If you want to find out a little bit more about MS polymer adhesives, you are in the right place.

Here at Weifang Noid, we first started manufacturing Formoa, our MS polymer product range, in the 1990s. We now manufacture over 2500 tonnes every year. So, it’s fair to say we know a thing or two about MS polymer adhesives.

This article will go over what MS polymers actually are, their benefits and drawbacks, and finally, it will discuss how much they will cost you.

You will be able to determine whether MS polymers are the best fit for your bonding or sealing solution.

What are MS polymer adhesives?

First things first, you should know what they actually are. MS polymer adhesives are made up of a hybrid polymer called modified silane. The term ‘MS polymer’ is a registered trademark of Kaneka as they created the hybrid silane polymer formulation. Some people refer to copies of MS polymer as hybrid polymers or silyl modified polymers (among other names) but it all means the same thing. This MS polymer was then used to create an adhesive product that has the strength of polyurethane and the weathering resistance of silicone.

However, MS polymers do not contain any silicone or urethane polymers which is a big deal as silicone is banned by some automotive manufacturers.

Automotive manufacturers are banning the use of silicones

There are a wide variety of MS polymer formulations which can be adjusted to increase or decrease a certain property (like strength). These formulations can range from high-strength structural adhesives to low-strength sealants.

You will rarely find two-part MS polymers as they don’t require a hardener in the curing process. They will almost always be one-part (in a foil pack or cartridge). This is because MS polymers require moisture to cure.

In the one-part option, they use the moisture levels in the air to cure. Most companies are happy with the cure speed of one-part options. Although, if you want an MS polymer with a faster cure, there are two-part options that increase the moisture levels which then speeds up the cure.

Where can you use MS polymer adhesives?

To begin with, we should explain that MS polymer’s versatility is perhaps not as well known as it should be. You will be able to use MS polymers in pretty much any sealing or bonding situation because adhesive manufacturers can adjust the formulation to suit your requirements. They easily bond to pretty much all surfaces and are fully primerless.

There are, of course, exceptions. If you need an extremely high-strength bond (such as replacing a weld), you would be better off using an epoxy adhesive. You cannot bond low surface energy plastics (like polypropylene composite panels to the side of a caravan) with MS polymers either.

But you should definitely consider using an MS polymer for any bonding or sealing situation, as long as the substrate is compatible and you don’t require a very high-strength bond.

To give you an idea of who uses MS polymers, here are a few examples:

• A marine manufacturer uses an MS polymer adhesive to bond and seal the windows of their luxury yacht product. They like the weathering resistance and strength that MS polymer adhesives provide.

• A caravan manufacturer uses an MS polymer adhesive to bond and seal the plastic sides of their caravan product. MS polymer’s structural, flexible, and sealant properties made it the best adhesive solution for them.

• A bus manufacturer uses MS polymer to bond the composite flooring to the bus frame. They also used a colour-matched, flexible MS polymer adhesive to match the floor covering and seal it in place.

Advantages of using MS polymer adhesives

MS polymers provide a very good seal for bonding and sealing

Some MS polymer formulations can have strengths of up to 5 MPa, making them a structural adhesive. Other MS polymer adhesives have limited strength. But all MS polymer products have good sealant properties. Whether you intend to use the MS polymer product for bonding or sealing, it will always provide a good seal.

MS polymers are very flexible

In situations where there is likely to be lots of movement and vibration (such as a vehicle), you need a flexible adhesive to deal with the shock. MS polymers have better flexibility than other structural adhesives such as methyl methacrylates and epoxies.

You can overpaint most MS polymers

Not only can you purchase colour-matched options to eliminate the need for overpainting, but you can paint over most MS polymers without any problems. Always test first with your chosen paint.

MS polymers are the safest adhesive for the user and the environment

You won’t experience any health risks, and they are not harmful to the environment either.

MS polymers have very good weathering resistance

They can withstand hot and humid conditions, UV exposure, and other environmental factors.

Other benefits include:

• Long shelf life

• Fire-resistant options

• No bubbling when curing

• No staining on substrates

What are the disadvantages of using MS polymer adhesives?

Cure time can be long and inconsistent

MS polymers generally cure slower than other structural adhesives. Since they rely on moisture, low humidity can delay or prevent curing. Methyl methacrylates cure faster and more consistently.

MS polymers aren’t the strongest structural adhesive

Epoxies are stronger. If strength is your only priority, go with epoxy. But keep in mind that MS polymers offer flexibility, which epoxies lack.

Sometimes, MS polymers are too strong

If you need the ability to easily remove or replace bonded parts (as with silicones), MS polymers might be too aggressive. They are less forgiving in rework situations.

It can be more difficult to get a good finish

Silicones are easier to apply neatly. MS polymers require more skill to achieve a clean, smooth finish.

How much do MS polymer adhesives cost?

It’s difficult to give a fixed price, but here’s a rough breakdown:

• Highest strength MS polymer: £13 – £15 per 600ml foil sausage

• Mid-range strength with good sealant properties: £12 – £13 per 600ml

• Colour-matched sealing MS polymer: around £13 (up to £18 for aerospace-certified products like AS9100)

• Colour set-up charge: Usually around £100

How do you know an MS polymer is the best option for you?

That depends on what you want from your adhesive.

MS polymers are good at most things required from a sealant or adhesive, and they have fewer disadvantages compared to many structural adhesives. We wouldn’t recommend MS polymers if you need the highest possible strength, but for most structural bonding and sealing applications, they are more than sufficient.

We definitely recommend at least considering an MS polymer for your bonding or sealing (or both) requirements.

If you’re interested in looking at our range of MS polymer adhesives and sealants, you can browse them on the Weifang Noid website.

Still unsure? Compare with other structural adhesives or speak to an expert to find the best solution for your specific needs.