PTFE—See Poly

PTDL, see polytridecanolactone PTFE, see polytetrafluoroethylene PTMA, see poly (trimethylene adipate) PTMS, see poly(trimethylaie succinate)... 

Biomedical Applications. Dillon (114) synthesized IPN membranes from polytetrafluoroethylene (PTFE) and poly(dimethyl siloxane) (PDMS) (see Perfluorinated Polymers, Polytetrafluoroethylene Silicones). These flexible membranes are used for a variety of medical purposes, especially second-degree bum care. These materials are commercially available under the trade name Silon. The PDMS component rapidly transports body fluids away from the bum site, while the PTFE provides mechanical strength. The PTFE is also waterproof, so that when the woimd area is washed, water beads up on the film. An additional valuable feature is that the Aims are highly transparent, so that the doctor can observe the wound area easily, making early treatment of any infection or other problem possible. 

For the case of polymers which present reversible solid-solid transitions, producing more disordered forms, with increasing the temperature, (e.g. PTFE, ETFE, 1,4-fran.r-poly butadiene (see Sects. 2.5 and 3.2)) the introduction in the chains of comonomeric units, as well as of other constitutional defects, tends to stabilize the more disordered structure with respect to the more ordered one, and hence to lower the transition temperatures. 

As for enviromnental resistance, there exists a design chart that is somewhat useful for this case study, but, more importantly, may be of use in other designs. The compatibility of various materials in six common environments is shown in Figure 8.16. The suitability of a material for each of the six environments improves as you move from the center of the chart outward. In this case, resistance to organic solvents is of primary importance. We see that all ceramics and glasses, all alloys, and some polymers such as poly(tetrafluoroethylene), PTFE, will provide excellent resistance. Composites will provide good resistance, which may be satisfactory for our application. 

Examples of fluoroplastics include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), ethylene—chlorotrifluoroethylene (ECTFE), ethylene—tetrafluoroethylene (ETFE), poly(vinylidene fluoride) (PVDF), etc (see Fluorine compounds, organic). These polymers have outstanding electrical properties, such as low power loss and dielectric constant, coupled with very good flame resistance and low smoke emission during fire. Therefore, in spite of their relatively high price, they are used extensively in telecommunication wires, especially for production of plenum cables. Plenum areas provide a convenient, economical way to run electrical wires and cables and to interconnect them throughout nonresidential buildings (14). Development of special flame-retardant low smoke compounds, some based on PVC, have provided lower cost competition to the fluoroplastics for indoors application such as plenum cable, Riser Cables, etc. 

See table A4.2. Abbreviations etc. as in table A4.1 PTFE = poly(tetrafluor-ethylene) or Teflon. 

The generic process for electrochemical synthesis of sp-carbon chains was electrochemical reductive carbonization (corrosion) of poly(tetrafluoro-ethylene) (PTFE) by alkali metal amalgams, pioneered by Jansta and dousek [6 9] (for review see Reference 3). The reaction occurs at the interface of a dry contact between PTFE and alkali metal amalgams, hence, it does not seem to recall an electrochemical synthesis in its classical sense. The purely electrochemical carbonization of PTFE on a Pt electrode in aprotic electrolyte solution is also possible [3], but the amalgam-driven process is superior, presenting a clean and well-defined alternative to classical (wet) electrochemistry. 

The acid-base Nafion composite membranes include blends of Nafion with polypyrrole (PPy) [98-104], polybenzimidazole (PBI) [105-107], poly (propyleneoxide) (PPO) [108, 109], polyfurfuryl alcohol (PFA) [110], poly(vinyl alcohol) (PVA) [111-115], sulfonated phenol-formaldehyde (sPF) [116], polyvinylidene fluoride (PVdF) [117-122], poly(p-phenylene vinylene) (PPV) [123], poly(vinyl pyrrolidone) (PVP) [124] polyanifine (PANI) [125-128], polyethylene (PE) [129], poly(ethylene-terephtalate) [130], sulfated p-cyclodextrin (sCD) [131], sulfonated poly(ether ether ketone) (sPEEK) [132-135], sulfonated poly(aryl ether ketone) (sPAEK) [136], poly(arylene ether sulfone) (PAES) [137], poly(vinylimidazole) (PVl) [138], poly(vinyl pyridine) (PVPy) [139], poly (tetrafluoroethylene) (PTFE) [140-142], poly(fluorinated ethylene-propylene) [143], sulfonated polyhedral oligomeric silsesquioxane (sPOSS) [144], poly (3,4-ethylenedioxythiophene) (PEDT) [145, 146], polyrotaxanes (PR) [147], purple membrane [148], sulfonated polystyrene (PSSA) [149, 150], polystyrene-b-poly(ethylene-ran-butylene)-bpolystyrene (SEES) [151], poly(2-acrylamido-2-methyl-l-propanesulphonic acid-co-l,6-hexanediol propoxylate diacrylate-co-ethyl methacrylate) (AMPS) [152], and chitosan [31]. A binary PVA/chitosan [153] and a ternary Nafion composite with PVA, polyimide (PI) and 8-trimethoxy silylpropyl glycerin ether-1,3,6-pyrenetrisulfonic acid (TSPS) has also been reported [154]. 

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