«Фараби Әлемі» атты студенттер мен жас ғалымдардың халықаралық конференциясы
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SYNTHESIS OF HYDROPHOBICALLY MODIFIED POLYBETAINE
(HMPB)
Abutalip M.
Supervisor
:
PhD, Dr. Rakhmetullayeva R.K.
Al-Farabi Kazakh National University
abutalip.munziya@gmail.com
Hydrophobically modified polybetaine (HMPB) have received widespread
attention due to their smart response properties and
structures which resemble
biological polymers like peptides and DNA. However, few studies have focused on
the controlled synthesis and self- assembly of hydrophobically modified
polybetaines due to the difficulty of synthesizing these materials. In this work, we
reported the first molecular weight-controlled synthesis of amphiphilic
polybetaines with various hydrocarbons via the reversible
addition-fragmentation
chain- transfer (RAFT) polymerization approach.
We was synthesized poly (dodecyl-grafted aminocrotonate methacrylic acid)
(PACRO-MAA), poly (tetradecyl-grafted aminocrotonate methacrylic acid)
(PTACRO-MAA), and poly (hexadecyl-grafted amincrotonate methacrylic acid)
(PTACRO-MAA) via (RAFT) polymerization approach. The two different
tautomers of the monomer were also successfully identified and separated via thin
layer chromatography (TLC) and column chromatography, and chemical structures
of components of monomer products were characterized by Fourier Transform
Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR).
After successfully achieving the narrow molecular
weight distribution of
HMPB, the second goal is to study the self-assembly behaviors, FTRP and
13
C,
1
C -
NMR, combining with Gel Permeation Chromatography (GPC), were used for
characterizing polymer compositions and molecular weight profiles. High usage of
initiator/chain-transfer agent was preferable to reach a yield around 35%.
Molecular weight around 22000 - 50000 g/mol and a narrow molecular weight
distribution of 1.056-1.450 were achieved.
Spherical, rodlike, and fractal assembled structures for the poly (alkyl grafted
aminocrotonate -methacrylic acid) were observed with pH change using
Transmission Electron Microscopy (TEM), zeta sizer, and dynamic light scattering
(DLS). This change is consistent with ζ potential data
since the micelle structure
swells the most at basic pH and has a large electrostatic repulsion force.
The unique self-assembled structures of HMPCB synthesized via RAFT
provide an opportunity to understand fundamental
polymer science and can be
engineered for broad applications.
