What is the right sealing system for your tank or silo?

Durable seals are an important part of the construction or renovation of tanks and silos.
Various aspects play a major role in the choice of the right sealing material. These could include:

  • the (chemical) content of the tank
  • the composition of the walls and bottom, including the finish (e.g. coating)
  • the ambient temperature
  • the temperature in the tank
  • the certification requirements
  • the durability
It is also important that the sealing system is both safe and easy to transport and easy to work with.
So what is the best sealing material?

The differences between MS polymer and polyurethane-based sealing technologies

This document provides a more in-depth discussion of two sealing technologies used in the tank construction sector: sealants based on MS polymer (MSP) and sealants based on polyurethane (PU). We clearly set out the main differences, with information on the bonding properties, the elasticity and the safety. After reading this document you will have more background information and clarity about the differences between these technologies and are able to select the right sealing system for your specific tank.

Request your whitepaper

Sealing systems based on MS polymer or polyurethane

Both MSP and PU technologies are permanently elastic and have good bonding properties. They both react to moisture, forming a strong and flexible network. This makes these sealing technologies highly suitable for absorbing motion and vibration.

Application possibilities

Movable joints can be sealed well with both technologies. MSP and PU sealants are also suitable in situations where materials with different thermal expansion coefficients need to be sealed. On this basis, therefore, both technologies can be applied for durable sealing of tanks or silos.

The differences

Although at first glance, MSP and PU sealants appear to have many similar properties, there are clear differences in the basis of the two technologies. For example, MSP contains reactive silane/silyl groups that provide for the curing. PU systems contain reactive isocyanate groups for curing.

Silane versus isocyanate

The curing reaction based on silane (MSP system) has fewer or no undesirable secondary reactions under the influence of moisture. This is in contrast to material containing isocyanate (PU system), which will foam or blister in a moist environment. This is because carbon dioxide is released during curing, which leads to deterioration in the properties of the material. Another disadvantage of PU sealants is that contact with isocyanates is possible during application, particularly during the finishing process: these chemicals constitute a health risk. In short, a label-free MSP is safer during application. This sealant can also be applied in less favorable (moist) conditions.


Request whitepaper