Microesferas magnéticas à base de poli(metacrilato de metila-co-divinilbenzeno) obtidas por polimerização em suspensão

Abstract

ResumoMicroesferas poliméricas à base de metacrilato de metila (MMA), divinilbenzeno (DVB) e material magnético foram preparadas via polimerização por suspensão. Foi estudada a influência da polimerização em suspensão ou semisuspensão, concentração de material magnético e concentração de divinilbenzeno sobre as características das microesferas obtidas. As partículas poliméricas foram caracterizadas por espectroscopia vibracional na região do infravermelho por transformada de Fourier (FT-IR), microscopia eletrônica de varredura, analisador de área específica e porosimetria, espalhamento de luz e magnetometria de amostra vibrante. O material magnético também foi caracterizado por FT-IR, além de difratometria de raios X e espectroscopia Mössbauer. Foram obtidas, com sucesso, microesferas poliméricas magnéticas à base de MMA e DVB (P(MMA-co-DVB)-M), contendo partículas magnéticas tanto na superfície quanto no interior da microesfera. As partículas obtidas através de polimerização em semisuspensão apresentaram tamanhos menores e distribuição de tamanhos de partículas mais estreita que as partículas obtidas através de suspensões convencionais. Os compósitos apresentaram um comportamento superparamagnético. As microesferas magnéticas sintetizadas neste trabalho têm potencial para serem modificadas e aplicadas como resinas de troca iônica ou suportes catalíticos. Palavras-chave: polimerização em suspensão, propriedades magnéticas, metacrilato de metila, divinilbenzeno, material magnético. AbstractMagnetic polymeric microspheres based on methyl methacrylate (MMA), divinylbenzene (DVB) and magnetic materials were prepared via suspension polymerization. We studied the influence of the suspension or semi-suspension polymerization, magnetic materials and divinylbenzene concentration on the characteristics of the microspheres. Polymeric particles were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy, accelerated surface area and porosimetry analyzer (ASAP), dynamic light scattering (DLS) and vibrating sample magnetometer (VSM). The magnetic materials were also characterized by FT-IR, X-ray diffraction and Mössbauer spectroscopy. Magnetic polymeric microspheres based on MMA and DVB (P(MMA-co-DVB)-M), containing magnetic particles on the surface or inside the microspheres, were successfully obtained. The polymer particles obtained through semi-suspension polymerization had smaller sizes and narrower particle size distribution than particles obtained by conventional suspension. The composites showed a superparamagnetic behavior. The magnetic microspheres synthesized in this work have potential to be modified and applied as ion-exchange resins or catalyst supports.

Core-shell magnetic particles obtained by seeded suspension polymerization of acrylic monomers

“…Poly(vinyl alcohol) (PVA 224) (Kuraray, Tokyo, Japan), sodium chloride (NaCl) (Vetec, Rio de Janeiro, Brazil), sodium dodecyl sulfate (SDS) (B'Herzog, Rio de Janeiro, Brazil), n-heptane (Vetec, Rio de Janeiro, Brazil) and toluene (Vetec, Rio de Janeiro, Brazil) were also used as received. The magnetic material was composed of magnetite, maghemite and goethite, as described in our previous paper [13] .…”

“…The poly(methyl methacrylate-co-divinylbenzene)magnetic core (P(MMA-co-DVB)-M) was synthesized as described in our previous paper [13] . The organic phase (OP) was composed of 0.3 total mols (0.27 mols of MMA and 0.03 mols of DVB), 5% m.m.…”

Comprehensive Review of Magnetic Polymeric Nanocomposites with Superparamagnetic Iron Oxide Nanoparticles for Oil Removal from Water

“…The data were obtained from the Science Direct database However, the main advantage of using magnetic nanocomposites over others is the fact that the material can be collected and separated through the induction of a magnetic field. These properties depend directly on the size distribution of the magnetic nanoparticles and the presence or not of interactions between the surface of the polymeric matrix and the contaminants [46][47][48]. In general, three main types of magnetic nanocomposites are described in the literature: core-shell inorganic nanocomposites [26]; self-assembled nanocomposites [27]; and organic-inorganic nanocomposites [28].…”

Factorial design to obtain magnetized poly(ethyl acrylate-co-divinylbenzene)

“…Finally, the magnetic force was measured with an apparatus developed by the research group of the LaBioS/IMA-UFRJ, using a method to determine the magnetic force in function of the magnetic field generated in the sample. This system is composed of an electromagnet; a Teflon sample holder with volume of 1.76 cm 3 ; a Shimadzu AY22 analytical balance; an ICEL PS4100 power source; a TLMP-HALL-02 Gaussmeter; and an ICEL MD-6450 ammeter [2] .…”

“…These structures can be produced by various polymerization techniques. Suspension polymerization is the most common to generate magnetic spheres, due to the facility of separating the product from the reaction medium, the low level of impurities and the consistency of the spherical particles produced [2,3] .…”