Vinyl alcohol structural parameters

Cheng et al. [116] reported that the structure of primaquine phosphate irradiated with 0.7—10 Mrad remained unchanged. The energy transfer action of the quinolyl group was considerable due to its resonance stabilization. Radiation-induced degradation of polyl(vinyl alcohol) decreased in the presence of primaquine phosphate but the degradation mechanism was unaffected. The content of primaquine phosphate showed linear relationship with degradation parameters of poly(vinyl alcohol). 

It has been shown recently (10) that such block structures could be tailored precisely by the general method summarized hereabove. It is indeed possible to convert the hydroxyl end-group of a vinyl polymer PA (f.i. polystyrene, or polybutadiene obtained by anionic polymerization terminated with ethylene oxide),into an aluminum alcoholate structure since it is well known that CL polymerizes in a perfectly "living" manner by ring-opening insertion into the Al-0 bond (11), the following reaction sequence provides a direct access to the desired copolymers, with an accurate control of the molecular parameters of the two blocks ... 

Trieu H, Qutubuddin S (1995) Poly (vinyl alcohol) hydrogels 2. Effects of processing parameters on structure and properties. Polymer 36 2531-2539... 

In the field of membrane dialysis the results of an evaluation study for the artificial kidney-chronic uremia programme have been reported (15 contributors). Comparative clinical studies are concerned principally with the relative merits of celiulosic and polyacrylonitrile-based membranes. New membranes based on poly(vinyl alcohol) modified in various ways and on ethylene-vinyl acetate copolymers have been described. The manufacture, and influence of manufacturing parameters, on the structure and function of membranes for artifical kidneys have been discussed. The use of assymmetric hollow fibre haemodialysers (polyamide, polyurethane, polyester) has been considered in some detail. ... 

Corti A., CineUi R, D Antone S., Kenawy E.-R., Solaro R. Biodegradation of poly(vinyl alcohol) in soil environment influence of natural organic fiUers and structural parameters, Macromol. Chem. Phys. 203 (2002) 1526. 

Typically, the temperature dependence of o is not large, but it may be either positive or negative. For example, 10 d In Rl Q/dTis —1.1 for polyethylene, 0.4 for atactic polystyrene, —0.1 to —0.3 for polyisobutylene, —0.2 for poly(ethyl acrylate), 2.2 for poly(hexyl methacrylate) and 0.5 for poly(vinyl alcohol). A large compendium of chain dimension parameters is available in the Polymer Handbook . A 1969 monograph by Flory gives a comprehensive summary of the application of the rotational isomeric state concept with near neighbor interactions to a great variety of real-chain model structures. 

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