Solvothermal treatment using glycerol effectively removes chlorine from polyvinyl chloride (PVC). Additive-free PVC was dechlorinated by treatment with glycerol in an autoclave at 200–240 °C. Liquid glycerol was coexistent with a red powder after the reaction at 200 °C. At reaction temperatures of 220 and 240 °C, the liquid glycerol disappeared, and carbonization proceeded to form a black powder. In this reaction, the glycerol was directly converted into glycidol. Epichlorohydrin was also produced from the glycerol via 1,3-dichloro-2-propanol as an intermediate. The PVC was converted into the polyethylene oxide structure, following the generation of the polyene structure by zip-elimination. Finally, the converted PVC was resinified by an epoxidation reaction with the glycidol and epichlorohydrin. Thus, glycerol acted as a useful reaction medium for this reaction system. The analysis of the decomposition ratio and dechlorination yield showed that the PVC was converted into solid products in high yields via chlorine release, and 30% of the glycerol was solidified by resinification at 240 °C. The effects of the additives on dechlorination were investigated using commercially available PVC sheets. Elemental analysis showed that the calorific value of the solid product dechlorinated at 240 °C was found to be higher than that of standard bituminous coal.
The magnetic orientation of L-type zeolite ion-exchanged with various rare-earth elements was observed under a low magnetic field of 0.9 T. The orientation along the applied magnetic field was classified into three types: c-axis orientation for Ce3+, Pr3+, Nd3+, Tb3+, Dy3+ and Ho3+, ab-plane orientation for Er3+, Tm3+ and Yb3+, and random orientation for Eu3+ and Gd3+. The different orientation behavior was considered to originate from the electronic structures of the rare-earth ions introduced into the zeolite structure.
10 September 2024 in Microporous and Mesoporous Materials