The structure of stereoregular polymers of 1,3‐pentadiene was determined by 13C‐NMR spectroscopy at 22.6 MHz. Not only was it possible to distinguish between cis‐1,4 and trans‐1,4 but also between isotactic and syndiotactic cis‐1,4 structures. Triad effects were detected in the trans‐1,2 syndiotactic polypentadiene; 1,4–1,2 as well as 1,4–4,1 linkages were observed.
Carbon-13 nuclear magnetic resonance configurational assignments are made for a free-radical polystyrene sample examined at 25.033 MHz and 140°C. The spectra of the aromatic C 1 and methylene were examined. New assignments were established based strictly on a oneparameter Bernoullian fit that was in satisfactory agreement with the relative intensities of the peaks observed.
The deposition of films from an argon plasma containing a mixture of ethylene oxide or hydrogen and perfluorohexane was tried to obtain very hydrophobic, less hydrophobic and intermediate coatings. This paper studies more extensively the deposition of a thin coating from a perfluorohexane and hydrogen plasma on polysulfone and polyhydroxybutyrate membranes to optimize their surface properties without affecting their filtering properties. The plasma deposition of smooth and very hydrophobic fluorocarbon coatings seems to increase the bio-and hemocompatibility of poorly biocompatible membranes. The treated substrates were characterized by measuring the mass variations, surface profilometry and contact angle measurements, as well as scanning electron microscopy and electron spectroscopy for chemical analysis.
Cis-polyacetylene films have been synthetized and doped with iodine and antimony penta fluoride, using usual chemical techniques. Doping, leads, after saturation, to conductivity values of about 120 and 25 (Ω cm) -1 at room temperature, respectively for I2 and SbF 5 dopants. The E.S.R. of cis- and trans-, non-doped and doped (CH)x films has been studied. A qualitative analysis of the results allows a better understanding of the electronic properties of these extremely non homogeneous and highly conductive doped polymeric materials
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