4th EucheMs chemistry congress

Poster Session 1
s1104
chem. Listy 106, s587–s1425 (2012)
Poster session 1 - organic chemistry
P - 0 4 8 5
PoLy(ethyLene)-GrAft-PoLy(tert-ButyL
ACryLAte) viA AtoM trAnSfer rAdiCAL
PoLyMerizAtion: funCtionAL PoLyoLefinS
froM PoLyBroMinAted ALKAneS
G. xu 1 , d. wAnG 1 , M. BuChMeiSer 1
1 Stuttgart University, Institute of Polymer Chemistry, Stuttgart,
Germany
Over the last decade, polyolefin-based materials have
experienced outstanding growth - not only because of the ease of
their manufacture, but also because polyolefin-based
thermoplastics can be recycled or combusted with good
preservation of energy. Furthermore, since they are solely
composed of carbon and hydrogen, the only combustion products
are merely carbon dioxide and water1 . Unfortunately, polyolefins
are highly non-polar, which strongly limits their compatibility
with other polymers as well as dying and coating applications.
Over the last decades, with the development of controlled radical
polymerizations techniques, atom transfer radical polymerization
(ATRP) has been introduced. ATRP offers access to the synthesis
of macromolecules with controlled molecular weights and narrow
molecular weight distributions. ATRP is also characterized by a
great tolerance for the copolymerization of various functional
monomers. Meanwhile, brush- as well as graft-copolymers have
been prepared via ‘grafting to’ and ‘grafting from methods, the
‘grafting from’ method certainly being the best approach in terms
of brush density.
What all ATRP-based methods have in common is the use
of activated alkyl halides, e.g., of a-bromocarboxylic esters. Such
activated halogen-alkyl bonds are weaker than standard alkyl
halide bonds and thus more susceptible to homolytic cleavage by
the Cu (I) complex. Vice versa, to the best of our knowledge, there
are no reports on the ATRP involving non-activated alkyl halides.
Starting from poly-halogenated polyethylene, such an approach
would offer a highly useful access to functionalized polyolefins.
Starting from Poly-brominated linear PE, we successfully
developed an ATRP-based synthesis of a series of novel
well-defined functional poly(ethylene) graft copolymers with
different graft densities and graft lengths thereby developing a
straight-forward access to functional polyolefins2 .
references:
1. Walter Kaminsky, J. Chem. Soc., Dalton Trans., 1998,
1413.
2. G. Xu, D. Wang, M. R. Buchmeiser, Macromol. Rapid
Commun. 2012, 33, 75-79.
Keywords: Poly(ethylene); Atom transfer radical
polymerization; comb-copolymer;
4 th EucheMs chemistry congress
P - 0 4 8 6
Study of AntifunGAL And
AntiBiotiC druGS LoAded MiCroSPhereS
BASed on PoLy(dL-LACtide) And
PoLy(dL-LACtide-Co-CAProLACtone)
P. yAMMine 1 , r. KASSAB 1 , d. MouSSA 1
1 University of Balamand, Chemistry, Tripoli, Lebanon
In an effort to develop a new way of Drug Delivery Systems,
two biodegradable polymers, poly(DL-lactide) (PLA) and
poly(DL-lactide-co-caprolactone) (PLC) were used for the
formulation of microspheres loaded with antifungal drugs
(Nystatin and Amphotericin B) and antibiotics (Tetracycline and
Doxycycline) respectively.
Microspheres were prepared using the solvent evaporation
technique by changing the masses of drugs introduced. They were
then evaluated for percentage yield, drug entrapment, particle size,
morphology, drug-polymer interaction, stability and in vitro
drugrelease.
The particle size analyzer showed a homogeneous size
distribution for the microspheres, ranging between 80 to 110 μm.
The maximum drug entrapment reached 20% and 81% for
PLC microspheres loaded with Nystatin and Amphotericin B
respectively. As for Tetracycline and Doxycycline, the drug
entrapment was 30% and 18% respectively. Scanning Electron
Microscopy (SEM) and Optical Microscopy revealed that the
microspheres have a spherical shape with a porous surface.
Fourier Transform-Infrared (FT-IR) study confirmed the absence
of chemical interaction between the drug and the polymer.
Stability study indicated no appreciable difference concerning the
degradation of the microspheres after 3 months of storage at
different temperatures. The in vitrorelease study was carried out
for the formulations with the highest percentage of encapsulation.
For Nystatin and Amphotericin B, the drug release needed few
days in comparison with Tetracycline and Doxycycline, which
required only several hours to go to completion.
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc