Resins and Their Basic Properties
Resins are natural or synthetic (manmade) organic compounds that come in the form of noncrystalline liquid. In other words, the structure is different from that crystals, because they do not have a fixed order of molecules and atoms.
Natural resins are often found in natural gas, oil, and plants and are brown or yellow in color. On the other hand, synthetic resins have and imitate the characteristics of natural resins but are chemically different. Resins can be either thermoplastic and thermosetting (refer to my previous article on plastics to know more about this). Most importantly, resins are flammable and are not soluble in water. These two properties lead to the common usage of resins, which are the following:
- adhesives (i.e. glue)
- varnishes (i.e. floor varnish)
- food glazing
Terpenes in Natural Resins
Terpenes are hydrocarbons make up resins and can be found in the bodies of most living organisms. In plants, terpenes are found in high concentrations and help the plants to protect themselves from factors of the external environment.
Terpenes can be extracted from the plants through the means of vaporization. This is because terpenes can be easily evaporated. Scientists describe this using the “volatile”. So because resins are easily evaporated, they are able to emit a fragrance.
Varnish is protective liquid made up of resins, oils, and alcohols. In the past, people found out that by coating the floor with varnish, the floor would then be free from water damage or other tears. The varnish would also make the surface appear glossy and shiny. Not only does varnish contain resin, they also contain a “drying oil” that helps to speed up the drying process.
Perfumes and Incense
In the past, natural resins like myrrh, frankincense, agarwood, pine, and balsams were used to make perfumes and incense. As these were burnt, the resin would let out a sweet scent.
These incense and perfumes would then be used for religious or medical purposes which still exist until today. As an example of a religious use would be how the Ancient Egyptians used oils and incense to make the dead have a sweet smell before burying them in tombs. As for medical purposes, scented incense can be used to reduce stress and anxiety, and can accelerate a body’s healing process.
Learn more at:
National Geographic books