RU2536141C2 - Epoxy composition for highly strong alkali-resistant constructions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: epoxy composition of hot hardening for manufacturing fibreglass plastic armouring for the reinforcement of concrete constructions includes an epoxy diane oligomer of brand ED-20 (100 wt.p.), a hardening agent - iso-methyltetrahydrophthalic anhydride (80 wt.p.) and a catalyst of the polymerisation reaction - 2,4,6,-tris(dimethylaminomethyl)phenol (1.5 wt.p.). It additionally contains carbon type nanomaterials (0.05-1.5 wt.p.), representing carbon nanotubes (CNT), or carbon nanofibres (CNF), or a mixture of carbon nanomaterials: fullerene, nanotubes, nanofibres (MCNM), or soot carbon (soot) as a modifying additive.

EFFECT: invention makes it possible to increase mechanical strength, elasticity modulus, alkali-resistance and temperature of vitrification of the obtained products.

2 tbl, 21 ex

Description

The invention relates to an epoxy composition as a binder for producing high-strength, heat-, alkali-resistant fiberglass materials that can be used in the manufacture of reinforcement for hardening concrete structures.

Describes a polymer composition containing an epoxy diane oligomer ED-20, isomethyltetrahydrophthalic anhydride (iso-MTHFA), a polymerisation reaction catalyst - 2,4,6, -tris (dimethylaminomethyl) phenol, as well as carbon-type nanomaterials.

Carbon-type nanomaterials are carbon nanotubes (CNTs), or carbon nanofibres (CNFs), or a mixture of carbon nanomaterials: fullerene, nanotubes, nanofibres (CFSM), or carbon black (soot).

The proposed epoxy-polymer nanocomposite and fiberglass based on it have high alkali resistance, increased mechanical strength and elastic modulus, and a high glass transition temperature.

The invention relates to an epoxy anhydride curing composition, widely used to obtain high-strength, heat-, alkali-resistant fiberglass composite materials. The resulting polymer composite materials can be used for the manufacture of structural reinforcement operating in a wide temperature range.

The development of a polymer matrix of a composite material is an important technological task, since many properties of polymer composite materials are determined by the matrix. By selecting the composition and properties of the filler and binder, their ratio, the orientation of the filler, you can get materials with the desired combination of operational and technological properties.

Recently, polymer nanocomposites have become especially distinguished among polymer composites, which have a number of unique characteristics due to a strong increase in the interface surface area, which allows, with minimal degrees of filling, to significantly improve physicomechanical properties, heat and heat resistance, electrical conductivity, antifriction properties, etc. .d. Today, the following nanofillers can be distinguished: carbon nanotubes and nanofibres, fullerenes, inorganic nanotubes, layered aluminosilicates, metal nanoparticles, magnetic nanoparticles. [Polymer nanocomposites. / Ed. Yu-Wing Mai, Zhong-Zhen Yu. -M. : Technosphere. 2011]

Known epoxy binder for fiberglass containing epoxy oligomer ED-20, hardener iso-MTHFA, catalyst 2,4,6, -tris (dimethylaminomethyl) phenol and modifier - plasticizer EDOS. [RU 2145617 C1 02.20.2000] Fiberglass based on the specified binder have good adhesion to fiberglass, but lack of physical and mechanical strength.

An epoxy composition based on the reaction product of ED-20 with a mixture of isomeric products of diphenylmethanediisocyanate, hardener i-MTHFA and a catalyst 2,4,6, -tris (dimethylaminomethyl) phenol is also known. [RU 2355722 C2 05/20/2009] The obtained polymer material has increased values of bending strength and heat resistance.

The disadvantage of this composition is that the process of obtaining the product of the interaction of the resin ED-20 with a mixture of isomeric products based on diphenylmethanediisocyanate will complicate the process of obtaining products from fiberglass.

Known core for reinforcing concrete, consisting of an epoxy oligomer ED-20, iso-MTHFA, an accelerator of triethanolamine and fiberglass. [RU 2220049 C2 12/27/2003]

The disadvantage of this invention is the relatively low bending strength of the obtained composite material.

Known containers made of fiberglass for ammunition [RU 100221 U1 12/10/2010], containing nano-additives (nanoclay, nanotubes, carbon black). The product has enhanced impact and fire resistance characteristics. The disadvantage of this fiberglass product is the low glass transition temperature.

Known composite reinforcing product for building structures based on epoxy resin ED-20, iso-MTHFA, triethanolamine accelerator and modifying additive - hydroxyl-containing aromatically conjugated hydroxyphenylene. [RU 2461588 C1 09/20/2012] The obtained composite material has an insufficient modulus of elasticity and low alkali resistance.

The closest in technical essence to the claimed invention is an epoxy composition for the manufacture of products with high resistance to cracking [RU 2405795 C1 10.12.2010]. The composite material contains carbon nanotubes and wollastonite, and has high tensile and bending strength. The disadvantage of this invention is the too laborious process of dispersing carbon nanotubes, the modification of wollastonite, followed by removal of the solvent, and the insufficiently high heat resistance of the material.

