However, the certain properties of NR can be improved via chemical modifications at the carbon-carbon double bonds (C=C) in its isoprene unit
to produce functionalized specialty rubbers with an expanded range of physical and chemical properties.
The bromine atom, in most cases, is attached to one of the allylie carbon atoms in the isoprene unit
Broadly, phytochemicals may be classified as: terpenoids (considered the largest group of naturally occurring compounds that are basically derived from five-carbon isoprene units
), phenolic compounds (that contain one or more phenol groups), glucosinolates (that contain sulphur and nitrogen and are derived from glucose and an amino acid), organic acids, carbohydrates, etc.
In case of GR composites, GR layers are well exfoliated through ENR matrix and the particle size is smaller compared to GT filled composites, It is because of the good compatibility between oxygen functionalities on the surface of GR and epoxy groups of isoprene units
owing to the formation of hydrogen bonds, the exfoliated GR layers were indicated through arrow marks in TEM micrographs.
Terpenes structures are consisting of isoprene units
(C5), which may contain oxygen.
In humans, dolichol-19, containing 19 isoprene units
, is the most abundant species.
Now it became clear that the secret of synthetic rubber lay in joining together isoprene units
into long chains.
Coenzyme Q10 is liposoluble and has 10 isoprene units
. It exists in nature and in the body in two forms: the oxidized form, called ubiquinone, and the reduced form, ubiquinol.
Their chemical structure consists of repeated isoprene (C5H8) units and is classified according to the number of isoprene units
: Monoterpenes have two isoprene units
(C10), sesquiterpenes have three (C15), and diterpenes have four (C20).
The splitting pattern obtained in the NMR spectrum suggested the compound to be an open-chain terpene bearing many isoprene units
The ubiquinone found in humans, ubidecaquinone, has 10 isoprene units
(a total of 50 carbons), ergo, the "10" in CoQ10.
Natural rubber is a polyisoprene produced by Hevea trees and consists of approximately 99% cis-l,4 repeating isoprene units
. Drawbacks of NR, including odor and adverse allergic (Type 1) reactions, led to the development of synthetic alternatives.