RU2284318C1 - 4-(2,3-epoxypropoxy)-4'-propyloxyazobenzene eliciting property of light-thermostabilizing agent for polyvinyl chloride - Google Patents

Abstract

FIELD: chemical industry, chemical technology.

SUBSTANCE: invention relates to synthesis of 4-(2,3-epoxypropoxy)-4'-propyloxyazobenzene eliciting properties of light-thermostabilizing agent for polyvinyl chloride.

EFFECT: valuable properties of compound.

2 tbl, 1 ex

Description

Introduction

The invention relates to the chemical industry, in particular to the production of epoxy-containing azobenzenes, in particular 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene, which can be used as a light and thermal stabilizer of polyvinyl chloride (PVC).

State of the art

It is known that epoxy compounds containing a three-membered heterocyclic oxirane ring in a molecule are used as PVC light stabilizers [I. Voigt. Stabilization of synthetic polymers against the effects of light and heat. L .: Chemistry, 1972. 544 p.]. It can be epoxidized hydrocarbons, simple and complex epoxyesters, epoxies.

The closest structural analogue of the claimed compounds is the epoxy resin ED-20. This is a fairly effective light stabilizer. However, it does not exhibit a thermostabilizing effect and is used in a mixture with salts of organic acids (calcium, barium or cadmium stearate), which complicates and increases the cost of the material and increases its toxicity when using cadmium compounds.

SUMMARY OF THE INVENTION

The inventive task was to find a new derivative of epoxy-containing azobenzene, which simultaneously exhibits the properties of both light and heat stabilizer of PVC and does not require the presence of salts of organic acids.

The problem is solved by the compound 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene:

The structure of the claimed compounds is proved by methods of elemental analysis and NMR spectroscopy ¹ H and ¹³ C.

¹ H 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene NMR spectrum in chloroform-D shows resonant signals of aromatic protons (chemical shifts in ppm relative to HMDS are given) 7.84 and 7.75 d (4H) ; 6.98 and 6.89d (4H); propyloxy groups 0.98t (3H); 1.78 d (2H); 3.92 t (2H); epoxy groups 4.18d (1H); 3.31t (1H); 2.84 and 2.72 t (2H).

In the ¹³ C 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene NMR spectrum, signals of carbon atoms of benzene rings are observed (chemical shifts in ppm relative to HMDS are shown) 161.3; 115.1; 123.8; 148.5; 147.9; 115.0; 123.6; 159.9; carbon atoms of the epoxy group 69.9; 51.0; 44.5; carbon atoms of an alkoxyl chain 8.4; 22.1; 70.0.

The use of the claimed compounds as a light and thermal stabilizer of PVC allows to provide higher characteristics of the polymeric material in terms of strength properties and especially in elasticity, and also to exclude the use of salts of organic acids.

Information confirming the reproducibility of the invention

The following substances were used for the synthesis of 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene:

1.4-nitrophenol TU 6-09-3973-75

2. Iodine propyl TU 6-09-08-1204-77

3. Potash GOST 4221-76

4. Dimethylformamide TU 6-09-3720-79

5. Phenol GOST 23519-93

6. Sodium nitrite GOST 19906-74

7. Epichlorohydrin GOST 12844-74

8. Hydrochloric acid GOST 857-95

9. Sodium hydroxide GOST 11078-78

10. Sodium sulfate GOST 6318-77

11. Ethanol GOST 10749.3-80

The claimed compound was prepared as follows.

Stage 1. A mixture of 13.9 g (0.1 mol) of 4-nitrophenol, 20.6 g (0.12 mol) of propyl iodide, 16.56 g (0.12 mol) of calcined potash in 150 ml of dimethylformamide was kept at 70 -80 ° C 2.5 hours. The reaction mixture was poured into 250 ml of water. The oil layer was extracted with sulfuric ether. The ether layer was washed with water, dried with sodium sulfate. The solvent residue was distilled off under reduced pressure. Received 4-propyloxynitrobenzene. Yield 15.75 g (87%).

Stage 2. A mixture consisting of 15 g (0.08 mol) of 4-propyloxy nitrobenzene, 3 g of a Raney nickel catalyst obtained from a standard alloy, and 100 ml of ethanol was placed in a reactor and hydrogen was passed under vigorous stirring until the reaction was completely removed. a mixture. It was believed that the reaction mixture had finished absorbing hydrogen when the liquid level in the gas burettes did not change for 20 minutes. The amount of hydrogen absorbed in the reaction was fixed using gas burettes. Recovery was carried out at a temperature of 60 ° C and a hydrogen pressure of 0.1013 MPa. The hot reaction mixture was filtered from the catalyst on a Buchner funnel, after pouring 80 ml of 40% hydrochloric acid into a Bunsen flask. The resulting yellow solution was evaporated in a water bath. Received 4-propyloxyaminophenol hydrochloric acid. Yield 14.4 g (96%).

