How are addition polymers formed?
Polyethylene The simplest synthetic polymer is polyethylene, which is made by joining ethylene molecules together. One of the bonds in the C=C is broken, and these electrons instead attach one of the C’s to a C in the next molecule. The result is very long carbon chain. We won’t worry about what’s on the ends; addition polymers are written inside ( ), to show that the molecule keeps going in both directions. Since this is an organic molecule, we can also represent it with condensed structures, or with line structures. condensed structure: line structure: There are two kinds of polyethylene – HDPE (high density polyethylene) and LDPE (low density polyethylene). HDPE is rigid, strong, and heat resistant – special catalysts are used during the polymerization that create regions where the strands line up. It is used to make strong plastic bottles, tables, fences, milk jugs, and many other products. LDPE is flexible and low-melting – it just has a tangled web of polymer strands. It is used
