Polychloroprene Degradation by Photo-Fenton. Conductivity Measures as New Approach for Detecting/Evaluation of Degradation Products

In the present work the photo-degradation of polychloroprene (PCP) in toluene solution catalyzed by FeCl₃·6H₂O and polychromatic light was investigated based on FTIR and ¹³C NMR spectroscopies, on conductivity measurements and DSC technique. The band in the 1700–1790 cm⁻¹ range in the FTIR spectrum characterized the presence of carbonyl products due to the degradation of the PCP on the solution exposed to polychromatic light. The formation of carbonyl on degraded PCP was confirmed by the presence of signal on ¹³C NMR at δ 203.5. Products of PCP degradation, such as acid chlorides, generated in the toluene solution migrate to the aqueous phase (in contact with toluene phase) and the conductivity of aqueous phase increased as the time is elapsed. The area related to the PCP melting-peak on the DSC (film casted after the PCP-FeCl₃·6H₂O toluene solution has been exposed to polychromatic light) significantly decreased in comparison to that in the DSC of the raw PCP cast film.     

Synthesis of Reinforced Polyurethane Composites from a Matrix Composed of Recycled PET Oligomers Incorporating Undeveloped Brazilian Pine-Fruit Seeds

Journal of Polymers and the Environment - The main objective of this research was to set the experimental conditions needed for the successful synthesis of a composite (PU-UBPFS) made from...     

Urban atmospheric pollution: personal exposure versus fixed monitoring station measurements

We initiated the PETER (pedestrian environmental traffic pollutant exposure research) project to investigate pedestrians' exposure to traffic related atmospheric pollutants, based on data obtained with the collaboration of selected categories of pedestrian urban workers. We investigated relations between roadside personal exposure levels of volatile aromatic hydrocarbons (including benzene) and particulate matter <10 microm (PM10) among traffic police (n = 126) and parking wardens (n = 50) working in downtown Bologna, Italy. Data were collected from workshifts throughout four 1-week periods in different seasons of 2000-2001. For benzene and PM10, comparisons were made with measurements by fixed monitoring stations, and influence of localized traffic intensity and meteorological parameters was examined. Roadside personal exposure to benzene correlated more strongly with other volatile aromatic hydrocarbons (toluene, xylenes and ethylbenzene) than with PM10. Benzene and PM10 personal exposure levels were higher than fixed monitoring station values (both p<0.0001). At multivariate analysis, benzene and PM10 data from fixed monitoring stations both correlated with meteorological variables, and were also influenced by localized traffic intensity. Plausibly because of the downtown canyon-like streets, weather conditions (during a period of drought) only marginally affected benzene personal exposure, and moderately affected PM10 personal exposure. These findings reinforce the concept that urban atmospheric pollution data from fixed air monitoring stations cannot automatically be taken as indications of roadside exposures.