Poly Vinylidene Fluoride PVF

These crystal modifications differ in their molecular and crystal structures as well as in their physical properties. Many types of crystalline modifications are reported, including a stable orthorhombic phase and metastable monoclinic phase for PE a, and y forms for isotactic polypropylene (/-PP) trigonal and orthorhombic phases for polyoxymethylene a and y forms for Nylon 6 and others. Poly(vinylidene fluoride) (PVF), for example, appears in at least four types of crystalline modification (Lovinger, 1985 Dunn Carr, 1989). 

Fig. 11.6 SEM images of submicron poly(vinylidene fluoride) (PVF,) particles on a polished silicon substrate (silicon wafer, left) and a polyester copolymer (right). The (van-der-Waals) attraction force between the particles and the substrates is so great that particles embed into the soft polymeric material (right) but not into the silicon (left), although in the latter case they are flattened at the contact points [B.39, Vol. 2, p. 51]...

Table 14.4. Liquid surface tension, /iv, at which maximum (Max) or minimum (Min) in sedimentation volume occurs, for several polymers PTFE, polytetrafluoroethylene PVDF, poly(vinylidene fluoride) PVF, poly(vinyl fluoride) HOPE high-density polyethylene PA 66, poly(hexamethylene adipamide) (nylon 6, 6) PSF, polysulfonate. Experiments were performed at room temperature, and the extrema are to be understood as being the surface tensions of the polymers (from refs (65, 66)) ... 

Figure 3.1 Evolution of fluoropolymer development over time. PCTFE, Polychlorotrifluoroethylene PVDF, poly-vinylidene fluoride PVF, polyvinyl fluoride FEP, fluorinated ethylene propylene copolymer ECTFE, ethylene-chlorotrifluoroethylene copolymer ETFE, ethylene-tetrafluoroethylene copolymer PFA, perfluoroalkoxy copolymer AF, amorphous fluoropolymer.

Poly(vinylidene fluoride) (PVDF) Ethylene-chlorotrifluoroethylene copolymer Ethylene-tetrafluoroethylene copolymer Poly(vinyl fluoride) (PVF)... 

The fluoropolymer family consists of polymers produced from alkenes in which one or more hydrogens have been replaced by fluorine. The most important members of this family are polytetrafluoroethylene (PTFE) (XLVII), polychlorotrifluoroethylene (PCTFE) (XLVIII), poly(vinyl fluoride) (PVF) (XLIX), poly(vinylidene fluoride) (PVDF) (L) copolymers of... 

PS PSF PSU PTFE PU PUR PVA PVAL PVB PVC PVCA PVDA PVDC PVDF PVF PVOH SAN SB SBC SBR SMA SMC TA TDI TEFE TPA UF ULDPE UP UR VLDPE ZNC Polystyrene Polysulfone (also PSU) Polysulfone (also PSF) Polytetrafluoroethylene Polyurethane Polyurethane Poly(vinyl acetate) Poly(vinyl alcohol) poly(vinyl butyrate) Poly(vinyl chloride) Poly(vinyl chloride-acetate) Poly(vinylidene acetate) Poly(vinylidene chloride) Poly(vinylidene fluoride) Poly(vinyl fluoride) Poly(vinyl alcohol) Styrene-acrylonitrile copolymer Styrene-butadiene copolymer Styrene block copolymer Styrene butadiene rubber Styrene-maleic anhydride (also SMC) Styrene-maleic anhydride (also SMA) Terephthalic acid (also TPA) Toluene diisocyanate Ethylene-tetrafluoroethylene copolymer Terephthalic acid (also TA) Urea formaldehyde Ultralow-density polyethylene Unsaturated polyester resin Urethane Very low-density polyethylene Ziegler-Natta catalyst... 

Fluoro-substituted Polymers. The fluoropolymers were between the first to be studied by the XPS technique because the substitution of F atom(s) in the -CH.-CH - unit induced very large modifications in the XPS core level spectra (shifts up to 8eV) that were easy to detect and interpret. The XPS valence band spectra of similar compounds, namely poly(vinyl fluoride) (PVF), poly(vinylidene fluoride) (PVF2), poly(trifluoroethylene) (PVF3), and poly(tetrafluoroethylene) (PTFE) (26, 27, 28) are also expected to reflect the induction of such strong electronic effects at the valence molecular level. 

