RU2408552C1 - Nanostructuring binder for composite construction materials - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to composition of a nanostructuring binder for composite construction materials based on liquid glass and nanostructuring additives used for making acid-resistant concrete, putty and other compositions. The nanostructuring binder for composite construction materials contains liquid glass, tetrafurfuryl ester of orthosilicic acid and a hardener. A portion of the liquid glass is replace with organic alkaline liquid glass containing an organic cation 1,8-diazabicycloundecene-7 or 1,5-diazabicyclononene-5-2-4.

EFFECT: use of the nanostructuring binder enables to increase acid resistance, water resistance and strength of construction materials and widens their field of use.

2 cl, 4 tbl

Description

The invention relates to building materials used for the manufacture of acid-resistant concrete, putties, putties and others, namely, compositions based on water glass.

To increase the strength, thermal and fire resistance of building materials and structures made of them, tetrafurfuryl esters of orthosilicic acid (tetrafurfuryloxysilane - TFS) are introduced into the binder. Moreover, tetrafurfuriloxysilanes are synthesized by transesterification of tetraethoxysilane with furfuryl alcohol.

The composition of the binder contains, wt.%: Liquid glass - 80-95, tetrafurfuryloxysilane (TFS) - 2-7, hardener - sodium silicon fluoride 13. In this case, organic alkaline liquid glass is used as part of the liquid glass, where 8- diazabicycloundecene-7 or 1,5-diazabicyclononen-5 - 2-4.

The known composition of the binder composition for mixtures (A.S. No. 2008998, class B22C 1/22), containing the following components, wt.%:

acid curing epoxy resin - 23-72;

the product of the interaction of ethyl esters of orthosilicic acid with furfuryl alcohol (in terms of the main substance) - 8-52;

organic peroxide and / or hydroperoxide - the rest.

However, this composition is applicable only in foundry, namely, the compositions of mixtures cured by blowing with sulfur dioxide in the manufacture of cores and molds, requires special equipment to obtain the mixture.

The purpose of the invention is to increase the acid resistance, moisture resistance and strength of building materials and the expansion of their scope.

The use of soluble sodium silicates (liquid glasses) is explained by their wide use as binders for the manufacture of heat-resistant, chemically resistant materials. Liquid glasses exhibit high cohesive strength, are light and safe, have a low cost, do not corrode, do not evaporate flammable volatile components and do not worsen the environment during operation.

A water-soluble silicate containing an organic alkaline cation is prepared by reacting salts of the quaternary organic ammonium derivative with amorphous silica. Soluble organic alkaline silicates such as tetrabutylammonium silicate (TBAS) are used as a component for self-extinguishing of the binder.

The introduction of the orthosilicic acid tetrafurfuryl ester (TFS) into the binder of the nanostructuring component leads to the formation of SiO ₂ nanoparticles, which act as crystallization and nucleation centers, and furfuryl alcohol, which fills the silica matrix and forms a network polymer. The addition of TFS increases the mechanical and chemical resistance of the binder and is widely used for the preparation of acid-resistant concrete and putty (Anticorrosion Service of Enterprises: Ref. Ed. - Stepanov I.A., Savelyeva N.Ya., Figovsky OL.M .: Metallurgy, 1987 , p. 91-92).

Characteristics of the components used in the binder:

glass sodium liquid grade K with a mass ratio of SiO ₂ / Na ₂ O = 2.88 (GOST 13078-81);

hardener - sodium silicon fluoride Na ₂ SiF ₆ (GOST 6-09-1461-85);

nanostructural additive Si (O ₂ C ₅ H ₅ ) ₄ - products of the interaction of ethyl esters of orthosilicic acid with furfuryl alcohol (TU 59-020-04);

As ethyl esters of orthosilicic acid, tetraethoxysilane (C ₂ H ₅ O) ₄ Si (TU-6-02-708-76) with a SiO ₂ content in terms of silica of 60 wt.% was used.

By the interaction of tetraethoxysilane with the complete or partial replacement of its ethoxy groups with the furfuryloxy groups of furfuryl alcohol, tetrafurfuryloxysilanes (TFS) are obtained. Currently, tetrafurfuryloxysilanes are obtained in the form of experimental industrial samples.

Water-soluble silicate with organic cations of the type 1,8-diazabicycloundecene-7 and 1,5-diazabicyclononene-5 is manufactured by Polymate, Ltd (Israel) under the trade names DBUS and DBNS, respectively. The ratio of SiO ₂ / organic base for DBUS is 1.65: 1 and for DBNS 2.0: 1, respectively.

The content of silicates in liquid glasses is, wt.%: Liquid glass - sodium silicate grade K - 57.3; water-soluble silicate under the trade name DBUS - 63.8; water soluble silicate under the trade name DNNS - 62.3.

