4th EucheMs chemistry congress

tuesday, 28-Aug 2012
s791
chem. Listy 106, s587–s1425 (2012)
organic Chemistry, Polymers – ii
Polymer chemistry – iii
o - 2 3 0
SeLf-heALinG PoLyMer CoAtinGS BASed on
the (retro) dieLS-ALder reACtion
M. d. hAGer 1 , J. KoetteritzSCh 1
1 Friedrich-Schiller-University Jena, Laboratory of Organic and
Macromolecular Chemistry (IOMC), Jena, Germany
Self-healing materials feature the extraordinary property that
a damage inflicted to them can be healed (partially or completely).
Hereby the original function of the material can be restored. In
Nature this process is very common: a cut in the finger can be
healed, broken bones merge,...
However, man-made materials very often lack this special
ability. In contrast to natural materials they were designed in order
to prevent the damage, not to manage and handle damage, which
will inescapable occur during usage of common materials.
Self-healing coatings are of particular interest, because coatings
are very prone to damage. Latter will lead to a loss of the function
of the coating: protection of the underlying material and
aesthetical exterior.
Self-healing can be achieved in coatings by extrinsic
materials, i.e. a healing agent is embedded into the coating
(e.g., within capsules). In addition, the polymeric material of the
coating itself can feature the ability for healing. In this context,
we report the synthesis of novel acrylic polymers, which contain
both binding units for the Diels-Alder reaction (i.e. the maleimide
and the furan moiety). The ATRP was utilized to synthesize
well-defined functional terpolymers, which could be crosslinked
via thermal treatment. Different comonomers have been utilized
to tune the thermal and mechanical properties of the resulting
polymer networks.
Moreover, the healing of scratches in polymer coatings,
based on these materials, was investigated. The influence of the
crosslinking density, the kind of the comonomer and the healing
temperature on the ability for self-healing was investigated in
detail. Efficient healing of polymer coatings could be obtained.
Keywords: Polymers; Materials science; Cycloaddition;
Pericyclic reaction;
Polymer chemistry – iii
4 th EucheMs chemistry congress
o - 2 3 1
deSiGn And SyntheSiS of noveL Serine BASed
GeMini SurfACtAntS: how doeS StruCturAL
ModifiCAtion AffeCt MiCeLLizAtion And
CytotoxiCity
M. L. C. do vALe 1 , S. G. SiLvA 1 , C. M. ALveS 1 ,
A. M. S. CArdoSo 2 , M. C. PedroSo de LiMA 2 ,
A. S. JurAdo 2 , e. f. MArqueS 1
1 Faculty of Sciences of the University of Porto, CIQ
- Centro de Investigacio em Química and Department of
Chemistry and Biochemistry, Porto, Portugal
2 CNC - Centre for Neurosciences and Cell Biology and
Department of Life Sciences, University of Coimbra, Coimbra,
Portugal
Gemini surfactants represent a new generation of
compounds composed of two surfactant monomers linked
chemically at or near the head groups by a rigid or flexible spacer.
Owing to their excellent performance and enhanced
physicochemical and biological properties in comparison to the
corresponding monomeric counterparts, gemini surfactants have
a broad range of applications, ranging from cosmetic and food
formulations, models for membranes and microreactors, to drug
and gene delivery systems, among others. [1] Therefore, considerable
efforts have been made to design and synthesize new forms of
gemini surfactants, focusing on the effect of the nature of the polar
head group and of the spacer length and hydrophobicity on the
aggregation properties as well as on the toxicological profile of
the compounds.
In this context, our research group has been engaged in the
synthesis and evaluation of the basic physicochemical properties
of amino acid based monomeric and dimeric surfactants. [2] In the
present work, the results obtained with two novel series of cationic
gemini surfactants based on serine are presented. The most
efficient synthetic pathway was established and involves the
introduction of the spacer into the N, N-dialkylated monomeric
precursors by peptide condensation methods, subsequent
methylation and deprotection. The final target surfactants have
either an amide or an ester bond between the polar head group
and the spacer. These surfactants showed enhanced micellization
properties compared to the conventional bis-quats. A study
on the influence of the nature of the spacer linkage as well as of
the spacer chain length has been performed. The cytotoxicity
of the compounds has also been evaluated.
Acknowledgement: Thanks are due to FCT
(PTDC/QUI-BIQ/103001/2008; PTDC/QUI/115212/2009;
SFRH/BD/61193/2009; CIQUP);
FEDER (REDE/1517/RMN/2005).
references:
1. F. M. Menger, J. S. Keiper, Angew. Chem. Int. Ed. 2000,
39, 1906–1920; [2] S. Goreti Silva, Ricardo F. Fernandes,
Eduardo F. Marques, M. Luísa C. Vale, Eur. J. Org. Chem.
2012, 345–352.
Keywords: surfactants; synthesis; cytotoxicity; self-assembly;
amino acids;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc