PU Sealant, Hybrid Sealant, Silicone Sealant and Acrylic Sealant: The Complete Guide to Sealants in Construction
You may have already bought a tube of silicone sealant, pu sealant, hybrid sealant or acrylic sealant to make a repair or for some stage of your job site, right?
But when you bought it, did you know why you were choosing specifically that type of sealant?
Ever been in doubt like, what is the difference between a pu sealant, acetic silicone sealant, neutral silicone sealant, acrylic sealant or hybrid sealant?
There are several factors that can influence the purchase of a sealant and more importantly, the specification of the correct product for each stage of the job.
Not all sealants are the same! Didn't you know?!
So come along with us in this Complete Guide to Sealants where you'll learn all about it and choose the right sealants for your job site!
What is Sealant?
You may have heard about sealants, but you may be wondering what's so special about knowing what a sealant is.
Precisely this definition will guide this article to talk about products that seal structures and not to get into another subject very close, which are the adhesives.
So let's understand about sealants?
As I said, the definition of sealing in construction can be said as, leak prevention work, in this way, sealants are used to seal joints or openings between two or more substrates.
The main role of a sealant is to prevent water, air or other substances from entering or leaving the structure, even with some movement of the substrates where it has been applied.
The distinction between adhesives and sealants is not always very clear, but it is worth defining that line. Sealant is intended to seal a joint, and the material chosen for the sealant has the ability to move and adhere to the substrate. Adhesives, on the other hand, are materials that are designed to hold substrates together by bonding surfaces and are often used as an alternative to mechanical fasteners such as screws and nails.
Some materials can be considered both sealants and adhesives and fulfill the roles of sealing and bonding between surfaces. These types of materials are known as structural sealants.
All sealants must fulfil at least three main functions:
- Sufficiently fill an expansion or movement joint to create a seal between substrates;
- Form a barrier against gases and liquids;
- Maintain sealing between the structures, allowing a certain amount of movement between the parts.
History of Sealants (Brief History)
I do not want to prolong the subject too much, but I believe it is interesting to present, at least, a historical line of the sealants developments. From the first technologies that were adopted in construction, until the most recent ones.
The first sealant technology, marketed on an industrial scale, was introduced in the early 1940s with polyisobutylene. The main applications were in construction, automotive and electrical.
In the late 1940s, the first polysulfide-based sealants were introduced to the construction and aerospace markets.
A decade later, in the late 1950s, solvent-based acrylic sealants entered the construction market. This type of sealant, had a thermoplastic characteristic, unlike newer acrylic technologies with elastomeric characteristics.
Silicone sealants entered the market in the early 1960s. This type of sealant, with its elastomeric characteristic, was and still is used in construction, aerospace, electrical, electronics and automotive applications.
As early as the 1960s, water-based acrylic sealants and the first polyurethane sealants began to be used in construction and polyurethane sealant gained ground primarily in the automotive industry.
In the mid-1980s, silicon acrylic sealants emerged, which here in Brazil is popularly known as water-based silicone sealant. At the end of the 80s, the technology of polyether-based sealants began, known in our market as modified silicone sealant, or MS sealants.
The polyurethane sealants most used in Brazil today is the polyurethane technology known as hybrid, because it closes the chain through a tip with silicone. This sealant technology emerged in the early 1990s. At the end of that decade, polyisobutylene, also hybrid, appeared on the market.
Here in Brazil, currently, the main chemical bases used to manufacture sealants for civil construction are polyurethane (PU), acrylic, hybrid polyurethane, polyether and silicones, both neutral cure and acetic cure.