Comparison between ATRP and RAFT polymerization

ATRP and RAFT polymerization techniques are both capable to synthesize polymers with controlled average molecular weights, molecular weight distributions, and structures. In addition to that, they are beneficial to polymerize acrylic monomers and styrene monomers which are easy to synthesize functional monomers and applicable to conventional free radical polymerization.

	ATRP	RAFT Polymerization
Reagents	ATRP initiators Ligands Transition metal catalysts	RAFT agents (chain-transfer agent，CTA) Radical initiators
End groups
End groups removal	Mainly for improving stability of resultant polymers nBu3SnH,4) Pd/C and H2,5) 10-Phenylphenothiazine and lights,6) etc. are used.	Mainly for removing color and odor of resultant polymers Radical induced reduction, radical addition-fragmentation-coupling, thermolysis, photo-reduction using 10-Phenylphenothiazine, etc.6,7,8)
End groups functionalization	Ref. 9, 10 e. g.)	Ref. 7, 8 e. g.)
Polymerization in aqueous media	Challenging	Applicable
Acidic monomers	Unfavorable	Applicable
pH	Not applicable in low-pH because of protonation of ligands	Not applicable in high-pH because of degradation of RAFT agents
Oxygen tolerance	Although conventional method has no oxygen tolerance, several oxygen tolerant ATRPs have been reported.11)	PET-RAFT polymerization is known as oxygen tolerance method.12)
Other advantage	Generally coloring is not problematic without end group removal/fuctionalization.	Because RAFT is performed just adding RAFT agent to free radical polymerization system, existing facilities for free radical polymerization might be applied.

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Common ATRP initiators, ATRP ligands, RAFT agents appropriate to each monomers

The table below shows representative ATRP and RAFT reagents used to polymerize acrylates, acrylamides, methacrylates, and methacrylamides, which are frequently used by materials scientists and life scientists.
Careful selection of initiator and ligand for ATRP, and careful selection of RAFT agent according to monomer structures are required for achieving sufficient control.

Typical examples for ATRP

Monomer	Reference	ATRP initiator	ATRP ligand	Catalyst
Acrylates	Ref. 13
Acrylamides	Ref. 16
Methacrylates	Ref. 18
	Ref. 19
Methacrylamides	Ref. 22

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Typical examples for RAFT polymerization

Monomer	Reference	RAFT agent (CTA)	Radical initiator
Acrylates	Ref. 14
Acrylamides	Ref. 15 a	or
Acrylamides	Ref. 17
Methacrylates	Ref. 20
	Ref. 21
Methacrylamides	Ref. 20

^a oxygen induced polymerization

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Products for ATRP

ATRP initiators

You can see other ATRP initiators in the below link.

• Initiators [Atom Transfer Radical Polymerization (ATRP) Reagents]

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ATRP ligands

You can see other ATRP ligands in the below link.

• Ligands [Atom Transfer Radical Polymerization (ATRP) Reagents]

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Transition Metal Catalysts

You can see other transition metal catalysts in the below link.

• Transition Metal Catalysts [Atom Transfer Radical Polymerization (ATRP) Reagents]

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Products for RAFT polymerization

RAFT agents (CTA)

You can see other transition metal catalysts in the below link.

• Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization Reagents

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