Stage 3. A suspension of 2 g (0.011 mol) of hydrochloric acid 4-propyloxyaminophenol in 10 ml of water at a temperature of 0-2 ° C and vigorous stirring was simultaneously added a solution of 1.7 g (0.024 mol) of sodium nitrite in 6.8 ml of water and 6.8 ml of a 25% hydrochloric acid solution. The end of the diazotization reaction was monitored by a stable blue spot on iodine starch paper. After that, a solution of 2.05 g (0.022 mol) of phenol in 6.8 ml of a 6% sodium hydroxide solution was added to the reaction mass. The precipitate was filtered off. Received 4-propyloxy-4'-hydroxyazobenzene. Yield 2.16 g (80%). T _pl = 90 ° C.

Step 4. To a mixture of 2.56 g (0.01 mol) of 4-propyloxy-4'-hydroxyazobenzene and 18.5 g (0.2 mol) of epichlorohydrin, 0.8 g (0.02 mol) was added. sodium hydroxide in the form of a 40% aqueous solution. The reaction mixture was kept at a temperature of 80-85 ° C for 5 hours, cooled, the precipitate formed was filtered off, washed with a 40% aqueous sodium hydroxide solution, then with distilled water until neutral, and recrystallized from ethanol. The desired product 4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene was obtained. Yield 2 g (65%). _Mp = 153 ° C. Found (%): C 68.57; H 5.83; N, 8.18. Calculated (%): C 69.23; H, 6.41; N, 8.97.

Example. The use of the claimed compounds as a photothermal stabilizer of PVC.

PVC was mixed with a plasticizer dioctyl phthalate (DOP) and the claimed compound as a stabilizer, placed in a container and the mixture was left to swell in an oven at 120 ° C for 30 minutes. Then the mixture was loaded onto laboratory rollers and rolled at 150 ° C. Plates were cut out of the flared mixture and pressed at 160 ° C and a pressure of 5 MPa for 4 min, followed by cooling in the press. The resulting sample was placed under a DRT-375 lamp with a power of 375 W at a distance of 20 cm. Heat and light aging was carried out at 70 ° C for 72 hours.

100 × 10 mm samples were cut from the initial (before aging) and aged polymer films. Standard samples were clamped in the clamps of a tensile testing machine РМ-30-1 and the load was determined at which the sample F _i breaks and the length of the working section of the sample, measured at the time of its break Δl _i , is increased according to GOST 14236-86.

Tensile strength (tensile stress) was calculated by the formula:

где F_i - разрывная нагрузка. А_i - сечение образца.

where F _i is the breaking load. And _i is the cross section of the sample.

The average of 30 results was determined.

The elongation (ε _p ,%) at break was determined by the formula:

где l_i - начальный размер i-го образца.

where l _i is the initial size of the i-th sample.

The average of 30 results was determined.

Resistance to light and heat aging was determined as the percentage of preservation of the property (σ and ε _p ) after light and heat aging.

Comparative samples using calcium stearate and ED-20 epoxy as stabilizers were prepared and tested according to the same GOST 8979-85 as for the claimed compound.

Table 1 shows examples of PVC-based compositions.

Table 2 shows the test results of the samples for light and heat resistance.

The data of table 2 clearly confirm that the claimed compound exhibits at the same time high light-stabilizing and heat-stabilizing abilities, without requiring the presence of salts of organic acids.

Table 1.
Compositions of compositions based on polyvinyl chloride. Name of ingredients The content of the ingredients, parts by weight 1 (prototype) 2 (prototype) 3 (prototype) four 5 1.PVC one hundred one hundred one hundred one hundred one hundred 2.DOF 40 40 40 40 40 3. Calcium stearate 2 2 2 - - 4. ED-20 0.2 0.4 2 - - 5.4- (2,3-epoxypropoxy) -4'-propyloxyazobenzene - - - 0.1 0.4

Table 2.
The test results of the samples for light and heat resistance. Indicator one 2 3 four 5 Tensile stress, MPa - under normal conditions 21.6 21.0 20,0 24.3 25,2 - after light thermal aging 19.9 20.7 19,2 24.2 25.0 Resistance to aging,% 92.00 98.60 96.00 99.38 99.21 Elongation at break,% - under normal conditions 232 224 200 195 213 - after light thermal aging 212 170 126 216 221 Resistance to aging,% 91.4 75.9 63.0 110.7 103.9

Claims (1)

4- (2,3-Epoxypropoxy) -4'-propyloxyazobenzene, exhibiting the properties of a light thermal stabilizer of polyvinyl chloride.