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Living free radical polymerization is a type of living polymerization where the active polymer chain end is a free radical.Several methods exist. IUPAC recommends [1] to use the term "reversible-deactivation radical polymerization" instead of "living free radical polymerization", though the two terms are not synonymous.
Living polymerization: A chain polymerization from which chain transfer and chain termination are absent. Note : In many cases, the rate of chain initiation is fast compared with the rate of chain propagation, so that the number of kinetic-chain carriers is essentially constant throughout the polymerization.
The nature of chain transfer reactions is currently well understood and is given in standard polymerization textbooks. Since the 1980s, however, a particularly active area of research has been in the various forms of free radical living polymerizations including catalytic chain transfer polymerization, RAFT, and iodine transfer polymerization ...
Reversible Addition-Fragmentation Chain-Transfer Polymerization (RAFT): requires a compound that can act as a reversible chain-transfer agent, such as dithio compound. [2] Stable Free Radical Polymerization (SFRP): used to synthesize linear or branched polymers with narrow molecular weight distributions and reactive end groups on each polymer ...
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.
The expression ‘controlled radical polymerization’ is sometimes used to describe a radical polymerization that is conducted in the presence of agents that lead to e.g. atom-transfer radical polymerization (ATRP), nitroxide-(aminoxyl) mediated polymerization (NMP), or reversible-addition-fragmentation chain transfer (RAFT) polymerization.
In chain growth polymerization, two growing chains can collide head to head causing the growth of both of the chains to stop. In the case of radical or anionic polymerization , chain transfer can occur where the radical at the end of the growing chain can be transferred from the chain to an individual monomer unit causing a new chain to start ...
In polymer chemistry, degenerative chain transfer (also called degenerate chain transfer) is a process that can occur in a radical polymerization where the active site is transferred from one site along the polymer chain to another site, without changing the active site's reactivity (hence the term "degenerate," signifying that the pre- and post-transfer active sites have the same energy or ...