Sciencemadness Discussion Board

Alkyd "oil content"

stygian - 11-5-2008 at 18:44

Being oil-derived I guess this is the right place.

How exactly are short, medium, and long oil content determined with these resins? After the initial alcoholysis, there should be no oil left, unless more is added at a later point as a simple mixture. This has me a bit confused.

JohnWW - 11-5-2008 at 19:36

The answer may be in Luthria's "Oil Extraction & Analysis", which I have uploaded to rapidshare.com, and of which I posted the downloading link in the Organic Chemistry thread of the References section. If you cnnot find the link, I will send it to you privately.

not_important - 11-5-2008 at 19:37

SFAIK the oil content is determined at time of manufacture, by how much oil or fatty acid is added. Oil content is sometimes given as weight percent of oil mixed into the polyester, other times as the three classes as you listed, with short having the least percentage of oil/fatty acid. Again, this is a measurement done prior to mixing and reacting, not a measurement of the finished resin except as what percent of its weight is derived from the raw ingredient oils.

As an aside, not all the oil/fatty acid gets bound up into the polyester, some small amount remains free as it is not economical to force full esterfication. However, as these are drying oils most of the free oil/fatty acid ends up cross-linking with their esterfied compatriots.

stygian - 12-5-2008 at 19:07

Quote:
Originally posted by JohnWW
The answer may be in Luthria's "Oil Extraction & Analysis", which I have uploaded to rapidshare.com, and of which I posted the downloading link in the Organic Chemistry thread of the References section. If you cnnot find the link, I will send it to you privately.


This would be appreciated. I do not have access to the references section (how does one get access? I've been quite inactive and honestly haven't even tried to)