Obtenção e caracterização de materiais hibridos organo-inorganicos a base de silsesquioxanos em ponte

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

In this work, organic-inorganic hybrid materiaIs were prepared through an organic component and an alkoxysilane properly functionalized, by the sol-gel process, at room temperature. Dibutyltin dilaurate was used as catalyst of the silane s hydrolyze/condensation reactions. These materiaIs were obtained from the stechiometric mixture of epoxy resin poly(bisphenoI-A-co-epichlorohydrin), PBFE, with g-aminopropyltrimethoxysilane or aminoethylaminopropyltrimetoxysilane, that resulted in the hybrids HSP1 and HSP2, respectively. The addition of 10% in weight of poly(dimethylsiloxane), PDMS, to the reaction mixture mentioned above, has given origin to the hybrids HPP1 and HPP2. In another reaction, the aromatic amine 4,4 -diaminodiphenylmethane reacted with glicidoxypropyltrimethoxysilane to originate the hybrid HSP3. The addition of 10% in weight of PDMS produced the hybrid HPP3. The molecular structure of the hybrids were studied by infra-red spectroscopy. The thermal behavior of the hybrids were evaluated by thermogravimetric analysis and differential scanning calorimetric, presenting good thermal stability and a great number of relaxation. These relaxation can be associated with regions with different cross linked degrees.The morphological analysis of the hybrids fracture surface were done by scanning electron microscopy, SEM, which has given evidences of absence of pores and phase separation. The topography of the hybrids were analyzed by atomic force microscope, AFM. Through this technique, were observed the phase separation in HPP3, that was attributed to the domains richer in PDMS. The nanomorphology of the hybrids were also studied by small angle X-ray scattering, SAXS, that presented, in all cases, scattering profile characteristic of systems with polidisperse scattering centers. The hybrids derived from P1 and P3 could be characterized as volume fractals. All the hybrids obtained have shown good adhesion to a great number of substrates that associated with their physical and chemical characteristics justified the protection effect observed when their were used as coating material for metallic substrates.

ASSUNTO(S)

resinas epoxi compostos organossilicio

ACESSO AO ARTIGO

Documentos Relacionados