CHEMISTRY GLOSSARY

stabiliser    →   stabilizator

Stabiliser is a substance that makes a mixture more stable. Antioxidants and antiozonants are examples of stabilisers; stabilisers are added to paints to prevent the components of the mixture from separating over time.

EDTA    →   EDTA

Ethyldiaminetetraacetic acid (C₁₀H₁₆N₂O₈) or shortened EDTA is a hexadentant ligand, and it forms chelates with both transition-metal ions and main-group ions. EDTA is used as a negative ion - EDTA^4-. The diagram shows the structure of the ion with the important atoms picked out. The EDTA ion entirely wraps up a metal ion using all 6 of the positions. The co-ordination number is again 6 because of the 6 co-ordinate bonds being formed by the central metal ion.

EDTA is frequently used in soaps and detergents, because it forms a complexes with calcium and magnesium ions. These ions are in hard water and interfere with the cleaning action of soaps and detergents. EDTA is also used extensively as a stabilizing agent in the food industry and as an anticoagulant for stored blood in blood banks. EDTA is the most common reagent in complexometric titration.

polyvinyl chloride    →   polivinil klorid

Poly(vinyl chloride) or the PVC is hard and resistant homopolymer produced by the polymerization of the gas vinyl chloride [CH₂CHCl]. The pure polymer is hard, brittle and difficult to process, but it becomes flexible when plasticizers are added. After mixing with plasticizers, stabilizers, and pigments, the resin may be fabricated by techniques such as calendering, molding, or extrusion into flexible articles such as raincoats, shower curtains, and packaging films. The resin is not plasticized for use in making rigid products such as water pipe, plumbing fittings, and phonograph records.