In construction and repair work, sealants are actively used today - pasty viscous materials with high adhesive and waterproofing properties. They are suitable for sealing joints, sealing joints and filling voids, gluing various materials. Sealants fill the gaps around the perimeter of the installed windows, seal the exit points of pipes and cables.
The main criteria for choosing a quality sealant are the following indicators:
- the degree of strength of the seam;
- resistance to various loads;
- good adhesion to various surfaces;
- minimum percentage of shrinkage;
- good elasticity;
- long service life;
- chemical resistance;
- environmental friendliness;
- no smell.
There is a fairly large range of sealing compounds on the market today, which can be classified according to several parameters. There are many factors to consider when choosing the right sealant. Even experts sometimes argue about which composition in a given situation will be the most optimal.
Sealants are classified according to composition. There are single-component, as well as two- and three-component. The first are good because they can be applied immediately, simply squeezing out of the can. The latter also have their advantages.
According to the chemical composition, we can classify these materials into acrylic, silicone, polyurethane. All of them have their own characteristics.
Advantages and application of silicone compounds
Silicone compounds are designed to create tight joints during the installation of window and door structures. They create reliable protection against moisture and blowing. They can be used for interior and exterior repairs. Silicone sealant contains rubber, which is famous for its ability to adhere to any materials - glass, wood, metal, ceramic. He is hardy to the influence of low and high temperatures, is not afraid of sudden changes in the weather. It is undesirable to paint silicone compositions, since the components contained in paint and varnish products reduce the elasticity of rubber. Such sealants are produced in various colors, so you can choose a specific composition in such a way that the seam obtained with it will not be noticeable against the background of the treated surfaces.
The advantages of silicone sealing compounds are environmental friendliness, no smell and no harmful fumes during application. To apply such sealants, you do not need to wear gloves and a mask.
Thiokol compositions - properties and scope
Over the past decades, sealing materials based on oligomers with terminal functional groups, primarily polysulfide ones - thiokol sealants and mastics, have found wide distribution in various sectors of the national economy.
Acrylic compositions - properties and scope
This type of sealant is intended for repairing cracks in concrete structures, sealing joints and seams. Acrylic compositions serve for many years, retaining their elastic structure. They can withstand vibrations and short-term loads without consequences. The sealed seam can be painted with any paint without fear of damaging it. These sealants adhere well to plastered, wooden, brick, concrete structures. After applying the acrylic composition, the surface can be plastered and painted. Since these sealants do not contain toxic components, they do not require special protective measures during application and can be used indoors in any quantity.
Polyurethane sealants
This type of sealants is a reliable material for gluing and sealing cracks, joints in a wide variety of structures made of wood, metal, brick, and iron. Polyurethane sealant can be bonded even over old sealant with the same composition. Seams have very high strength and retain their integrity under strong vibrations.
Polyurethane sealants must be applied with gloves and a respirator, as they contain components that are very hazardous to health. But these substances quickly disappear, therefore, in small quantities, polyurethane sealant can be used indoors.
Silicone sealants are considered the most popular, as they have excellent properties and are relatively inexpensive. They are resistant to sunlight, are not afraid of exposure to moisture and temperature fluctuations, and are resistant to chemical attack. They can be applied without pre-treatment of the surface with a primer. In addition, silicone sealants remain flexible in severe frosts, so they do not crack.
