The word "epoxy" is known to almost every person. But epoxy resin, the use of which is quite common today, is a type of synthetic resin. She appeared in the 50s. of the last century and immediately gained popularity due to its universal properties.
Today, epoxy resins are used in industrial production and households. The possibilities of application are constantly expanding due to the development of formulations with improved characteristics.
Epoxy resin description
In terms of chemical composition, epoxy resin is an oligomeric synthetic compound. These materials are in demand today in almost all industries. In free form, epoxy is not used, but in combination with a hardener, it is able to exhibit unique properties after the polymerization reaction. When epoxy resin is combined with curing agents, you can get:
- hard hard materials;
- softer and stronger products;
- rubber-like materials.
Epoxy resins are resistant to the following substances:
- halogens;
- acids;
- alkali.
However, dissolution occurs in esters and acetone without film formation. After curing, the epoxy resin composition does not emit volatile substances, and shrinkage is negligible.
Features of dilution of epoxy resin
If you are wondering how to dilute epoxy, you should know that the lack or excess of hardener in the composition can adversely affect the quality of the polymer, while it remains resistant to heat, but its strength decreases, the ability to resist chemicals and water are saved. If not enough hardener is added, the product may be sticky due to unbound resin.
Before you dilute the epoxy, you need to understand that excess free hardener is released on the surface of the polymer during operation. To obtain different compounds, curing components and resin are used in different proportions, this can be found in the instructions. If we are talking about a modern compound, then the ratio most often looks like this: 1 to 2 or 1 to 1.
Epoxy dilution recommendations
Today, there is an opinion that when using a hardener inmore than normal volume, the polymerization reaction will occur faster. This thought can be considered delusional. The easiest way to speed up the process is to raise the temperature of the reacting mixture.
If you want to speed up the process three times, then the temperature should be increased by 10 °C. If you are thinking about the question of how to dilute epoxy resin, then you should know that today special compounds are known that contain curing accelerators in their composition. Epoxy compounds can also be found on sale, which harden at a low temperature. The type of hardener and the temperature of the mixture act as the main factors that affect the cure rate.
Dilution of epoxy resin: compositions with different polymerization temperatures
Epoxy resin can be cured at temperatures ranging from -10 to +200 °C, everything will depend on the type of composition used. To date, resins of hot and cold curing are known. Cold hardener and epoxy are the most commonly used in the home. You can meet such a composition in production conditions with low power, as well as where heat treatment is unacceptable.
To obtain high-strength products that will be able to withstand high loads and temperatures, as well as exposure to chemicals, hot-type curing components are used. During hot polymerization, a dense network of molecules is formed. There are also compounds and their oxides that are capable ofpolymerize in sea water and in humid environments.
Scope of application
Epoxy materials are now widespread throughout the world, they have been known since the middle of the last century. The nature of the application of these materials has undergone significant changes in recent years, but the use remains traditional in several areas, among them:
- impregnation of fiberglass and fiberglass;
- waterproofing coating;
- creation of chemical-resistant coatings;
- manufacture of transparent solid material for fiberglass products.
Epoxy resin, the use of which is quite common today, can act as an impregnating agent for bonding parts in electrical engineering, automotive, aviation, radio electronics and industry. In this case, the composition is used in the production of fiberglass in mechanical engineering and shipbuilding, construction, in workshops for the repair of car body elements and boat hulls.
Work with epoxy resin is carried out where there is a need to waterproof the walls, as well as the floors of basements and pools. With the help of epoxy resin, it is possible to produce materials and paints for exterior and interior decoration of buildings, as well as impregnation, which will provide waterproofing of porous materials and their increased strength, among them wood and concrete should be distinguished.
For reference
Epoxy can lie downinto the basis of a transparent solid material, which is made by pouring into a mold. At the next stage, the products are processed mechanically, such as: grinding and cutting. Used for fiberglass products in design work, electronic industry, construction and household.
Epoxy work: surface preparation
Working with epoxy involves the need to prepare the surface before applying the composition. Only then will it be possible to achieve high-quality adhesion. Therefore, before diluting the epoxy, first prepare the surface. To begin with, the base degreases. The surface must be free of traces of oil and grease. The surface is cleaned using solvents or effective detergents. It is important to make sure that there is no gloss.
The top layer is removed by grinding. Small surfaces should be prepared by hand using sandpaper. The bases, impressive in area, are processed with grinders, and the resulting dust should be removed with a vacuum cleaner. In the manufacture of fiberglass or the layering of epoxy self-leveling floors, varnishes and paints, each subsequent coating should be applied on a not completely cured, still sticky previous layer.
