Final answer:
Dacron is a polyester formed through a condensation reaction and step-growth polymerization, known for its use in various products due to its strength and flexibility.
Step-by-step explanation:
The class of polymer that forms the repeating unit for Dacron, a popular synthetic fabric, is known as polyesters. This type of polymerization is characteristically a condensation reaction, often leading to the loss of a small byproduct like water. These polyesters form through step-growth polymerization, involving carbon-heteroatom bond formation (specifically C-O bonds in the case of Dacron). Dacron is also referred to by the brand names Terylene in the UK, Lavsan in Russia, and Dacron in the US, and has applications in clothing, magnetic tapes, and high-tech sails, among others. Polyester fibers like Dacron are known for their strength, flexibility, and durability.