Waste fluoropolymer

Fluoroplastics described in this book are thermoplastics and can be reused under the right circumstances. There are a few sources of waste fluoropolymers. Various processing steps such as preforming, molding, machining, grinding, cutting create debris and scrap. Some... 

PVDF components are used extensively in the high purity semiconductor market (low extractible values), pulp and paper industry (chemically resistant to halogens and acids), nuclear waste processing (radiation and hot acid applications), and the general chemical processing industry (chemical and temperature applications). Fluoropolymers have also met specifications for food and pharmaceutical processing industries. 

The only way to apply chemically bonded thin perfluorosulfonic acid layer onto the surface of an inert support is to graft perfluorinated functional monomers onto perfluorinated polymers. Some features of radiation-induced graft copolymerization of PFAVESF onto fluoropolymers were investigated. The studies showed that neither irradiation of a fluoropolymer-PFAVESF mixture (direct grafting) or interaction of PFAVESF with previously irradiated fluoropolymers (preirradiation grafting) yielded the grafted copolymers. It was assumed that this is connected with the low activity of PFAVE in radical polymerization. A special method has been developed for the synthesis of grafted copolymer. Previously irradiated fluoropolymer powders were used to prevent waste of PFAVESF. 

Recovery/Removal and Recycling of Perfluorinated Acids from Fluoropolymers and Industrial Waste Streams In the last decade of the twentieth century, PFOS and PFOA as well as other fluorinated substances came under scrutiny because they are environmentally persistent and potentially bioaccumulative. Analytical developments resulted in the detection of these substances widespread in the environment [28]. Triggered by these environmental concerns, as well as by the high price of the fluorinated emulsifiers, methods were developed which allowed effective recovery and recycling of fluorinated emulsifiers from these industrial production processes. 

In some cases, used perfluorinated fluoropolymers (e.g., PTFE, PFA) are recycled by special cleaning processes and are ending up in the Repro-PTFE or micropowder-PTFE-market. Perfluorinated thermoplasts (e.g., PFA) are reused in applications where the quality requirements (e.g., lot traceability) are much lower. Overall, the lion s share of used fluoropolymers is, however, ending up in landfills, in incineration plants, or in blast furnaces. Communal waste incinerators can tolerate only very limited amounts of fluoropolymers due to the high corrosion due to hydrofluoric acid formed in the process. 

Organic Filler - Organic fillers are made from natural or synthetic organic materials. Natural material derived organic fillers include wood and shell flours. Synthetic material derived fillers include fluoropolymer spheres and milled polymer waste. Organic fillers are characterized by relatively low cost and low density. They might increase the flammability and decrease the moisture resistance of plastics. See also Mineral Filler. 

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