RU2757596C1 - Dimethyl ether of 4-chlorophthalic acid as polymer plasticiser - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to an application of dimethyl ether of 4-chlorophthalic acid by the formula

as a polyvinyl chloride plasticiser.

EFFECT: invention provides a possibility of producing polymers and composites with increased levels of fire, heat and thermal resistance, preserving good dielectric properties in a wide range of temperatures and frequencies, easily soluble in standard organic solvents, and recyclable into products by standard technological methods.

1 cl, 1 tbl, 6 ex

Description

The invention relates to new chemical compounds, namely to chlorine-containing dimethyl ester of phthalic acid, which can be used as a plasticizer for polymers, an intermediate for the synthesis of monomers used to produce polymers, in particular polyimides.

The invention relates to a new chemical compound, specifically to di (1,2-methylcarboxylate) 4-chloro-benzene:

exhibiting plasticizing properties, as well as a monomer with reactive end groups, entering into polymer synthesis reactions.

Known dialkyl esters of phthalic acid, and methods for their preparation, which are used as plasticizers of various polymers:

1. Handbook of chemist 21 pages 671. Chemistry and chemical technology.

https://www.chem21.info/page/002204213213070044112171038177108225007175230096/

2. Pat. RF No. 2064923. A method of producing polyvinyl chloride plasticizers. Publ. 08/10/1996

3. Pat. RF No. 2158729. A method of obtaining diethyl ester of phthalic acid. Publ. 10.11.2000

4. Knunyants I.L. Chemical encyclopedia in 5 volumes. - Soviet encyclopedia. 1988 S. 1116-1118.

It was not possible to find a description and method for preparing 4-chlorophthalic acid dimethyl ester in the available literature.

Closer to the proposed structure and properties (analogue) is Auth. wit. USSR No. 525662. Chlorine-containing esters of carboxylic acids exhibiting plasticizing properties. Publ. 08/25/76. Bull. No. 31.

According to the inventor's certificate, the following compounds are offered:

where R is alkyl, phenyl, exhibiting a plasticizing effect with respect to polyvinyl chloride. The disadvantages of these monomers are insufficiently high values of thermal stability and mechanical properties of plasticized polymer composites obtained on their basis.

The objective of the invention is to expand the range of organic compounds exhibiting plasticizing properties, as well as monomers with reactive end groups that enter into polymer synthesis reactions.

The problem is solved by obtaining a new chlorine-containing dimethyl ether - di (1,2-methylcarboxylate) 4-chlorobenzene by the interaction of 4-chlorophthalic anhydride (4-CPA) with methanol in the presence of sulfuric acid.

The invention is illustrated by the following examples.

Example 1.

In a three-necked flask equipped with a stirrer, thermometer and reflux condenser, load 36.512 g (0.2 mol) of 4-chlorophthalic angyride, 81 ml of methanol (2 mol), 0.1 g of concentrated sulfuric acid (ρ = 1.84 g / ml ). The molar ratio of 4-CPA: methanol is 1:10. Stirring is turned on and, having increased the temperature to 50 ° C, the esterification reaction is carried out for 30 minutes, then the temperature is increased to 60 ° C, and the reaction mixture is maintained for 60 minutes. After that, the contents of the flask are heated to 75 ° C in a water bath, the stirrer is removed, and the excess of methyl alcohol is distilled off. The contents of the flask — an oily liquid — is diluted with 50 ml of chloroform and washed with a solution of sodium bicarbonate in distilled water until the wash water is neutral with phenolphthalein. After that, carry out the distillation of chloroform at a temperature of 75 ° C water bath. 38.87 g (85%) of a light yellow liquid - di (1,2-methylcarboxylate) 4-chlorobenzene are obtained.

From the results of elemental analysis, functional analysis, thin layer chromatography, IR spectroscopy, 4-chlorophthalic acid dimethyl ester of the formula is formed:

Calculated molecular weight of the product = 228.6317 g / mol; elemental composition,%: C = 52.53 / 51.66; H = 3.97 / 3.59; O = 27.99 / 28.24; Сl = 15.51 / 15.36 (calculated in the numerator, found in the denominator).

The IR spectra revealed absorption bands in the region, cm ^-1 : 1090-1072 (C _arom -Cl); (stretching vibrations -C = O of the ester group); 1280-1050 (stretching vibrations of the ether -C-O-C- bond).

Example 2.

According to example 1, only the amount of methanol in the reaction mixture is 89 ml (2.2 mol). The molar ratio of 4-CPA: methanol is 1:11. The reaction product yield is 39.85 g (87.2%).

Example 3.

According to example 1, only the amount of methanol in the reaction mixture is 97 ml (2.4 mol). The molar ratio of 4-CPA: methanol is 1:12. The reaction product yield is 41.34 g (90.4%).

Example 4.

In example 1, only the amount of methanol in the reaction mixture is 101 g (2.5 mol). The molar ratio of 4-CPA: methanol is 1: 12.5. The yield of the reaction product is 42 g (92%).

Example 5.

In example 1, only the amount of methanol in the reaction mixture is 105 ml (2.6 mol). The molar ratio of 4-CPA: methanol is 1:13. The yield of the reaction product is 42.3 g (92.5%).

Example 6.

In example 1, only the amount of methanol in the reaction mixture is 113.5 ml (2.8 mol). The molar ratio of 4-CPA: methanol is 1:14. The yield of the reaction product is 42.7 g (93.3%).

The synthesized 4-chlorophthalic acid dimethyl ester exhibits a plasticizing effect with respect to polymers, and can also be used as a monomer with reactive end groups, which enters into polymer synthesis reactions.

The proposed connection has a liquid state of aggregation, which makes it possible to obtain on its basis potting compounds, plasticizers with increased fire resistance and other important performance characteristics.

The table shows some properties of polyvinyl chloride, plasticized synthesized according to example 5 dimethyl ester of 4-chlorophthalic acid and an analogue.

table

Composite Properties of plasticized polyvinyl chloride ε,% σ _res., kgf / cm ² T _2%, ° C Following example 5 220-240 380-460 210-280 Analogue 210-230 190-220 200-260

σ _res. - tensile breaking stress;

ε - elongation at break.

With the applied use of 4-chlorophthalic acid dimethyl ester, polymers and composites with increased values of fire, heat and heat resistance are obtained, retaining good dielectric properties in a wide range of temperatures and frequencies, are easily soluble in common organic solvents, and can be processed into articles by conventional technological methods.

The technical result is to expand the range of organic compounds exhibiting plasticizing properties, as well as monomers with reactive end groups that enter into polymer synthesis reactions.

Claims (2)

The use of 4-chlorophthalic acid dimethyl ester of the formula

as a plasticizer for polyvinyl chloride.