Polybutadiènes hydroxytéléchéliques, 5. Addition des thiols sur les double liaisons des polybutadiènes hydroxytéléchéliques radicalaire et anionique. Etude des mécanismes d'addition par ¹H et ¹³C NMR

Abstract

Abstract The products of radical addition of butanethiol ( 2 ), 2,2‐dimethylpropanethiol ( 3 ), and 4‐methylthiophenol ( 4 ) to commercial hydroxytelechelic polybutadienes Arco R45M® and Nisso G 2000® were examined by 1 H and 13 C NMR spectroscopy. The rates of addition were calculated by 1 H NMR and the molecular weights were measured by vapour pressure osmometry. The double bonds were found to react completely with 2 , whereas 3 does not react easily. Thiol 4 mainly isomerizes ( cis ‐1,4 into trans ‐1,4). The butylthio radicals were found to be able to add to both carbon atoms of the 1,4 double bonds, whatever the addition modes of the adjacent 1,4 units might be. As far as the 1,2 double bonds are concerned the butylthio radical adds mainly to the terminal methylene carbons.