If the technology and the requirements for the finished product allow, then the bottom layer, which is the substrate, should be sprinkled with fine sand. After curing, excess sand should bewill remove and apply a new layer of epoxy.
Preparing a large volume of epoxy
If you don't know the specific properties of epoxy resin, you may run into problems making the material in bulk. As the volume of epoxy increases, more heat is released. When boiling, the resin will foam, become cloudy white. This composition cannot be considered suitable for use. Thinners and solvents may be added to the resin to reduce viscosity. Even a small concentration of them can cause a decrease in the strength and heat resistance of the product. The result is thinner exudation from the polymer, which leads to a deterioration in the quality of the material.
Epoxies and hardeners must not contain water. If this happens, the composition will become cloudy and lose its properties. Today, a water-borne epoxy is produced. Similar compositions are diluted to achieve dispersion with distilled water. The two part epoxy must be mixed with a plasticizer. The resulting mixture is slowly heated, which is true if DBP is used. When using DEG-1, the composition must be mixed.
For thorough mixing, use a special nozzle on a drill or construction mixer. The proportions of resin and plasticizer are selected depending on the required plasticity, but most often the proportion of plasticizer varies from 5 to 10%. A hardener is added to the mixture. The resin is cooled to +30 °C to prevent boiling. The standard proportion of resin with hardener is 1 to10. To achieve uniform dissolution of the hardener, mixing should be ensured. Otherwise, the composition will turn out to be heterogeneous, and subsequently it will sweat.
Resin Crafts
Quite often, craftsmen make crafts from epoxy resin. These works may be accompanied by certain difficulties. The product should be transparent, there should be no air bubbles inside it. In the thickness and on the surface, the curing must be uniform. If the thickness is more than 2 mm, then the material is applied in layers after primary polymerization. Resin can be poured into molds. In order for the product to separate, the mold is lubricated with technical petroleum jelly or grease.
Epoxy resin dye will allow you to give the product any color. After completion of work, the product is kept at a temperature slightly above room temperature. After 3 hours, primary polymerization will occur, curing until peeling off, after which the product must be heated to accelerate the curing process for 6 hours. If you decide to make crafts from epoxy, then it is quite possible that you will not be able to use a special oven.
At room temperature, polymerization will take 2 weeks. If triethylenetetramine is added to the ingredients, the surface may remain sticky. The cast product must be processed mechanically in the future. Epoxy resin of domestic production is not so suitable for casting massive products, because it is characterized by uneven curing of the thickness.
Giving color to epoxy resin
Epoxy resin dyewill allow you to get a composition painted in a certain color at home. Manufacturers use dozens of surfactants to ensure that the pigment is evenly distributed. Pigmentation can reduce the transparency of the resin, sometimes it changes color, the resin darkens. Adding pigment should be done before the catalyst, but after adding the wax.
Technical characteristics of epoxy resin on the example of the composition of the brand ED-20
Epoxy resin, the characteristics of which will be listed below, is a honey-like yellowish liquid that is easily colored. The density at 20 °C of the environment is the limit of 1.16-1.25 kg/m3. Tensile strength is 40-90 MPa. Bending strength is equivalent to 80-140 MPa. The compressive strength is 100-200 MPa.
Polymerization temperature is 20°C or more. If you are interested in epoxy resin, the proportions of the mixture when combined with the hardener should be of interest to you. The latter should be used in the amount of 7 parts, while the resin is added in the amount of 1 part. The polymerization time of the composition is 1.5 hours. Water absorption in 24 hours is equal to the limit of 0.01-0.1%. Heat resistance varies from 55 to 170 °C. The impact strength is 5-25 kJ/m2.
Basic properties of epoxy resin
Before you decide where to buy epoxy resin, you should know its basic properties. Among others, one should highlight the low resistance to cracking, as well as more impressive toxicity compared to acrylicresins. The properties of the epoxy resin indicate that the composition is highly viscous and should be used in conjunction with solvents. To reduce the viscosity of the resin, you can heat the mixture or add a solvent to it. In both cases, the resin will become more fluid. It can be applied with a roller or brush and will quickly soak through fiberglass and penetrate porous surfaces such as wood.
Conclusion
Quite often, consumers wonder where to buy epoxy. Today, this material is offered by many companies, among others, the Karbo composite supermarket, which is located in Moscow at the address: Volgogradsky Prospekt, 42.
