PTFE-TFM

Fig. 3.7 Milestone MultiPREP-50/80 with PFA vessels (left) and PRO 16/24 with PTFE-TFM pressure vessels (right).

PRO 16/24 rotor (Fig. 3.7) Advanced rotor for high-throughput purposes under elevated temperature and pressure conditions utilizing 16 or 24 reaction containers. The 70 mL PTFE-TFM vessels offer 35 mL working volume at 200 °C up to 20 bar. 

MPR-6 large-volume rotor (Fig. 3.8) Dedicated for parallel scale-up, this rotor comes with six segments for 270 mL PTFE-TFM vessels. Reactions can be performed on a 15-140 mL scale at operation limits of 200 °C up to 10 bar. 

HPR monobloc (Fig. 3.8) For applications at high pressure, the HPR monobloc is available. This tool features six 100 mL PTFE-TFM vessels fixed in a strong casing, serving operation limits of 300 °C and 100 bar. 

High-pressure rotor (Fig. 3.8) Two variations of parallel high-pressure rotors are available. The MPR-12 comes with 12 segmented 100 mL PTFE-TFM vessels for reactions at up to 260 °C and 35 bar. For more forceful conditions in volumes of 8-50 mL, the HPR-10 provides for 10 segmented 100 mL PTFE-TFM vessels for reactions at up to 250 °C at 55 bar. 

For the individual rotor types, different vessels are available. The 16-vessel rotor, dedicated for the performance of standard reactions at up to 240 °C, offers 100 mL PTFE-TFM liners. Applying different pressure jackets allows continuous operation of these vessels to a maximum of 20 or 40 bar, respectively. The 8-vessel rotor is designed for high-pressure reactions, offering PTFE-TFM liners or quartz vessels, which enable reactions to be performed at 300 °C and 80 bar for several hours. 

Liner material PTFE-TFM PTFE-TFM PTFE-TFM quartz... 

Pumps can be used for both loading and unloading nitric acid. Standard chemical pumps may be used for nitric acid concentrations up to 70% if they are made of suitable materials (for example, DIN/EN 1.4408 = UNS I 92900 (ASTM A 296 Grade C78M). Magnetically coupled, side-channel pumps made from Antinite (DIN/EN 1.4361 = UNS S 30601) or compressed-air diaphragm pumps made of PTFE/TFM composite are recommended for highly concentrated nitric acids above 70%97. 

Somewhat between PTFE and PFA materials is the product Hostaflon TFM, which is a copolymer of TFE and a small amount of the perfluoro(propyl vinyl ether). It has improved impact strength and weldability and has been promoted as a suitable material for forming into bottles. Yet another TFE-perfluoroalkoxy copolymer was introduced by Du Pont in 1979 as Teflon EPE. This material had a somewhat lower melting point (295 °C) than the more common PFA fluoropolymers but it is no longer marketed. 

Hostaflon TF 2071 Hostaflon TF 5032 Hostaflon TF 5033 Hostaflon TF 5034 Hostaflon TF 5444 Hostaflon TF 5515 Hostaflon TF 5537 Hostaflon TF 9202 Hostaflon TF 9203 Hostaflon TFM 1600 Hostaflon TFM 1700 Hostaflon TFX 2072 Hydrocer F9174 Klingerflon PTFE (Virgin)... 

PTFE is called a homopolymer, a polymer made from a single monomer. Recently, many PTFE manufacturers have added minute amounts of other monomers to their PTFE polymerizations to produce alternate grades of PTFE designed for specific applications. Fluoropolymer manufacturers continue to call these grades modified homopolymer at below 1% by weight of comonomer. DuPont grades of this type are called Teflon NXT resins. Dyneon TFM modified PTFE incorporates less than 1% of a comonomer perfluoropropyl vinyl eflier (PPVE). Daikin s modified grade is Polyflon M-111. 

Dyneon TFM PTFE improved performance and design flexibility. Dyneon 2003. 

Hostaflon TFM Modified suspension PTFE Hoechst Celanese Corp. 

Hostaflon TFM, The Second Generation PTFE, Dyneon Corp., Gendorf, Germany, 1996. 

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