The proposed nanostructuring binder is obtained by laminar mixing of liquid glass containing alkali metal cations of the Na type; tetrafurfuryl ester of orthosilicic acid (TFS) and water-soluble silicate containing an organic alkaline cation of the type 1,8-diazabicycloundecene-7 or 1,5-diazabicyclononene-5 in the following ratio, wt.%:

liquid glass - 80-95;

tetrafurfuryl orthosilicic acid ester (TFS) - 2-7;

water-soluble silicate containing an organic alkaline cation - 2-4.

After mixing all the components of the binder, it must be used within 2-3 hours. Hardener is added together with a finely ground mineral filler.

The following binder compositions were prepared for the test, wt.%:

Composition 1:

liquid glass - 95;

tetrafurfuryloxysilane (TFS) - 3;

water soluble silicate under the trade name DBUS - 2.

Composition 2:

liquid glass - 88;

tetrafurfuryloxysilane (TFS) - 8;

water-soluble silicate under the trade name DBUS - 4.

Composition 3:

liquid glass - 92;

tetrafurfuryloxysilane (TFS) - 5;

water soluble silicate under the trade name DNNS - 3.

Composition 4:

liquid glass - 88;

tetrafurfuryloxysilane (TFS) - 8;

water-soluble silicate under the trade name DBUS - 4.

For experimental verification of the properties of the proposed binder, various construction materials were made: acid-resistant concrete, acid-resistant putties and putties.

Acid-resistant concrete was prepared by mixing the components in the following proportions (see table 1). Tests of silicate concrete, are shown in table 1, are presented in table 2.

The data in table 2 show that the compressive strength of concrete increases by 30%, and water permeability decreases by more than 15 times. Concrete on liquid glass without the addition of TFS had a compressive strength of less than 27.0 MPa.

Acid-resistant putties and putties were prepared by mixing the components (see table 3). The test results of putties and putties are presented in table 4. The test results show that the use of putty with a nanostructural binder increases the adhesive strength by 50%.

Table 1 Name of components of concrete mixtures Content, wt.% Concrete No. 1 Concrete No. 2 Concrete No. 3, without the addition of DNNS Concrete No. 4, without DBUS additive Binder, composition 3 13,4 - 13,4 - Binder composition 1 - 13,2 - 13,2 Silicate sodium (Ssp - 2700 cm ² / g) 1.8 1.7 1.8 1.7 Diabase powder (Ssp - 3000 cm ² / g) 18.0 18.0 18.0 18.0 Quartz sand (MKR - 2.4) 28.0 28.0 28.0 28.0 Granite crushed stone 38.8 39.1 38.8 39.1

table 2 Properties Concrete offered Concrete No. 1 Concrete No. 2 Concrete No. 3, without DNNS additive Concrete No. 4, without DBUS additive The limit of compressive strength, MPa 49.2 48.7 37.1 35,4 Water permeability, diffusion, 10 ^-7 cm ² / g After 7 days 0.42 0.48 8.77 8.96 After 30 days 0.14 0.16 6.31 6.44 Acidity coefficient after 360 days in 5% HCl 1,03 1,02 0.97 0.93 20% HCl 1.12 1,07 0.96 0.91 5% H ₂ SO ₄ 1.06 1.05 0.93 0.94 20% H ₂ SO ₄ 1.17 1.18 0.92 0.90

Table 3 Name of the components of the filler mixtures Content, wt.% Putty No. 1 Putty No. 2 Putty No. 3, without DBUS additive Filling No. 4, without DBUS additive Binder, composition 2 41.0 - 41.0 - Binder composition 4 - 34.0 - 34.0 Silicate sodium (Ssp - 2700 cm ² / g) 6.0 6.2 6.0 6.2 Diabase powder (Ssp - 3000 m ² / g) 53.0 - 53.0 - Andesite powder (Ssp - 2600 cm ² / g) - 59.8 - 59.8

Table 4 Properties Suggested putties Putty No. 1 Putty No. 2 Putty No. 3, without DBUS additive Filling No. 4, without DBUS additive Shear Force (ASTMD1002-05) Ceramics - steel, MPa 1,54 1.48 0.92 0.95 Ceramics - ceramics, MPa 1.90 1.94 1.18 1.22 Adhesive tensile strength, MPa Ceramics - Steel 0.98 1,04 0.47 0.51 Ceramics - Ceramics 1.27 1.30 0.55 0.54

Claims (2)

1. The composition of the nanostructural binder for acid-resistant concrete, containing water-soluble silicate and tetrafurfuryl ester of orthosilicic acid (TFS), in which part of the liquid glass is replaced by organic alkaline liquid glass containing the organic cation of 1,8-diazabicycloundecene-7 or 1.5 -diazabicyclononene-5, in the following ratio, wt.%:
liquid glass 92-95 tetrafurfuryloxysilane (TFS) 3-5 organic alkaline liquid glass 2-3 2. The composition of the nanostructuring binder for acid-resistant putties and putties has the following ratio of components, wt.%:
liquid glass 88 tetrafurfuryloxysilane (TFS) 8 organic alkaline liquid glass four