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A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
The addition−fragmentation chain-transfer process was first reported in the early 1970s. [3] However, the technique was irreversible, so the transfer reagents could not be used to control radical polymerization at this time. For the first few years addition−fragmentation chain-transfer was used to help synthesize end-functionalized polymers.
A classic example of NGP is the reaction of a sulfur or nitrogen mustard with a nucleophile, the rate of reaction is much higher for the sulfur mustard and a nucleophile than it would be for a primary or secondary alkyl chloride without a heteroatom. [4] Ph−S−CH 2 −CH 2 −Cl reacts with water 600 times faster than CH 3 −CH 2 −CH 2 ...
Polymer chemistry is a sub-discipline of chemistry that focuses on the structures, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are also applicable through a wide range of other chemistry sub-disciplines like organic chemistry , analytical ...
For example, if the atom bearing the positive charge is stabilized by electron-donating groups, polymerization will proceed by the S N 1 mechanism. [20] The cationic species is a heteroatom and the chain grows by the addition of cyclic monomers thereby opening the ring system. Synthesis of Spandex. [22]
In chemistry, catenation is the bonding of atoms of the same element into a series, called a chain. [1] A chain or a ring may be open if its ends are not bonded to each other (an open-chain compound), or closed if they are bonded in a ring (a cyclic compound). The words to catenate and catenation reflect the Latin root catena, "chain".
In polymer chemistry, branching is the regular or irregular attachment of side chains to a polymer's backbone chain. It occurs by the replacement of a substituent (e.g. a hydrogen atom ) on a monomer subunit by another covalently-bonded chain of that polymer; or, in the case of a graft copolymer , by a chain of another type.
The side chain is a hydrocarbon branching element of a molecule that is attached to a larger hydrocarbon backbone. It is one factor in determining a molecule's properties and reactivity. [2] A side chain is also known as a pendant chain, but a pendant group (side group) has a different definition.