SYNOPSISThe effect of the monomer/water ratio on the rate of polymerization per polymer particle in both seeded emulsion polymerizations and miniemulsion polymerizations was used in an attempt to elucidate the main locus of radical formation in emulsion polymerization initiated by an oil-soluble initiator ( AIBN) . It was found that, for the rest of conditions constant, the polymerization rate per polymer particle increased when the monomer/water ratio increased, namely when the amount of initiator dissolved in the aqueous phase per polymer particle decreased. This is an evidence against a dominant aqueous phase formation of radicals. On the other hand, these results are consistent with a mechanism in which the radicals are mainly produced in the oil-phase with significant aqueous phase termination.
In this work the growth of polymer brushes was combined with nanoimprint lithography (NIL)
in order to obtain new functional nanopatterns. First, a functional thermoplastic methacrylic
copolymer poly(methyl methacrylate-co-2-bromoisobutyryl-oxy-ethyl methacrylate) was
synthesized. This copolymer was successfully patterned by NIL using a silicon stamp at
160 °C
and 60 bar. Next, hydrophilic polymer brushes based on poly(3-sulfopropylmethacrylate)
and hydrophobic polymer brushes based on a poly(fluorinated methacrylate) were grown on
the imprinted surfaces. The surface properties of the patterned polymer were
accordingly modified and, as a consequence, the water contact angle was modified from
80.3° to
32.5°
in the case of the hydrophilic brushes and to
118.1°
in the case of the hydrophobic brushes. As an application we demonstrated the use of
hydrophobic polymer brushes in order to modify the surface of polymeric stamps for NIL
with self-demoulding properties.
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