Thermal decomposition of acrylamide from polyacrylamide

Ion-attachment mass spectrometry with a temperature-programed direct probe allows the detection of intact pyrolysis products. It, therefore, offers the opportunity to monitor directly thermal byproducts on a real-time basis and potentially to detect thermally unstable products. With this technique, we investigated the thermal decomposition of polyacrylamide (PAA). Pyrolysis of PAA at around 450?°C produces many products (e.g., amides, imides, nitriles, ketones, aldehydes, and acrylamide oligomers). Acrylamide, which is a possible carcinogen, is produced abundantly in various industries, and, therefore, continues to be a cause for concern. We also investigated the kinetics of the thermal decomposition of PAA, and observed that the degradation of acrylamide obeys Arrhenius kinetics, which allowed us to correlate the rate constant with the absolute temperature and the activation energy. The activation energy of thermal decomposition was calculated from selected ion-monitoring curves of acrylamide.     

Ultrasonic separation of a suspension for in situ spectroscopic imaging

Optical Review - Application of spectroscopic techniques to suspensions is difficult because optical scattering caused by solid particles reduces the accuracy. At the extreme, dense suspensions...     

Synthesis of helical shaped 1,1′-bibenzo[c]phenanthrene-2,2′-diol (HEBPOL) derivatives by reduction of helical quinones

A new class of helical shaped bi-phenol (1,1′-bibenzo[c]phenanthrene-2,2′-diol; HEBPOL) type derivatives 2a–g were synthesized from quinone derivatives using the conventional 5% Pd-C catalytic reduction process. We obtained excellent yields for all of the 2a–g derivatives. The HEBPOLs were characterized by different analytical techniques including FTIR, ¹H NMR, ¹³C NMR, MS and X-ray crystallography.