Separation of Chlorine in Shell Powder/PVC Composite Materials
Masayoshi KITAGAWA, Peng LI, Fumihiko MAEJIMA and Wataru MIZUNO
Abstract:Poly (vinyl chloride) (PVC) is a general-purposed plastic material widely used in the industry and daily life. It has quite good compatibility with some other plastics and plasticizers. However PVC is known to be fairly unstable at higher temperature. Hydrochloride acid (HCl) gas is generated due to the thermal decomposition during molding process and when it is thrown into fire. This may cause serious problems such as the corrosion of molding machine and the environmental pollution. Shell is a natural material, which contains 99wt% calcium carbonates. Since there are piles of wasted shells on the coastline, utilization of these shells has been expected in those areas. In this study, the role of shell powder mixed in PVC as an entrapping agent of HCl generated at the processing and burning of PVC was investigated. Two kinds of waste shells were ground into powder and mixed in PVC. HCl entrapping efficiency during burning process of PVC/shell powder composites were investigated and the change in the mechanical properties were also measured. The results obtained clearly show the excellent efficiency of shell powder to entrap HCl generated and the efficiency depends on the type and size of the powder. It is concluded that the shell powder in PVC composite materials is effective to separate generated chlorine from PVC and therefore, is benefit to the environment. Key Words:PVC, Scallop shell, Calcium carbonate, Hydrochloric acid, Composite material