Poly vinylene

It is noteworthy that photoluminescent poly(vinylene-arsine)s have also been prepared by radical copolymerisation of phenylacetylene and an arsenic atomic biradical equivalent [71]. 

We have had smart materials as materials for a long time though the term is relatively new. Some of the first smart materials were piezoelectric materials, such as poly(vinylene fluoride), which emit an electric current when pressure is applied and change volume when a current is passed through it. Most smart materials are polymeric or have a critical portion of the smart system that is polymeric. 

Poly(tetramethylene adipate) 200.23 Poly(vinylene diphenylsilylene) 208.34... 

Considerable evidence exists to support the suggestion that intramolecular peroxides are more important than intermolecular or cross-linked peroxides. In addition to Bailey s work, intramolecular peroxides have been identified during the oxidation of vinyl chloride [180] and of poly-vinylene chloride [181]. In the octene, where such peroxides cannot be formed, hydroperoxides are produced by the more conventional radical reaction involving attack on the a-methylene hydrogen atom... 

Field and Schaefgen (5) demonstrated that a high molecular weight poly (vinylene carbonate) (PVCA) was obtained if the first step of the synthesis, photochlorination of ethylene carbonate, was carried out in CC14 instead of bulk reaction and if the monomer was distilled from NaBH4 shortly before polymerization. On the other hand, bulk chlorination led invariably to poor quality VCA. 

Fig. 3 Infrared spectrum of (A) poly(vinylene carbonate). This spectrum as a thin film was recorded using a ModeI-21 Perkin-Elmer spectrometer. Reprinted from N. D. Field and J. R. Schaefgen, J. Polym. Sci. 58, 533 (1962). Copyright 1962 by the Journal of Polymer Science. Reprinted by permission of the copyright owner.

The thermal elimination process can be applied to most substituted groups in vinyl polymers by controlled pyrolysis at 600 to TOO C, producing poly vinylene compoimds, e.g., by the splitting off of acetic acid from poly(vinyl acetate). By careful temperature control, one can achieve bifunctional reactions and/or intramolecular cyclizations. This has been developed commercially at relatively high temperatures, in the case of the polymerization of methacrylamide above 65°C, to yield a polymer with a substantial proportion of imide groups ... 

We have confirmed by an in-situ subtracfively normalized interfacial FTIR (SNIFTIR) that the polymer by VC begins to form at 4.3 V vs. Li /Li on Li CoO as shown in Fig. 4.12, where the upward peaks at 1,830, 1,805, and 1,750 cm below 4.3 V correspond to the consumption of VC, EC, and EMC, respectively. This resultant polymeric film formed at 4.3 V suppressed the further decomposition of EC and EMC above 4.3 V, where the downward peaks at 1,850-1,800 and 1,650-1,550 cm can be ascribed to the formation of decomposition products. The chemical structure of the polymer was assumed to be a poly(vinylene carbonate) by XPS. However, the reaction between Li jCoO and VC at 85°C did not show the existence of polymeric materials. These results indicate that the thermal stability... 

Incorporated heteroatoms perturb the n resonance system, thus increasing conductivity (violanthrene as opposed to violanthrone). Poly-(carbazene) and poly(azasulfene) also show considerably higher conductivity than poly(vinylene). It can be quite generally assumed that all conducting and semiconducting polymers are conjugated, but not all the (formally) conjugated polymers are semiconductors. 

Fig. 22. Cis levels for poly-vinylene fluoride and polyvinylidene fluoride.

SCHEME 1.3 Tentative chelating of potassium cation by poly vinylene moieties. 

Various approaches have been developed to improve the solubility of NTs in different polymer matrices. The addition of 1 wt% non-ionic surfactants improves, for instance, the glass transition temperature. Moreover, the elastic modulus increased by more than 30% relative to the absence of a surfactant [76]. In the presence of 0.5 wt% poly(vinylene fluoride) (PVDF) the storage modulus of MWNTs/PMMA composites was significantly improved at low temperatures [77]. 

---