Elastic bonds and seams with modified silane adhesives and sealants
First introduced in Japan at the end of the 80´s, modified silane adhesives and sealants are becoming more and more desired in industrial applications that require elastic bonding or sealing. Having reached the European and American markets, modified silane based systems are a good choice for elastic bonds and seams throughout industries, including automotive, transport, construction and many more.
Modified silane sealants and adhesives combine the advantages of polyurethanes and silicones, and cancel all their disadvantages. Modified silane polymers also very versatile, can be applied to almost any surface and allow for modification to make modified silane a perfect choice.
What is modified silane polymer?
Silane modified polymer (SMP), also known as silyl terminated polymer, consists of a polymer backbone which is terminated by silane groups. The silane groups can be independent or supported by urethane groups. This gives us two main types of SMP adhesives and sealants: silyl modified polyethers (MS polymers) and silyl modified polyurethanes (SPUR polymers). The former, MS polymer systems, are often preferred as sealants as they are more elastic and slightly less resistant than SPUR polymers. Both types of silane modified polymers are, however, also suitable for adhesive solutions.
Curing process of modified silane polymer adhesives and sealants
Modified silane polymer systems cure through polycondensation, also known as moisture curing, in room temperature. This means that the products use moisture in either the material or in the ambient to harden. With some products the curing starts from the outside and reaches the inside as last. Therefore, one must be careful not to apply too thick layers, as this may lead to poor curing and system failure.
Advantages of modified silane adhesives and sealants
Modified silane adhesives and sealants are the preferred option for many applications in a wide variety of industries. They are used for example for fixing solar panels, bonding side panels of trailers and vehicles such as trucks, assembly parts, container constructions and doors and windows (also in vehicles) as well as sealing joints wherever elasticity is needed. It is no wonder SMP systems are widely used, since they come with a great spectrum of advantages.
- Elastic bonds and seams: SMP systems remain flexible also after complete cure. The elasticity of the seams and bonds is not affected even by harsh environments.
- Easy to modify: silane modified adhesives and sealants can have different polymer backbones which partially define their set of properties. However, the properties can also be modified with help of additives and so-called boosters.
- Minimum surface preparation: in most cases through cleaning and degreasing of the surface is sufficient. Usually, these systems do not require a primer, thus the process is sped up. Note that some MS polymers do not cure in the presence of polyols: therefore, the cleaning substance should not contain these.
- Silicone and isocyanate free: most silane modified polymer solutions are environmentally friendly as they do not contain silicone or isocyanates. Some products may emit methanol during the hardening process, but also ethanol emitting, safer systems exist.
- Good adhesion to most materials: SMP products adhere to most substrates such as concrete, plastic and metal allowing for a wider variety of possible applications.
Looking for the perfect SMP adhesive or sealant for your project?
In case you are curious about what MS polymers and SPUR polymers can do to your project or product, or would like to enquire about a modified silane adhesive or sealant, do not hesitate to contact us. Our experts make sure your application gets the SMP system it deserves. Note that silane modified polymers are under continuous development and generally, easy to modify. Therefore, manufacturers usually are willing to collaborate with their customers to enable more uses of SMP systems.