... nylon (PA), polyester, phenolic / epoxy and other polymer products; phthalic anhydride, maleic ... caprolactam, asphalt and other organic chemical products; and sodium sulfide, ion-exchange membrane (or ... diaphragm) caustic soda, potassium hydroxide, chromic anhydride, sodium hydrosulfide, calcium chloride dihydrate , sulfur, phosphorus pentasulfide and ...