Polyvinyl chloride (PVC) was milled with hydrated or unhydrated calcium sulfates (CaSO4•2H2O or CaSO4) in air by using a planetary mill to investigate mechanochemical dechlorination behavior. The milling process resulted in size reduction and in the breaking of bonds leading to mechanically induced solid state reaction, forming CaCl2 and dechlorinated hydrocarbon with C=C double bonds in the product. Washing the milled mixtures with water at room temperature allowed removal of the chloride formed during milling, and more than 95% of the chlorine in PVC was removed from a mixture milled for 4 h. This process could offer a potential route for the handling and disposal of both PVC and gypsum wastes. H2S gas was generated during milling; more H2S was released from the unhydrated sample than from the hydrated sample.
- Calcium sulfates
- Mechanochemical dechlorination
- Polyvinyl chloride
- Waste gypsum
ASJC Scopus subject areas
- Waste Management and Disposal
- Mechanics of Materials