Tree resin obtained from the family Dipterocarpaceae
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
generaShorea 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.[1]
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.[citation needed]
Damar batu ('stone damar') is stone or pebble-shaped,
opaque dammar collected from the ground.[citation needed]
Damar hitam ('black damar')
Uses
Dammar varnish, made from dammar gum dissolved in
turpentine, was introduced as a picture
varnish in 1826;[2] commonly used in
oil painting, both during the painting process and after the painting is finished.[3] 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.[4]
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.[citation needed]
Encaustic paints are made from dammar crystals in beeswax with pigment added. The dammar crystals serve as a hardening agent.[5]
As caulk for ships in the past, frequently with pitch or bitumen.[6]
The gum is stable[citation needed], probably combustible and incompatible with strong oxidising agents. Its toxicity is low, but inhalation of dust may cause allergies.
Vateria indica (Dipterocarpaceae), source of white dammar in South Asia
References
^Scalarone, D.; Duursma, M.C.; Boon, J.J.; Chiantoire, O. MALDI-TOF mass spectrometry on cellulosic surfaces of fresh and photo-aged di- and triterpenoid varnish resins. J. Mass. Spec. 2005, 40, 1527-1535.
doi:
10.1002/jms.893