This coatings have been manufactures by alkyd resins.
Alkyd resins are prepared from polyols, dibasic acid, and fatty
acids. The term alkyd is derived from alcohol and acid.alkyds
Comparison of some unsaturated C18 fatty acids. The C=C bonds
are chemical groups which react with oxygen and change the liquid oil to a
Typical polyester reaction
A theoretical alkyd prepared from 1 mol each of glycerol, PA,
and fatty acid would have an oil length of about 60.
Glycerol-Phthalic Anhydride-Fatty Acid Alkyd Resin
There are many type classification of alkyd.one classification
is based on oil length of an alkyd .oil length of an alkyd is calculated by
dividing the amount of "oil" in the final alkyd by the total weight of the alkyd
Classification and properties of Alkyds by Oil Length
Alkyds General Properties