Pseudo-interpenetrating Networks Research Articles

Low-temperature cis to trans isomerization reaction-separation membranes using zeolite 13X polyethylacrylate

Zeolite–cobalt catalyst filled polyethylacrylate (PEA) reaction-separation membranes converted cis-piperylene to trans-piperylene in yields of more than 20% after 40 h. Pseudo-interpenetrating network (PIPN) membranes were tested by a single cell reactor at low temperatures (313–317 K). Proton nuclear magnetic resonance (NMR) was used to analyze the composition of the throughput and the feed in our experiment. The trans product did not contaminate the feed even after 40 h. Scanning electron microscopy (SEM) results used to analyze the membrane after a 40 h use indicated no cracks on the scale found previously in blend membrane. We also found the pseudo-first-order rate constant and its activation energy for the isomerization reaction in the membrane by using a phenomenological diffusion-reaction model. The latter values are consistent with surface diffusion control of the kinetics.

Low-temperature dehydrogenation reaction–separation membranes using zeolite 13X polyethylacrylate

We prepared blend and pseudo-interpenetrating network (PIPN) membranes containing zeolite 13X with the dehydrogenation catalyst (Ti or Ni) and polyethylacrylate (PEA). Membranes were tested by a single cell reactor using the dehydrogenation reaction of cyclohexane to benzene at low temperatures (323–360 K). Proton nuclear magnetic resonance (NMR) was used to analyze the composition of the throughput and the feed in our experiments. Using 2 wt% of Ti or Ni on 40 wt% of zeolite with 60 wt% PEA the conversion ratio of benzene to cyclohexane was about 4–8%. The feed did not contain measurable amounts of benzene, hence the separation was complete. Scanning electron microscopy (SEM) results showed that the blend membrane developed cracks considerably earlier than the PIPN membrane. We also find the pseudo-first-order rate constant and its activation energy for the dehydrogenation reaction in the membrane by using a phenomenological diffusion–reaction model. The latter values are consistent with surface diffusion control of the kinetics.