Polymerization PTFE micropowders

Table 7.7. Another method of producing PTFE micropowders is by controlled polymerization of TFE to a lower molecular weight [105]. Fluoroadditives are used as additives for plastics, elastomers, coatings, printing inks, paints, lacquers and lubricants, where they provide nonstick and/or sliding properties [106]. Benehts provided by PTFE micropowders are summarized in Table 7.8 [107].

Polylite Profile, Mold-making resin, Reichhold Polylube, PTFE micropowder. Custom Compounding, A Div. of Dyneon LLC Polyman, ABS alloys, Schulman, A., Inc. Polymeric Series Foams, Synthetic rubber substitute, Gaska-Tape Inc. 

Polymer chemistry and architecture are key to the properties for which PTFE micropowders are used and the production process dictates much of the architecture. The PTFE micropowders are produced by three general processes (1) direct polymerization of low MW PTFE [28-32], (2) irradiation and grinding of high MW PTFE [33-35], and (3) thermal degradation of high MW PTFE [36,37]. 

The largest proportion of TEE is used for the polymerization into a variety of PTFE homopolymers, modihed PTFE, and micropowders. It is also used as comonomer in the copolymerization with hexafluoropropylene, ethylene, perfluorinated ether, and other monomers and also as a comonomer in a variety of terpolymers. Other uses of TEE are to prepare low-molecular-weight polyfluorocarbons and carbonyl fluoride oils as well as to form PTFE in situ on metal surfaces [14] and in the synthesis of hexafluoropropylene, perfluorinated ethers, and other oligomers [15]. 

As noted above, surface area is an important property for many micropowder applications. The only directly polymerized low MW PTFE available commercially is based on dispersion polymerization (high surface area) so either irradiated granular or thermally degraded PTFE is employed when a low surface area is preferred for the application. 

Method of synthesis granular resin, water dispersions, and powdered resins are produced by free radical polymerization in aqueous medium TFE polymerizes linearly without branching micropowders are produced by irradiation of PTFE by high energy electron beam or polymerization controlled to produce lower molecular weight Diobny, J G, Fluoroplastics, Rapra, 2006. 

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