Semi-drying oils

Properties:

• dries slower,
• after drying, the coating loses a lot of specific gravity,
• tendency to soften again (syneresis),
• the dried coating melts and dissolves in organic solvents.

Semi-drying oils include:

• poppy,
• sunflower,
• soybean,
• peanut.

The oil consists of glycerol esters of various fatty acids. Saturated acids are present in small amounts (15%).
The predominant fatty acids are unsaturated, such as:

• oleic acid,
• linoleic acid,
• linolenic acid,
• eleostearic acid.

Significant differences in the structure and chemical composition of individual drying oils consist primarily in the different combination of unsaturated fatty acids. Mainly on the presence of a fatty acid with a different number of double bonds.
Differences in drying oils occur depending on the combinations of saturated acids they contain.