solvents

Xylene, Toluene, Styrene and MEK are they all solvents? When to use each and are they exclusively for polyester resins/products, 10% of any is a good basic guideline?

tks

 

Yes they are solvents and no they aren't used exclusively for polyester resin products.

As to 10% being a good basic guideline, this question is so unspecific that it can't be answered. Generally, chemistry is considerably more precise.

As to when to use these chemicals again the question is grossly unspecific and unanswerable.

You need to supply specific applications or processes where the chemicals and then possible ratios can be offered.

 

Xylene is an alcohol. Toluene an aromatic hydrocarbon. MEK is related to acetone. They are all solvents, but not all dissolve the same substances. Styrene and MEK both work well with polyester. However, you are better off asking the manufacturer or reading the spec sheets for the preferred solvent.

 

The short answer to the 10% question.... there is almost no situation where a manufacturer will recommend 10% of any of these to be added to any of their normal products.

The reason. Polyesters are formulated to have a specific amount of monomer (type of solvent...typically styrene), adding more can mess with the chemistry and degrade the product, sometimes dramatically. Many people like to play chemist thinking they are much smarter than those with decades of experience and degrees to back them up.

 

I miss isopropyl alcohol and methylene chloride in this list. Also nice solvents...

Anyhow, be careful with all solvents. They make you forget things. Although my grandfather (house painter) became 89 years old and died while I was 25, he never knew me...

 

Thanks for the replies, I've only needed to thin bog used to fair plugs, so nothing critical so far.

I've seen epoxy resins advertised as 100% solids but not polyester/vinyl, should I expect/request this % info?

Does a higher or low % of styrene (monomer) mean a better resin?

 

Epoxy and polyester use very different chemistry, so don't try to compare them in that way.

% of Styrene can affect the performance of polyester resins. For decades these resins were formulated with the % of styrene that yielded the best handling and performance characteristics, with the emission regulations that have been put in place requiring less styrene, certain characteristics of some resins resin are altered. Styrene is a key component of a polyester resin and aids in the cure. Straight ORTHO, ISO and VE resins typically work best with a styrene content in the 40-50% range, with the current 35% styrene content required in most of North America (you can get around this for specialty applications), it sort of takes these resins out of the usable range for many applications. DCPD based resins require far less styrene so they are frequently blended with ORTHO, ISO and VE resin to meet the 35% regulation.

"Does a higher or low % of styrene (monomer) mean a better resin?"

Not really, the manufacturer formulates the resin to perform at a certain % and each resin may be different depending on the base used and its intended application, plus meet local or regional emission regulations. This applies to each resin whether its formulated to meet emission regulations or not.