On the basis of structure polymers are classified as-
(i) Linear polymer: These polymers consist of long and straight chain. Examples includes high density polyethylene (HDPE), poly(vinyl chloride) (PVC), etc.
(ii) Branched chain polymers: These polymers contain linear chain having some branches. Examples includes low density polyethylene (LDPE), glycogen, etc. (iii) Cross linked or Network polymers: These polymers have some crosslinks between various linear chains. Examples are Bakelite, melamine, etc