Polyvinylide fluoride (PVDF) and polytetrafluoroethylene (PTFE) belong to a group of highly chemical resistant fluorothermoplastics.
PTFE has very high crystallinity with the highest density of all polymers. It has high thermal stability and extremely low moisture absorption. Because of its resistance to chemicals PTFE is commonly used in chemical, food and pharmaceutical engineering. PTFE is favoured over PVDF for sliding applications with exposure to extreme chemical stress.