Since polymeric materials can be formed in thin, highly uniform and non porous films with high dielectric strength, these materials are preferred dielectric materials for capacitors. These capacitors are characterised by high insulation resistance at room temperature.
They are made of:
(a) Polystyrene film capacitor
(b) Poly terafluoroethlylene capacitors (P.T.F.E.)
(c) Polythene terephthalate (milliner) capacitors