Polymers are more resistant to chemicals than their metal counterparts.
Polymer parts do not require post-treatment finishing efforts, unlike metal.
Polymer and composite materials are up to ten times lighter than typical metals.
Polymer materials handle far better than metals in chemically harsh environments. This increases the lifespan of the aircraft and avoids costly repairs brought about by corroding metal components
Polymers are naturally radar absorbent as well as thermally and electrically insulating.
In medical Facilities polymer and composite materials are easier to clean and sterilize than metal.
Polymer materials allow the oil and gas industry to explore deeper depths than ever before by offering tool weight reduction without a loss of strength as well as materials which offer superior sealing.
Cannot withstand very high temperature as all plastics melt down very soon as compared to metals.
The strength to size ratio of polymer is less while for metals is more.
Cannot be machined easily and limited speed for machining for it.
Heat capacity of polymer is very less so cannot be used in heat applications.
Heavy structure cannot be made by polymer as the structural rigidity is very less.
The disposal becomes an issue as some polymer cannot be recycled but all metals can be recycled.