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Shellac

Shellac is a secretion of the lac insect Coccus lacca, found in the forests of Assam and Thailand. Freed from wood it is called "seedlac."

Shellac is a natural polymer and is chemically similar to synthetic polymers, thus considered a natural plastic. It can be molded by heat and pressure methods, so it is classified as thermoplastic.

A XIXth century picture frame made of shellac.

It was used from mid XIXth century on to produce small goods like picture frames, boxes, toilet articles, jewellery, inkwells and even dental plates.

It is soluble in alkaline solutions such as ammonia, sodium borate, sodium carbonate, and sodium hydroxide, and also in various organic solvents.

When dissolved in acetone or alcohol, shellac yields a varnish of superior gloss and hardness. Orange shellac is bleached with sodium hypochlorite solution to form white shellac.

Shellac was also used in the production of gramophone records until ca. 1950. See gramophone record for details.

It is now considered obsolete as a moulding compound, having very few applications.

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