RU2621335C1 - Polyolefin composite based on elastomer, modified by carbon nanotubes to increase electrical conductivity of polymer matrix composites - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: polyolefin composite based on an elastomer modified with carbon nanotubes, contains polysiloxanes of the following structure (-R₁R₂Si-O-R₃R₄Si-)_m, where R_i - H, -C_nH_2n+1 at n = 1-20, with the following component ratio, wt %: multi-walled carbon nanotubes 10-25; polysiloxanes 2-5; polyolefin elastomer - the rest.

EFFECT: increasing the electrical conductivity of polymer matrix materials.

1 tbl, 1 ex

Description

The invention relates to the field of structural materials and polymer nanocomposites, in particular to polymer compositions containing nanodispersed additives in order to increase their electrophysical properties.

The present invention provides a material that is a polymer composite filler modified with carbon nanotubes, designed to significantly increase the electrical conductivity of polymer matrix composites.

The interest in the chosen research subject is due to the fact that structural materials used in aerospace engineering, automotive and other high-tech industries should have a set of high operational and technological characteristics, including strength indicators, heat and electrical conductivity, and the ability to be processed into products using simple high-performance methods . In most cases, metals with the required set of characteristics are used for these purposes, however, studies of recent years show that they can be successfully replaced with polymer composites with the corresponding set of properties.

Methods for preparing compositions based on carbon nanotubes and polyolefins are known in the art.

Known patent RU 2490204 a method for producing nanocomposites based on polyolefins used in the manufacture of various products, such as films, sheets, pipes, threads and fibers having high bulk and surface conductivity. The technology uses carbon nanotubes previously mechanically ground in water with the addition of a water-soluble polymer with a concentration of 0.01-0.1 wt.%. The resulting suspension is dispersed by ultrasound at a maximum medium temperature of not higher than 70 ° C. Then, the resulting suspension is applied to the surface of the polyolefin granules and dried. The obtained granules of the nanocomposite contain up to 0.5 wt.% Carbon nanotubes.

The disadvantage of this technology is the use of non-standard equipment, as well as the addition of an additional stage of preparation of a polymer nanocomposite.

The technical problem to which the present invention is directed is to increase the functional properties of polymer composites, in particular electrical conductivity.

The required technical result is achieved in that the polyolefin composite based on an elastomer modified with carbon nanotubes contains polysiloxanes in the following ratio of components,% wt.%: Carbon nanotubes 10-25; polysiloxanes 2-5; polyolefin elastomer - the rest. The presence of polysiloxanes in the polymer composite promotes a homogeneous distribution of carbon nanotubes in the polymer matrix.

A new technical result achieved by adding this composite filler to polymer matrix composites is a significant increase in their electrical conductivity due to the homogeneous distribution of carbon nanotubes in the bulk of the composite. The homogeneous distribution of carbon nanotubes in the volume of the polymer matrix is facilitated by the use of polysiloxanes in the polymer nanocomposite of the following structure: (-R ₁ R ₂ Si-O-R ₃ R ₄ Si-) _m , where R _i -H, -C _n H _{2n + 1} at n = 1-20).

Distinctive features of the proposed technical solution increased the conductivity of polymer matrix composites by an order of magnitude.

The achievement of improved indicators of appointment is illustrated by the following research and experiment data.

An experimental test revealed an increase in electrical conductivity by two orders of magnitude compared to a polymer matrix composite without the addition of a polyolefin composite modified with carbon nanotubes.

Example.

As starting materials are used:

- multilayer carbon nanotubes with a diameter of 20-30 nm, a length of 5-7 microns;

- polyolefin elastomer (LC 370);

- polysiloxane (-R ₁ R ₂ Si-O-R ₃ R ₄ Si-) _m , where R _i -H, -C _n H _{2n + 1} at n = 1-20.

The components were mixed in a two-roll mill (BL-6175-A) at a temperature of 120 ° C for 20 minutes. The ratio of components in the manufactured experimental samples is presented in table. one

Further, using the obtained experimental samples, polymer-matrix composites were manufactured by injection molding on a Haitan SA 900 injection molding machine with the following ratio of components:

Polypropylene PPG 1120-16 - 90 wt. %, sample 1 -10 wt.%;

Polypropylene PPG 1120-16 - 90 wt. %, sample 2 -10 wt.%;

Polypropylene PPG 1120-16 - 90 wt. %, sample 3 -10 wt.%.

According to the results of volume electrical resistance, the following results were obtained:

sample 1 -10 ^-3 S / m;

sample 2 -10 ^-3 S / m;

sample 3-10 ^-1 S / m.

Claims (1)

A polyolefin composite based on an elastomer modified with carbon nanotubes to increase the conductivity of polymer matrix composites, characterized in that the composite further comprises polysiloxanes of the following structure (-R ₁ R ₂ Si-O-R ₃ R ₄ Si-) _m , where R _i -H, -C _n H _{2n + 1} at n = 1-20, with the following ratio of components, wt.%: Multi-walled carbon nanotubes 10-25; polysiloxanes 2-5; polyolefin elastomer - the rest.