There are two basic types: the first is the linear structure, the polymer with this structure is called linear macromolecule, the second is the body structure, the polymer with this structure is called body type macromolecule compound. Some polymers with branched chain, called branched-chain polymers, belong to the linear structure.
Some polymers, although there are cross-linking molecules, but less cross-linking, called the network structure, belongs to the body structure. Two different structures, showing two opposite properties. Linear structure, heating can melt, hardness and brittleness of the characteristics of small. The size structure is hard and brittle. Plastic is a two-structure polymer, made of linear polymers is thermoplastic, made of body-shaped polymers are thermosetting plastic.