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Why is it called living polymerization?

Why is it called living polymerization?

In polymer chemistry, living polymerization is a form of chain growth polymerization where the ability of a growing polymer chain to terminate has been removed. This can be accomplished in a variety of ways. Living polymerization: A chain polymerization from which chain transfer and chain termination are absent.

What is living anionic polymerization?

Living anionic polymerization is a living polymerization technique involving an anionic propagating species. Living anionic polymerization was demonstrated by Szwarc and co workers in 1956. Their initial work was based on the polymerization of styrene and dienes.

What is meant by living polymers?

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Living polymers are polymers that retain their ability to propagate and grow to a desired size while their degree of termination or chain transfer is still negligible.

How does living polymerization different from addition & condensation polymerization?

Addition polymerization results in homo-chain polymers whereas condensation polymerization results in hetro-chain polymers. The most significant difference is that in addition polymers there is no loss of atom. But in condensation reaction, there is a loss of a molecule of water, ammonia etc as a by-product.

What is the utilization of living polymerization?

What is the utilization of living polymerization? Explanation: Living polymerization enables the formation of block polymers by adding a fresh monomer to the reaction.

Is Atrp living polymerization?

Atom transfer radical polymerization (ATRP) is another common method of carrying out living polymerization. This method, like RAFT and other methods, sets up an equilibrium between a dormant phase of polymer chains and a growing phase.

What does anionic mean?

Definition of anionic 1 : of or relating to anions. 2 : characterized by an active and especially surface-active anion.

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How is the molecular weight distributed in the living polymers?

Such a polymer chain composition has a molecular weight distribution of 1.00, as the MWD is a quotient of the weight average molecular weight Mw and the number average molecular weight Mn. The higher the MWD value, the poorer is the uniformity of the polymer’s chain composition.

What is meant by suspension polymerization?

Suspension polymerization is a heterogeneous radical polymerization process that uses mechanical agitation to mix a monomer or mixture of monomers in a liquid phase, such as water, while the monomers polymerize, forming spheres of polymer.

Can cationic polymerization be living?

Living cationic polymerization is characterised by defined and controlled initiation and propagation while minimizing side-reactions termination and chain transfer. Initiation takes place by an initiation/coinitiation binary system, for example an alcohol and a Lewis acid.

Is free radical polymerization living?

Living free radical polymerization is a type of living polymerization where the active polymer chain end is a free radical. Several methods exist.

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What is the difference between ATRP and RAFT?

The main difference of RAFT with ATRP is that RAFT is based on the transfer of activity between polymer chains bearing dithioester moieties and not on the reversible deactivation of growing polymer chains. Mostly dithiocarbonyl derivatives are used as chain transfer agents.