The material selection platform
Adhesives Ingredients
The material selection platform
Adhesives Ingredients

Silane Modified Polymers (SMP): An Alternative to PU Polymers

Vladimyr Wolan – Apr 21, 2017

Silane Modified Polymers: An Alternative to PU PolymersPolyurethane polymers are very successful products used in the adhesive, sealants and paint industries. The hydrogen bonds present in PU bond add strength to the polymer matrix and are able to reform during sealant elongation. They also form a bond with a plasticizer for good adhesion to the surface.

However, the unreacted isocyanate groups in uncured PU sealants and adhesives are very reactive and harmful to humans in various forms.

Fortunately, chemists have developed a very good polymer design where, the nasty NCO group is eliminated, by a silane molecule. It’s a new polymer class that formulators of sealant and membranes need to be aware of.

Read on to know more about silane-modified polymers.

17 Comments on "Silane Modified Polymers (SMP): An Alternative to PU Polymers"
vladimyr W Nov 20, 2017
Dear Vasil Please contact sales@wolantech.com . We have Polymers that can make coatings that are isocyanate free, and we are getting shore A90 hardness, and pencil hardness of 6H. Solvent is difficult to eliminate but can be done .
Vasil L Nov 10, 2017
hello there, can we communicate with vladimyr regarding his silane/can be used as a substitute for hdi in top coat of 100micron/dft for 2k pu/1k pu?
vladimyr W Oct 3, 2017
Dear Apurba, Yes, you are correct that one part adhesives or sealants rely on moisture to pass through the cured material. A 35 mm thick sealant joint would be a problem, and I suggest the profile is not the correct one for the application. There are times when a 2 part adhesive or sealant needs to be used.
Apurba M Aug 31, 2017
Curing rate is also an issue as sealing compound. we tried a depth of 35 mm and found the material remained soft below 20 mm in 7 days. Higher catalyst may solve the problem at the cost of UV resistance.
vladimyr W Jun 9, 2017
Dear Darmesh, The SPUR silane terminated polyurethanes have some urea groups, and viscosity is high . Our Polymers use some patented additives to reduce the hydrogen bonding in the Polymer to have a workable product. Our DMS10000 Polymer is methyl dimethoxy silane terminated . The Polymer can be processed with wet PCC and GCC. The big advantage is that with the hydrogen bonding available, plasticizing with DIDP or Mesamoll is no problem, and the plasticizer does not leach.
Dr. Dharmesh D Jun 2, 2017
What about the adhesion performance between STPE (Silan Terminated Polyether) Vs. SPUR (Silan Terminated Polyurethane) on different substrates? What is the advantage of SPUR over STPE / MS ?
Dr. Dharmesh D Jun 2, 2017
I would like to know the difference between STPE (Silan Terminated Polyether) Vs. SPUR (Silan Terminated Polyurethane).
Alberto P Jun 1, 2017
So, dear colleagues, could you show me some formulations (That They work!) of S'PUR type? Thanks
vladimyr W May 23, 2017
Dear Roberto, these issues are known and formulation methods and additives are used to minimise the alkali and UV attack on SMP Polymers, which also affects most organic polymers. High catalyst levels in some of these formulations is a cause for UV attack, as are the commonly used PU polymers. The trimethoxy silane terminated polymers, as well as the alpha silane Polymers use very little or no catalyst and have excellent exterior performance .
roberto m May 20, 2017
SMP, nucleophilic attack of silicon and depolymerization phenomena in sealants and adhesives. These phenomena have caused controversy, civil and criminal cases like windscreens that are detached while the car is traveling. Many sealants manufactured with the famous raw mnaterials "genio-sil" (or somethings like that, an smp technology, and other famous brands) have depolymerized after few month or and 5 years after exposure at outdoor environment or on alkaline substrates such as portland cement. So, an elastic and tough elastomer turns into a plastic and sticky gum similar to a chewing gum. The problem arises, even when the indication of the raw material producer is respected. I think that we must pay attention to the problems of nucleophilic attack of silicon and act with specific molecules to cancel this depolymerization effect. It is sufficient to add from 0.5 to 1% of specific molecules.

1 2
Leave a comment

Your email address and name will not be published submitting a comment or rating implies your acceptance to SpecialChem Terms & Conditions
Improve your performance with water soluble epoxy compounds
Naphthenic Oils For Better Adhesion
Back to Top