fluorine-containing finishing agent is the only finishing agent that can not only impart water repellent to the fabric but also oil repellent. From Table 2-1, it can be seen that the surface tension of some aliphatic hydrocarbons oils is about 30×10-3N/m, and when the H in the aliphatic hydrocarbons is replaced by fluorine atoms, its critical surface tension increases exponentially.
from Table 2-1 It can be seen that when the solid surface structure is stacked with -CF3, the lowest surface tension can be achieved, which is far lower than the surface tension of ordinary oils. Therefore, perfluoroalkyl groups should be used as oil-repellent groups, thereby forming a new surface with low surface energy on the fabric, so that the oil cannot be wet. This is the reason why organic fluorine is used in the field of water-repellent oil-repellent in textiles.
To sum up, fluorine-containing finishing agents can only be waterproof and oil-resistant, while fluorine-free finishing agents can only be waterproof.
