Dammar gum

File:Dammar.jpg

Dammar resin

Dammar, also called dammar gum, or damar gum, is a resin obtained from the tree family Dipterocarpaceae in India and Southeast Asia, principally those of the genera Shorea or Hopea (synonym Balanocarpus). The resin of some species of Canarium may also called dammar. Most is produced by tapping trees; however, some is collected in fossilised form on the ground. The gum varies in colour from clear to pale yellow, while the fossilised form is grey-brown. Dammar gum is a triterpenoid resin, containing many triterpenes and their oxidation products. Many of them are low molecular weight compounds (dammarane, dammarenolic acid, oleanane, oleanonic acid, etc.), which easily oxidizes and photoxidizes.

Source and harvesting

Gum damar is a natural resin derived from various species of the genus Shorea, primarily found in Indonesia and other parts of Southeast Asia. It is obtained by tapping the trees, which exude small globules or "tears" of resin that harden upon contact with air. These resin tears are collected manually and processed by local harvesters.

Modern applications

While gum damar has long been used in traditional varnishes, incense, and as a component in batik, recent developments have expanded its use into eco-conscious markets. The resin is now incorporated into natural candle-making, sustainable fragrances, biodegradable industrial materials, and plant-based cosmetic formulations.

Types

• Damar mata kucing ('cat's eye damar') is a crystalline resin, usually in the form of round balls. Shorea javanica is an important source in Indonesia.
• Damar batu ('stone damar') is stone or pebble-shaped, opaque dammar collected from the ground.
• Damar hitam ('black damar')

Uses

• Dammar varnish, made from dammar gum dissolved in turpentine, was introduced as a picture varnish in 1826; commonly used in oil painting, both during the painting process and after the painting is finished. Dammar varnish and similar gum varnishes auto-oxidize and yellow over a relatively short time regardless of storage method; this effect is more pronounced on paintings stored in darkness than with works on display in light due to the bleaching effects of sunlight on the colorants involved.
• Batik is made from dammar crystals dissolved in molten paraffin wax, to prevent the wax from cracking when it is drawn onto silk or rayon.
• Encaustic paints are made from dammar crystals in beeswax with pigment added. The dammar crystals serve as a hardening agent.
• As caulk for ships in the past, frequently with pitch or bitumen.
• As a common mounting material along with canada balsam for preparing biological samples for light microscopy.
• Used in Ayurvedic medicine for various conditions.

Constituent compounds

Fresh dammar gum consists of a mixture of compounds; primarily hydroxydammarenone, dammarenolic acid, and oleanonic aldehyde.

Material safety

Physical data

• Appearance: white powder
• Melting point: around 120 °C
• Density: 1.04 to 1.12 g/ml
• Refractive index: around 1.5
• CAS number: 9000-16-2
• EINECS: 232-528-4
• Harmonised Tariff: 1301-90

Stability and toxicity

The gum is stable, probably combustible and incompatible with strong oxidising agents. Its toxicity is low, but inhalation of dust may cause allergies.

See also

• Agathis (Araucariaceae), synonym Dammara
• Canarium strictum (Burseraceae), source of black dammar in South Asia
• Kauri gum, from Agathis australis
• Shorea hypochra (Dipterocarpaceae), source of dammar temak
• Shorea robusta (Dipterocarpaceae), source of sal dammar
• Vateria indica (Dipterocarpaceae), source of white dammar in South Asia