Etude par spectroscopie infrarouge d'alcanes ramifiés et de polymères modèles — application à la determination du taux de ramifications dans les polyéthylènes basse densité

The absorption band at 1378 cm^?1 was used for the quantitative determination of branching in polyethylene. Using various models with different alkyl groups (12-alkyltriacosanes, 11,20-dialkyltriacontances, alkylcyclohexanes, homopolymers), new absorption coefficients, depending on their branching, were obtained. The degrees of branching of a series of copolymers deriving from α-olefins (15 compounds) determined by infrared spectroscopy with the new coefficients and by ¹³C NMR spectroscopy were compared.