Síntese e caracterização de copolímeros à base de poli(metacrilato de metila) e divinilbenzeno com propriedades magnéticas / Synthesis and characterization of copolymers based on methyl methacrylate, divinylbenzene with magnetic properties

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

14/07/2010

RESUMO

In this dissertation, copolymers based on methyl methacrylate (MMA) and divinylbenzene (DVB) with magnetic properties were synthesized by suspension polymerization. It was employed iron as magnetic material. The influence of reaction variables for the microspheress formation as order of addition of the organic and aqueous phases, dispersion of iron before and after pre-polymerization, iron concentration added to the polymerization, MMA/DVB molar ratio, type of suspending agent and stirring speed were studied. The copolymers were characterized with respect to morphology, thermal stability, the amount of iron incorporated, particle size distribution, magnetic properties, surface area and volume and size of pores. The materials obtained showed no hysteresis loops, standing near a material which superparamagnetic with saturation magnetization between 8.0 and 13.0 emu / g. The copolymers with agitation speed 500 RPM, temperature of 90 C, curing time of 24 hours, molar ratio MMA / DVB = 50/50 (mol%); volume ratio organic phase/aqueous phase = 1/3, heptane and 100% degree of dilution showed better morphologic control, better saturation magnetization, smaller particle size and larger pores

ASSUNTO(S)

polímeros propriedades magnéticas polimerização quimica polymers magnetic properties polymerization

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