3-dimethyl-2,2-diphenylpropane, 2,2-bis (4-hydroxyphenyl) -2-phenylethane, 9,9-bis (4-hydroxyphenyl) fluorene, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenyl oxide, 4,4'-dihydroxybiphenyl, dichlorodiphenyl-cyclohexane.

The technical result of the invention is to reduce the cost of polyetherketone through the use of cheaper 4,4'-dichlorobenzophenone instead of 4,4'-difluorobenzophenone.

Literature

1. Application 3700808 (Germany). A method of obtaining a polyaryletherketone.

2. Shaov A.Kh., Kharaev A.M., Mikitaev A.K. and others. Aromatic polyether ketones and polyether ether ketones. // Plastics, 1990, No. 11. S.14-17.

3. Application 61-176627 (Japan). Aromatic simple polyetherketones and method for their preparation.

4. Application 3836582 (Germany). A method of producing polyarylene ether sulfones and polyarylene ether ketones.

5. Application 3901072 (Germany). A method of producing polyarylene ether ketones.

6. Shaposhnikova V.V., Salazkin S.N., Sergeev V.A. et al. Regularities of the reaction of 4,4'-difluorobenzophenone with potassium diphenolate of 2,2-bis (4-hydroxyphenyl) propane. Izv. AN Ser. Chemical, 1996, No. 10. S.2526-2530.

Claims (1)

A method for producing polyetherketones based on dioxo compounds of various structures and dihalogenobenzophenones, comprising reacting dioxo compounds with potassium hydroxide, distilling off an azeotropic water-chlorobenzene mixture, characterized in that the synthesis is carried out in two stages: in the first stage, the synthesis is carried out between phenolate and 4,4'-dichlorobenzophenone for 3 hours at 220-250 ° C in diphenyl sulfone, and in the second stage, the synthesis is carried out between the resulting oligoketone and 4,4'-difluorobenzophenone for 6 hours at 250-270 ° C in an inert gas.