Hardware components wastes pyrolysis: energy recovery and liquid fraction valorisation

Pyrolysis of hardware components wastes consisting mainly in computers and television components was performed under nitrogen. The degradation products were separated in three fractions, solid, liquid and gaseous. Analyses of the three phases were carried out using gas chromatography (GC), mass spectrometry (MS), thermal analysis and infrared spectroscopy. The energetic content of the gas phase and the economic value of the liquid phase were also determined. The gas fraction produced was rich in light hydrocarbons and hydrogen. Consequently, its calorific value was high and widely sufficient to make the pyrolysis process self-sustained. The main products of the liquid phase were phenol and isopropylphenol (ca. 50–80 wt.%). The presence of Br-based compounds, deriving from the flame retardant employed in hardware components, were also detected. A controlled combustion of the solid phase permitted to obtain the glass fibres unaltered, which can be recycled.     

The behaviour of stereoisomeric ions in the gas phase: 2—Negative and positive chemical ionization of cyclohexanehexacarboxylic methyl esters

The positive ion chemical ionization (CI (isobutane)), negative ion chemical ionization (NICI) electron attachment (CH₄, He) and NICI (OH^?) spectra of the title compounds have been studied in detail with the aid of deuterium-labelled derivatives. The obtained results show that under CI conditions the stereospecificity is retained. Interesting correlations with the condensed phase epimerization yields are emphasized.     

Rapid access to 3-(N-substituted)-aminoquinolin-2(1H)-ones using palladium-catalyzed C-N bond coupling reaction

A series of 3-(N-substituted)-aminoquinolin-2(1H)-ones have been synthesized by the palladium-catalyzed C-N coupling reaction starting from 3-bromoquinolin-2-(1H)-ones. Various nucleophiles including amines, amides, sulfonamides, carbamates and ureas have been used successfully. In all the cases, the reactions take place rapidly in 1,4-dioxane and proceed in good to excellent yield using palladium acetate as a catalyst, Xantphos as a ligand and Cs₂CO₃ as a base.     

Evidence of formation of radicals in the polystyrene thermodegradation

The formation of radicals in the thermal degradation of polystyrene (PS) in tubes sealed under vacuum has been evidenced by using ESR spectroscopy. The radicals were found to be stable for weeks at room temperature. The rate coefficients of the formation of radicals have been evaluated in the temperature range 350–420°C. The reaction kinetically followed has been related to the initiation step of the multi-step degradation process of PS. The activation energy of this reaction resulted 185 kJ/mol.     

Poly(ester urethane) guides for peripheral nerve regeneration

A biocompatible and elastomeric PU was synthesized from low-molecular-weight PCL as macrodiol, CMD as chain extender and HDI as chain linker for applications in the field of peripheral nerve repair. PU cast films supported in vitro attachment and proliferation of NOBEC. The in vitro adhesion and proliferation of S5Y5 neuroblastoma cells on the inner surface of uncoated, gelatin- and PL-coated PU guides were compared. Due to their superior in vitro performance, PL-coated PU guides were tested in vivo for the repair of 1.8 cm-long defects in rat sciatic nerves. The progressive regeneration was confirmed by EMG and histological analysis showing the presence of regenerating fibers in the distal stumps.     

A general copper powder-catalyzed Ullmann-type reaction of 3-halo-4(1H)-quinolones with various nitrogen-containing nucleophiles

3-(N-Substituted) 4(1H)-quinolinones were synthesized using the copper-catalyzed Ullmann C-N bond forming strategy in moderate to quantitative yields. Starting from 3-halo-4(1H)-quinolones, various nucleophiles including amides, lactams, sulfonamides and NH-containing azoles have been used successfully. In all cases, the reactions take place rapidly in toluene and proceed by using copper powder as a catalyst, DMEDA as a ligand and K(2)CO(3) as a base. In addition, other related heterocycles such as 3-bromoquinolin-2(1H)-ones, 3-bromocoumarin, and 3,5-dibromo-2-pyridone show good to very high reactivity with various nucleophiles under our Cu/DMEDA catalyst system.     

Mass spectrometric studies on cyclo- and poly-phosphazenes: 4—Attempts at mass spectrometrically induced polymerization of cyclotriphosphazenes substituted with primary and secondary amines

In this paper, the mass spectrometric behaviour of cyclophosphazenes substituted with primary and secondary amines is investigated, together with the mass spectrometric polymerization pattern of these compounds. While it is not possible to achieve the mass spectrometric polymerization of hexa(anilino)cyclotriphosphazene, ion–molecule reactions take place in the case of hexa(piperidino)- and hexa(morpholino)cyclotriphosphazenes, which lead to the formation of hexameric species. Evidence is given that pentasubstituted cyclophosphazenephosphorus cations are the species responsible for the oligomerization process.