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Natural bitumen pitch, from the tar pit above the McKittrick Oil Field, Kern County, California. Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum, coal tar, [1] or plants. Pitch produced from petroleum may be called bitumen or asphalt, while plant-derived pitch, a resin, is known as rosin in its solid ...
Rosin (/ ˈ r ɒ z ɪ n /), also known as colophony or Greek pitch (Latin: pix graeca), is a resinous material obtained from pine trees and other plants, mostly conifers. The primary components of rosin are diterpenoids, i.e., C 20 carboxylic acids. Rosin consists mainly of resin acids, especially abietic acid. [1]
The polysaccharide components of plant cell walls are highly hydrophilic and thus permeable to water, whereas lignin is more hydrophobic. The crosslinking of polysaccharides by lignin is an obstacle for water absorption to the cell wall. Thus, lignin makes it possible for the plant's vascular tissue to conduct water efficiently. [15]
There is a tendency to use "tar" for more liquid substances and "pitch" for more solid (viscoelastic) substances. [2] Both "tar" and "pitch" are applied to viscous forms of asphalt, such as the asphalt found in naturally occurring tar pits (e.g., the La Brea Tar Pits in Los Angeles).
Carbon fiber is often time produced using two main methods: through the use of Polyacrylonitrile (PAN) and from pitch. [1] [2] [3] Pitch is a viscoelastic material that is composed of aromatic hydrocarbons. Pitch is produced via the distillation of carbon-based materials, such as plants, crude oil, and coal.
A resin is a solid or highly viscous liquid that can be converted into a polymer. [1] Resins may be biological or synthetic in origin, but are typically harvested from plants. Resins are mixtures of organic compounds, and predominantly terpenes. Well known resins include amber, hashish, frankincense, myrrh and the animal-derived resin, shellac.
Birch bark tar use as an adhesive began in the Middle Paleolithic. Neanderthals produced tar through dry distillation of birch bark as early as 200,000 years ago. [6] A 2019 study demonstrated that birch bark tar production can be a simpler, more discoverable process by directly burning birch bark under overhanging stone surfaces in open-air conditions. [7]
Chemically, gutta-percha is a polyterpene, a polymer of isoprene, or polyisoprene, specifically (trans-1,4-polyisoprene). [3] The cis structure of polyisoprene is the common latex elastomer. [3] While latex rubbers are amorphous in molecular structure, gutta-percha (the trans structure) crystallizes, leading to a more rigid material. It exists ...