What Is Fluoro Polymers
A Fluoro polymer is an organic compound consisting of fluorine and carbon atoms but can also contain oxygen or hydrogen. The atoms are held together by bonds to form monomers such as tetra fluorethylene (TFE). When the monomer is polymerized they form into long chains to which TFE becomes polytetrafluoroethylene (PTFE). Fluoro polymers can be either fully fluorinated or partially fluorinated.
Introduction
Fluoropolymers are distinguished particularly by their high thermal, chemical and weather resistance, excellent surface properties (especially oil and water repellency) and optical properties (low refractive index). Accordingly, fluoropolymers are indispensable materials in a wide variety of industries
1. FULLY FLUORINATED
- PTFE (POLYTETRAFLUOROETHYLENE)
- PFA (PERFLUOROALKOXY)
- FEP (FLUORINATED ETHYLENE PROPYLENE)
2. PARTIALLY FLUORINATED
- ETFE (ETHYLENE TETRAFLUOROETHYLENE POLYMER)
- ECTFE (ETHYLENE CHLOROTRI FLUORO ETHYLENE POLYMER)
- PVDF ( POLY VINYLIDENE FLUORIDE)
Since fluoropolymers came on the market in 1930s, they have been applied as coating materials in order to achieve those characteristics mentioned above on the surfaces of various substrates. Typical examples include coatings made from aqueous dispersion poly tetra fluoroethylene(PTFE), etrafluoroethylene/hexafluoroethylene copolymers (FEP), and tetra fluoroethylene/perfluoroalkyl vinyl ether copolymers (PFA) for non-stick and anti-corrosion applications. However, those fluoropolymers are not necessarily suitable for use as coating materials due to their poor solubility in conventional organic solvents, the requirement of baking temperatures greater than 200℃ and weak adhesion to substrates.
Among the well-known fluoropolymers, only polyvinylidene fluoride (PVdF) has been used for coatings as an organic dispersion, mainly for architectural applications due to its outstanding weather ability.
A unique solvent soluble fluoroolefinvinyl ether co-polymer (abbreviated as FEVE co-polymer, with the trade name “LUMIFLON”) was developed in 1982 by Asahi Glass. This co-polymer consists of alternating sequences of fluoroolefin and several specific vinyl ether units (Fig.1), and is completely amorphous. This alternating sequence is responsible for extremely high weather resistance of the resultant paint finishes. Combinations of several kinds of vinyl ether co-monomers provide the polymer with other useful physical properties, such as solubility in organic solvents, pigment compatibility , cross-linking sites and impart good adhesion, hardness and flexibility to the coating. The major reason for the use of FEVE co-polymers as raw materials for coatings is their excellent weather resistance. The hydroxyl group in the FEVE polymer functions as the cross-linking site with blocked isocyanates or melamine resins for heat cured coatings, and with aliphatic polyisocyanates for on-site coatings.
