Influence of physical characteristics and mechanical properties on polyvinylchloride flexible sheet with calcium carbonate from shells

摘要

Cockles are one of phylum mollusca, when consuming cockles, the shells have to be removed before consuming, causing lots of wastes. This study aims to produce high purity of calcium carbonate (CaCO₃)from cockle shells and investigate the effect of CaCO3 from the cockle shell in polyvinylchloride (PVC) flexible sheet focusing on its physical properties. The experiment was performed by bringing barks of shells; cleaning them in boiling water, then going through the desiccation process at 900°C in order to remove all organic substances and crushing them thoroughly. The resultants became a calcium oxide powder. Calcium oxide was dissolved with distilled water then reacted with sodium carbonate, which resulted in CaCO₃powder. After that, filler in PVC flexible sheet at 5, 10, 15 and 20 part per hundred resin (phr) was compared with commercial CaCO₃. The results showed that cockle shells were successfully in producing CaCO₃which can be used as calcium source with elemental analysis X-Ray fluorescence spectrometer (XRF) and the result showed CaCO₃content 97.68% and median particle size (D50) 10.3 μm. That CaCO₃from the cockle shell indicated mechanical properties as tensile strength and elongation thermal heating shrinkage after aging and slightly increased hardness similar to commercial grade.