Synthesis and characterization of interpenetrating polymer networks of nanocomposite materials with polyethylacrylate and polystyrene

Interpenetrating polymer networks (IPNs) and pseudo-IPNs (PIPNs) of polyethylacrylate (PEA) and polystyrene (PS) of nanoporous materials were synthesized. Zeolite 13X microporous hybrid inorganic/organic nanocomposites were prepared by radical polymerization of ethylacrylate (EA) and styrene in presence or absence of crosslinker ethylene glycol dimethacrylate (EGDMA). Three mesoporous silicas with different chemical structures (crystalline and amorphous) were used to produce inorganic/organic nanocomposite materials under similar conditions. Both IPN and PIPN of nanocomposites were extracted. All extracted and nonextracted materials were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared spectroscopy (IR), atomic force microscopy (AFM), small angle x-ray scattering (SAXS) and x-ray diffraction (XRD). The result showed there are geometrical constraining effects on polymer chains when the radius of gyration of polymers are larger than pores of inorganic media. The polymer chains could be grown within the internal pores of the inorganic materials. Mechanical measurements of PIPNs and blend samples of polystyrene filled-zeolite 13X and vycor were carried out to determine the physical strength of these materials. Measurements showed higher tensile strength for PIPN films filled zeolite 13X compared to pure polystyrene and blend samples. The membrane catalysts of zeolite 13X incorporated with metal oxides of titanium and nickel were prepared for catalyzing the dehydrogenation of cyclohexane to benzene. The kinetics were studied with proton nuclear magnetic resonance (NMR), and the structures were examined with SEM and IR. Using a pseudo first order reaction approximation led us to obtain the rate constant and activation energy for PIPNs and blend membranes of polyethylacrylate filled with zeolite containing the catalysts. The higher conversion ratio of the blend membranes were consisted with the fact that more exposed catalyst sites are present in zeolite-catalyst (ZC) blend membranes than in ZC PIPN membranes.