Poliimidas porosas para aplicaciones medioambientales

espanolEn el grupo de Policondensacion y Membranas Polimericas del ICTP se han preparado dos series de poliimidas porosas (PPIs) para utilizarse en dos aplicaciones de interes medioambiental: como cargas en membranas de separacion de gases o como soportes de metales convirtiendose en catalizadores heterogeneizados. Para la sintesis de las dos series se utilizaron aminas con diferente geometria (una triamina de geometria trigonal (C3v) y una tetraamina de geometria tetraedrica (Th)) y dianhidridos de diferente longitud, con el fin de investigar la influencia de la estructura molecular de estos monomeros en la porosidad observable. En general los polimeros obtenidos usando la triamina presentaron mayores valores de superficie especifica que los obtenidos con la tetraamina. Por otra parte, no se encontro un efecto claro de la longitud del dianhidrido en los valores de superficie especifica. Las poliimidas mostraron principalmente microporosidad, con excepcion de la poliimida obtenida con la triamina y el dianhidrido mas grande, que presento mesoporosidad. Las PPIs utilizadas como cargas en membranas de matriz mixta (MMMs) para separacion de gases, mostraron un efecto positivo para esta aplicacion ya que aumentaron considerablemente los coeficientes de permeabilidad de la matriz empleada (Matrimid), sin disminuir la selectividad. Dos poliimidas, una de cada serie, se funcionalizaron con grupos amino (PPIs-NH2) para ser empleadas como soportes de Pd, obteniendo los catalizadores heterogeneizados correspondientes, que fueron ensayados en la reaccion de acoplamiento de Suzuki en agua como medio de reaccion. Ambas resultaron ser muy eficaces en esta reaccion a la vez que reciclables. EnglishTwo series of porous polyimides (PPIs) were prepared at ICTP Polycondensation and polymeric membranes’s group to be used in two applications of environmental interest: as fillers in gas separation membranes or as metal supports for heterogenized catalysis. For the synthesis of the two series, two different amines were used, a triamine with trigonal geometry (C3V) and a tetraamine with tetrahedral geometry (Th), and dianhydrides of different length, in order to investigate the influence of the molecular structure of these monomers in the observable porosity. Generally the polymers obtained using the triamine showed higher specific surface areas than those obtained with the tetraamine. However, a clear effect was not found between the length of the dianhydride and the specific surface areas. Polyimides showed mainly microporosity, with the exception of the polyimide obtained with the triamine and the largest dianhydride, which presented mesoporosity. The PPIs used as fillers in mixed matrix membranes (MMMs) for gas separation showed a positive effect for this application because they significantly increased permeability coefficients of the matrix used (Matrimid) without diminishing the selectivity. Two polyimides, one from each series were functionalized with amino groups (PPIs-NH2) to be employed as palladium supports, obtaining the corresponding heterogenized catalysts, which were tested in the coupling reaction of Suzuki in water as reaction medium. Both compounds proved to be very effective in this reaction as well as recyclable.