Understanding cycloaliphatic Concrete Epoxy Floor Coatings!
Introduction:
In the 50 or so years that epoxies have been in existence, one of the technological advances was the introduction of cycloaliphatic curing agents ten or twenty years ago. For many years it was the 'secret weapon' of epoxy formulators. The addition of cycloaliphatic curatives in the Part B (hardener or curing agent) of epoxy resin systems greatly improves the epoxy. Usually the Part B is a blend of curing agents selected due to properties and/or price. Generally, cycloaliphatic curing agents (and their are several) are more expensive than the regular/standard curing agents. Benefits of Cycloaliphatics: Cycloaliphatics are known for their:
The ring structure (the 'cyclo' part) also provides (in many cases) a bit more structural 'stretch' than the traditional straight chain curing agent. This provides for better 'impact' resistance (note: 'hard' epoxies, on the other hand, offer better abrasion resistance). The benefits and higher quality of cycloaliphatic epoxies becomes more obvious if you perform an internet search for "cycloaliphatic epoxy". You'll find nearly all the search results refer to cycloaliphatic epoxy electrical insulators in comparison to traditional ceramic glass insulation. You'll find, after a bit of reading, that the insulator industry likes the long lasting, weatherability of cycloaliphatic epoxy insulators and think them suitable for long term outdoor exposure. There is no mention of non-cycloaliphatic epoxies. The conclusion is that the most or all of the top grade, exterior quality, high performance epoxies use a Part B curing agent blend consisting partially of cycloaliphatics. Thus, checking the MSDS of the Part B side of an epoxy product for mention of cycloaliphtics is a good way to judge the quality and performance of the epoxy (just like epoxies with a necessary induction time are often low end epoxies - visit our Epoxy 101 web site www.epoxyproducts.com/25points4u.html ). Cycloaliphatic chemistry explained by "The Chemist" - the hands-down expert on epoxies - in a 2/18/03 post on the Wooden Boat Forum -- "The cycloaliphatic structure refers to a six-member carbon-atom ring in the backbone of the curing agent instead of carbon-carbon linkages between amines in some other curing agents such as West or Sys. 3. The cycloaliphatic curing agents have the amine groups connected to the rings. Both use Diglycidyl ether of Bisphenol-A as the major component of the epoxide curing agent, and both contain benzyl alcohol, a volatile plasticizer which acts as a molecular lubricant and facilitates curing [although systems with cycloaliphatic curing agents contain much more, typically 20-30%, as they simply do not cure more than about half-way at room temperature without it. While the cycloaliphatic ring is resistant somewhat to Uv degradation, more that the carbon-carbon linkages between amines in some other types of curing agents, both contain the aromatic ring structure of diglycidyl ether of Bisphenol-A, which breaks down fairly readily on UV exposure, and both contain amines; these give both molecular breakdown and yellowing all by themselves. None of these structures should be considered UV-stable, even though the cycloaliphatic structures are better than the aliphatic amine-structures in that regard." Now that you know about cycloaliphatic epoxy curing agents, you should also know about the use of nonyl-phenol www.epoxyproducts.com/nonyl4u.html in epoxies as well.
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