The objective of the present invention is to increase the physico-mechanical characteristics, heat resistance and alkali resistance of materials obtained on the basis of an epoxy composition of the composition: ED-20, isomethyltetrahydrophthalic anhydride and 2,4,6-tris (dimethylaminomethyl) phenol, which due to its high technology is widely used in the manufacture of fiberglass composite materials, in particular fiberglass reinforcement for concrete structures.

The technical result consists in increasing the mechanical strength, elastic modulus, alkali resistance and glass transition temperature of products based on the proposed composition.

The technical result is achieved by the fact that the hot curing epoxy composition as a binder for the manufacture of fiberglass materials includes an ED-20 epoxy Dianne oligomer, hardener is isomethyltetrahydrophthalic anhydride (iso-MTHFA) and a polymerization reaction catalyst according to the invention as a modifying additive it additionally contains carbon-type nanomaterials, which are carbon nanotubes (CNTs), or carbon nanofibres (CNFs), or a mixture of carbon nanotubes aterialov: fullerene, nanotubes, nanofibers (SUNM), or particulate carbon (soot), with the following component ratio, wt. hours

Epoxy Oligomer - 100

iso-MTHFA - 80

The above catalyst is 1.5

Carbon nanomaterials - 0.05-1.5

The implementation of the composition according to the invention has improved the physical and mechanical characteristics, glass transition temperature and alkali resistance of the composites based on it.

The method was carried out as follows.

To improve the quality of the mixture, ultrasonic treatment of the filled composition was used. The carbon nanomaterial was mixed with the components of the polymer matrix using an IL - 10-0.1 ultrasonic generator with a frequency of 22 kHz, which made it possible to process the mixture with a power of 750 W (intensity 9 W / cm ² ). The duration of the RCD was determined experimentally on the basis of the highest operational characteristics of the obtained polymer [Sitnikov P.A., Belykh A.G., Vaseneva I.N., Ryabkov Yu.I., Kuchin A.V. Modification of the epoxy anhydride matrix with carbon black. // Journal of Applied Chemistry. 2012, T. 85., Issue 4. S.676-678].

Examples of implementation

Example 1

In 80 mass. including isomethyltetrahydrophthalic anhydride add 0.05 mass. including carbon nanotubes and this mixture is dispersed by ultrasound using an ultrasonic generator IL at a frequency of 22 kHz for 15 minutes

Then add a dispersed ultrasound mixture of nanomaterials in anhydride in 100 mass. including epoxy oligomer brand ED-20, 1.5 mass. including 2,4,6, -tris (dimethylaminomethyl) phenol, stirred with a mechanical stirrer for 30 minutes, after which this mixture was poured into metal molds and solidified in a stepwise mode: 100 ° C - 1 h, 160 ° C - 3 h , 100 ° C - 1 h.

Examples 2-20 are carried out analogously to example 1, the type of carbon nanomaterial, its amount and properties of the obtained compositions are shown in table 1.

Example 21. Carry out according to the method described in the inventions [RU 2339773 C2 11/27/2008; RU 2324797 C1 05/20/2008]. A binder for glass roasting impregnation was prepared according to examples 1-20.

The properties of the obtained composite materials were characterized using standard techniques. The ultimate tensile and bending stresses were determined according to GOST 11262-80 and 4648-71, respectively, using a test machine IR 5057-50.

The alkali resistance of the materials obtained was determined according to GOST 12020-72 "Plastics. Methods for determining the resistance to the action of chemical media."

The glass transition temperature was determined by differential scanning calorimetry (DSC). The properties of the cured binder with additives of carbon materials are shown in table 1.

Studies have shown that the modification of a standard binder based on ED-20 and iso-MTHFA with small amounts of nanostructured carbon materials can significantly increase the elastic modulus (2 times) and alkali resistance (10 times) of the obtained material compared to the analogue [RU 2461588]. The glass transition temperature increased by 20-30 ° C compared with the prototype. The optimal additive content for carbon nanotubes (CNTs) is 0.05 mass%, for carbon nanofibers (CNF) 0.1 mass%, for a mixture of carbon nanomaterials 0.1 mass%, for soot 1 mass% .

The claimed composition as a binder can be used for the manufacture of products from composite materials, in particular fiberglass reinforcement for hardening concrete structures. The properties of such fiberglass are shown in table 2.

The destructive load during bending of samples of fiberglass based on the proposed composition is higher than that of the prototype 2.5-3 times. After boiling in alkali, the strength of fiberglass samples with nanocarbon deteriorates by 5-12%, and for samples based on a pure matrix, by 30%.

Thus, the use of the claimed invention will improve the quality of products by improving the physico-mechanical, thermophysical properties and alkali resistance of the binder.

Claims (1)

Hot curing epoxy composition as a binder for the manufacture of fiberglass reinforcement for hardening concrete structures includes an ED-20 epoxy diane oligomer, hardener is isomethyltetrahydrophthalic anhydride (iso-MTHFA) and a polymerization reaction catalyst, characterized in that as a modifying additive it additionally contains carbon-type nanomaterials, which are carbon nanotubes (CNTs), or carbon nanofibres (CNFs), or a mixture of carbon nanomaterials in: fullerene, nanotubes, nanofibers (SUNM), or particulate carbon (soot), with the following component, pbw
Epoxy Oligomer - 100
iso-MTHFA - 80
The above catalyst is 1.5
Carbon nanomaterials - 0.05-1.5