Properties of a polymer depend on how monomers are linked together. There are three basic structures for polymers – linear, branched and cross-linked.
Linear polymer is the simplest polymer. It has a long, straight chain with identical linkage. PVC is a liner polymer. Teflon is another linear polymer made from tetrafluoroethylene. Branched chain polymers have a long, straight chain with branches of different lengths originating at random points. These branches are known as side chains and can have different lengths. Low-density polyethene (LDPE) used in plastic bags is a branched chain polymer.
There is another category known as cross-linked polymers. It has a three dimensional network of monomers with long chains of linear or branched polymers.
A cross linked polymer has strong covalent bonding that attracts other polymer chains and creates a more stable material. It is also known as network polymer. Bakelite which is used to make sockets is a network polymer.
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