Polyphosphates are phosphate polymers linked between hydroxyl groups and hydrogen atoms. The polymerization that takes place is known as a condensation reaction. Phosphate chemical bonds are typically high-energy and are difficult to separate. Adenosine triphosphate (ATP) is an example of a phosphate trimer, a polymer with three phosphate groups.
DNA is built on a type of phosphate/sugar copolymer. Essentially, it consists of alternating deoxyribose and phosphate groups linked together to form a chain or backbone. Nucleotide bases attach to the sugar and form hydrogen bonds with a bases on a complimentary chain. The entire system consists of two long chains which coil up in a helix-like structure. RNA is simular, the two differences being, the sugar ribose being used in the phosphate/sugar backbone rather than deoxyribose and uracil being used instead of thymine as the aromatic base.
Sodium tri-polyphosphate (Na5P3O10) has been used widely as a constituent of laundry detergents, acting as a water softener in hard water regions and improving detergent performance. In recent years, concern has grown that this results in substantial amounts of phosphates entering the sewage system and thence to watercourses, resulting in eutrophication. This has led to the amounts of polyphosphates in detergents being legally controlled in a number of countries (e.g., Germany, Italy, Austria)