Page 45 - PR 2014 2016 10 Materials and Nanotechnology
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Materials and Nanotechnology | Progress Report 321
Especially butyl rubber, halogenated rubbers The fluoroelastomer has been selected as the
are a little more radiation resistant. Irradiat- matrix polymer because of its properties, such
ed butyl, bromobutyl and chlorobutyl rubber as: solubility; chemical resistant to aliphatic
compounds and sheared at 25 kGy doses pre- and aromatic hydrocarbons; physical resistant
sented compatible results between scission to high temperature; low gas permeability;
and crosslinking and, so, they were selected for and others. The inorganic nanoparticles are
the mixtures between pristine and recovered clay and a silsesquioxane polymer (POSS). The
rubber. The assessment of physical-chemical objectives of the use of these particles are im-
properties of compounds comprising recovered proving the mechanical property, reducing the
rubber showed that the addition of recovered swelling of the elastomer and maintaining
rubber via irradiation and shearing favors a the dimensional stability. The incorporation
slight decreasing in tensile and elongation at was carried out by mixture process in a two
break. Nevertheless, results indicate a com- roll cylinder at room temperature. After the
patibility of this incorporation. In summary, incorporation, the samples were pressed in
it was possible to conclude that, in spite of order to vulcanize and to obtain films with
further adjustments in formulations, contain- 0,2mm thickness. The films will be submitted
ing recovering of butyl and halobutyl rubbers, to gamma radiation to induce graft polymeriza-
the strategy of a previous irradiation and a tion by simultaneous method. After irradiation,
further shearing showed a great potential in the films will be immerse) in the sulfonation
recycling scenery. solution to complete the experimental part.
Development of sulfonates Issues on hydrogels for drug delivery
multifunctionals fluoroelastomers based
on nanocomposites Hydrogels for wound dressings are usu-
ally developed for contact surfaces where
Polymer nanocomposite is a material formed mechanical properties are conveniently re-
by a polymer matrix and, usually, an inorganic quired. In this sense, nanocomposite hydro-
compound. This inorganic material has nano- gels based on poly(vinyl alcohol) (PVAl) and
meters with size of 100nm and is dispersed in poly(N-2-vinil-pirrolidone) (PVP), containing
the matrix. These nanocomposites have been 0.5 - 1.5 wt% of the synthetic laponite RD clay,
studied in Universities and industries because were prepared by gamma radiation process
of the final properties presented by this kind and compared with similar membranes com-
of material. The combination of properties posed separately of PVP or PVAl. This study
of organic and inorganic materials revealed aimed to evaluate the effect of clay on the
an improvement of mechanical, thermal, properties and the differences of the poly-
electrical and optical properties. In the case mer binary system instead of a one polymer
of nanocomposites, the same behavior was nanocomposite hydrogel. The morphology of
noticed due to the incorporation of inorganic the hydrogels was evaluated by spectrometric
nanoparticles in the polymer chain. In this techniques using X-Ray Diffraction, scanning
work, the effect of incorporation of inorganic electron microscopy (SEM), swelling, and In-
nanoparticle in the fluoroelastomer matrix frared Spectroscopy (FTIR). Swelling kinetics at
has been studying. The selection of materials 22 °C and mechanical properties by tensile test
is very important because the mixture process evaluated the structural properties. The results
and quality of final product. showed PVA/PVP network depends directly of
