Lacquers, emulsion paints and non-aqueous dispersions

This somewhat curious grouping needs an explanation. Although lacquers and emulsion paints involve completely different technologies, they are grouped together here because the leading examples of these types of paints dry by the same mechanism as defined in Chapter 7 lacquer dry. Non-aqueous dispersions must be dealt with alongside aqueous emulsions, since they are complementary. 

What is a lacquer It is a finish, clear or pigmented, which consists primarily of a hard linear polymer in solution. It dries by simple evaporation of solvents (lacquer dry). It is thus possible to make a lacquer from any soluble linear polymer, such as chlorinated rubber, 

These polymers are not wholly man-made (or synthetic), since they are based upon cellulose. This is not made, but found widely in nature, where it forms about half of all the cell wall material of wood and plants. Cotton is almost pure cellulose, and wood pulp is another source. 

The cellulose molecule consists of a large number of rings of atoms joined as shown  

At each comer of each hexagon (except where an oxygen atom is shown) a carbon atom should be imagined. It is omitted here to simplify the diagram. 

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