8/12/2019 Water Soluble Raft Agent
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Synthesis and Self-organization of Water Soluble (Meth)acrylic
Polymers
in Aqueous Media by Reversible Addition-Fragmentation Chain
Transfer (RAFT)
Murat Mertoglu1, Andr Laschewsky 1,21Universitt Potsdam,
Institut fr Chemie, P.O. Box 601553, D-14415 Potsdam, email:
[email protected]
potsdam.de, 2Fraunhofer Institute fr Angewandte Polymerforschung
FhG-IAP, Geiselbergstr. 69, D-14476Potsdam-Golm, email:
[email protected]
New chain transfer agents for free radical polymerization via
Reversible Addition-Fragmentation chainTransfer (RAFT) were
synthesized that are particularly suited for aqueous solution
polymerization (Figure 1).The new compounds bear dithioester and
trithiocarbonate moieties as well as permanently ionic groups to
confersolubility in water, independent of the solution pH. The
stability against hydrolysis was studied, and comparedwith the one
of the most frequently employed water-soluble RAFT agent
4-cyanopentanoic acid dithiobenzoate(CTA 1), using UV-Vis- and
1H-NMR spectroscopy. An improved resistance to hydrolysis was found
for thenew RAFT agents compared to the reference one, providing
good stabilities in the pH range between 1 and 8,and up to
temperatures of 70C. Controlled polymerization kinetics of
non-ionic, and ionic acrylic monomers,such as [(polyethyleneglycol)
methylether acrylate, (polyethyleneglycol)methylether methacrylate,
[2-(acryloyloxy)ethyl] trimethyl ammonium chloride, (3-acryloyloxy)
propansulfonate potasiumsalt, (3-methacryloyloxy) propansulfonate
potasiumsalt were studied in water at low temperatures relative
to
conventionally used polymerization temperatures (>60C ) RAFT
in order to prevent hydrolysis of end group.Further, diblock and
triblock copolymers of these acrylic polymers have been prepared
via RAFTpolymerization in water. These blocks are used to prepare
water soluble nanoparticles.
Figure 1. Examples for water-soluble RAFT agents and
(meth)acrylic monomers investigated.
References:1. Thang SH, Chong YK, Mayadune RTA, Moad G, Rizzardo
E. Tetrahedron Lett (1999) 40, 2435-24382. Baussard JF, Habib-Jiwan
JL, Laschewsky A, Mertoglu M, Storsberg J. Polymer (2004) 45,
3615-36263. McCormick CL, Lowe AB. Acc Chem Res (2004) 37,
312-325
C S
S
CHCH3
C O
NH
CH2
CH2
NaO3S
CH2
S
C
S
S
CH2
CH2
SO3Na
C S
S
C CN
CH2
CH2
COONa
CH3
C S
S
C CH3
C O
NH
CH2
CH2
SO3Na
CH3
C S
S
CHCH3
C O
NH
SO3K
KO3S
CH2 CH
C=O
O
CH2
CH2
O
CH3
n~8
CH2 C
CH3
C=O
O
CH2CH2
O
CH3
n~8
M1 M2
CH2 C
CH3
C=O
O
(CH2)3
SO3K
CH2 CH
C=O
O
(CH2)3
SO3K
M4 M5
H2C CH
C=O
O
(CH2)2
N+(CH3)3Cl-
M3CTA 1 CTA 2 CTA 4 CTA 5CTA 3