Chiu (116) used the apparatus previously described to study the thermal decomposition of selected polymers such as polyethylene terephthalate), po y(vinyl fluoride), po y(vinylidene fluoride), and others. The dielectric constant curves of a group of fluorocarbon polymers are shown in Figure 11.33. As illustrated, the more polar polymers such as poly(vinylidinefiuoride) (PVDF) and poly(vinyl fluoride) (PVF) show characteristic dielectric loss peaks that are distinguishable from the relatively featureless and low-loss curves of the other polymers. For PVF, the low-temperature process is due... 

Figure 11.9 (a) Poly(vinyl fluoride), PVF, [CH2— CHF (i) dipoles present in a tetrahedral unit of PVF and (ii) isotactic structure of a polymer chain of PVF. (b) Poly(vinylidene fluoride), PVF2, [CH2—CF2] (i) dipoles present in a tetrahedral unit of PVF2 and (ii) isotactic structure of a polymer chain of PVF2... 

The melting point data of poly(vinylidene fluoride) in the presence of poly(methyl methacrylate) or poly(ethyl methacrylate) obey the prediction of eq.fb), as shown in Fig. 5. The Bx2 values are -2.98 cal/cmP HyiMA and -2.86 cal/cm3 PEMA. The addition of a methylene group to the side chain of the methyl methacrylate polymer does not seem to have significant influence on its compatibility with PVF at elevated temperatures. 

The commercially important fluorocarbon polymers are poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), poly[tetrafluoroethylene-co-(perfluoroaJkylvinyl ether)] (PFA), and amorphous fluoropolymer (AF), typically copolymers of tetrafluoro-ethylene and fluorinated dioxole. The second group of fluoropolymers includes modified poly(tetrafluoroethylene-co-ethylene) (ETFE), poly(vinylidene fluoride) (PVDF) (sometimes referred to as PVF2), and copolymers of vinylidene fluoride, poly(chlorotrifluoroethylene) (PCTFE), poly(chlorotrifluorethylene-co-ethylene) (E/CTFE) and poly(vinyl fluoride) PVF. 

PTV PU PVA PVAC PVAL PVC PVDC PVDF PVE PVF PXRD py Py PY Py-GC-MS pyr pyrr pz programmed-temperature vaporizer polyurethane poly (vinyl alcohol) poly(vinyl acetate) poly (vinyl alcohol) poly (vinyl chloride) poly(vinylidene dichloride) poly(vinylidene difluoride) poly (vinyl ether) poly(vinyl fluoride) powder X-ray diffraction pyridine (ligand) pyridine pyramidal (coordination compounds) pyrolysis-gas chromatography-mass spectrometry pyrazine (ligand) pyrrolidine (ligand) pyrazole (ligand)... 

Polytetrafluoroethylene (PTFE Teflon) was discovered accidently by PlunkettCZ nd commercialized by DuPont in the 1940 s. This polymer has a solubility parameter of about 6H and a high melting point of 327°C and is not readily moldable. Poly-chlorotrifluoroethylene (CTFE, Kel-F), the copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), polyvinylidene fluoride (PVDF, Kynar), the copolymer of tetrafluoroethylene and ethylene (ETFE), the copolymer of vinylidene fluoride and hexafluoroisobutylene (CM-1), perfluoroalkoxyethylene (PFA) and polyvinyl fluoride (PVF, Tedlar) are all more readily processed than PTFE. However, the lubricity and chemical resistance of these fluoropolymers is less than that of PTFE. 

Adhesion, processibility, and dyeability of PVF have been improved by grafting it with a number of non-fluorocarbon monomers.f Styrene, methyl methacrylate, vinyl acetate, and vinylidene chloride have been grafted to poly(vinyl fluoride) films by using Co y-rays or an electron accelerator. 

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