SU535329A1 - Composition for the manufacture of plastics - Google Patents

Description

one

The invention relates to the field of stabilizing polymers during thermal and thermal-oxidative degradation, and to stabilizing aromatic polyamides, and can be used to increase the temperature limit of their performance and improve the mechanical properties of products made from them.

There are known methods for stabilizing polyamides by introducing low molecular weight compounds, for example, metals, amines, organosilicon compounds into them by various methods.

However, these compounds are not effective for stabilizing aromatic polyamides due to their relatively low heat resistance. In addition, the possibility of a notary stabilizer due to its volatility is not excluded.

Closest to the proposed comnose for stabilizing aromatic polyamides, comprising as a stabilizer high-molecular compounds, for example, brominated polyphenylethyl. However, the stabilizing effect of these nro compounds is only for 30 minutes of heating in air at temperatures not exceeding 350 ° C.

The aim of the invention is to increase the temperature of the boundary of the working ability of aromatic polyamides during thermal and thermal-oxidative degradation. Aromatic polyamides, despite their very valuable properties, are used on a much smaller scale than aliphatic ones, since they can not be processed from a melt into monolithic products only at temperatures close to their thermal decomposition. Therefore, an increase in the stability of aromatic nolyamides at temperatures of their processing into products is relevant.

This goal is achieved by introducing a high molecular weight stabilizer, an lg-carborane-containing aromatic polyamide, into the aromatic polyamides.

Suitable in aromatic nolyamida Tina

-P C-Cg C-N - Er -1 U 11 1 1 it H j rt where in the acid component

.f, P1, TOG (and, 17),

in the amine component

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enter 0.5-2.0 weight. % L1-carborane-containing polyamide (obtained according to the author. St. USSR 254074)

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Example 3. To a 5% solution of polyamide IV in dimethylformamide was added 1.0 wt. % polyamidocarboraia V. Further operations are similar to those indicated in example 1.

The test results are presented in Table. 1 and 2.

table 2

The number of carbon oxides (mol / mol

structural units) formed during

thermal and thermal oxidative degradation

stabilized and unstabilized

polyamide samples (duration

heating -1 hour).

The amount of aromatic polyamide is 99.5-98 wt. %

Example 1. To a 5% solution of polyamide I in dimethylformamide was added 0.5 weight. After complete dissolution, the polymer mixture is precipitated in water, filtered and washed on the filter with water and methanol. Then extracted in the apparatus of Soxhlet with methanol for 8 hours and dried in vacuum mm RT. Art. at 60-70 ° C until constant weight.

The thermal stability of polymers was studied under isothermal heating conditions for 60 minutes in vacuum and in the presence of oxygen in the temperature range of 300-450 ° C, followed by quantitative determination of decomposition products and weight loss.

Example 2. To a 5% solution of polyamide I, 2.0 weight by weight of dimethylformamide was added. % polyamidocarborane VI. Further operations are similar to the operations indicated in irimer 1.

Table I

Depth of decomposition of stabilized

and unstabilized control samples

polyamides I, II, IV in thermal

and thermo-oxidative degradation (heating time 1 hour)

Example 4. 0.5 g of a mixture of polyamides obtained by the method indicated in Example 1 is loaded into an iress mold, heated to 370 ° C, the polymer is pressed, at this temperature for 2 minutes, a pressure of 50 kg / cm is applied The iress form is cooled to a comed temperature and depressed.

A test is then carried out to test the specific toughness of the i-beam and the polymer.

The test results are presented in Table. 3

Table 3

Impact resistance of stabilized and non-stabilized polyamide bars

As can be seen from the data table. 1-3, the introduction of a small amount (0.5-2 wt.%) And “-carborane-containing polyamides into aromatic polyamides significantly increases the resistance of these polymers to heat and oxygen in the temperature range 300-450 C. 56

Claims (1)

The invention claims the performance and improvement of the mechanical composition for the manufacture of plastics, contains l-carborane-containing polyamide comprising an aromatic polyamide and in the following ratio of components, a biliser, characterized in that 5 wt. %: aromatic polyamide 99.5-98, in order to increase the temperature limit of its g-carborane-containing polyamide 0.5-2. 535329 properties as a stabilizer