6533b852fe1ef96bd12aaa98

RESEARCH PRODUCT

UV-photometrische analyse kationisch erzeugter polystyrole, 1. Nachweis des covalenten einbaus von acylresten aus aromatischen acylperchloraten

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Polymerization of styrene was found not to take place with 4-phenylazobenzoyl perchlorate in benzene solution. 4-Biphenylcarbonyl perchlorate, however, initiates styrene polymerization under the same conditions leading to a product not containing acyl groups as indicated by UV spectroscopic analysis. 4-Phenylazobenzoyl, 2-naphthoyl, and 9,10-dioxo-2-anthracenecarbonyl perchlorate (6b, 7b, and 8b), prepared form silver perchlorate and the corresponding acyl chlorides 6a, 7a, and 8a in styrene, were found to initiate the polymerization of styrene under anhydrous conditions at −25°C in the dark. By UV spectroscopy it could be shown that the resulting polymers contain covalently bound acyl groups. Their absorption bands correspond to those of model compounds 6c, 7c, 8c, and 7d, respectively. IR spectra of mixtures of polystyrene with model compounds show that incorporation of acyl groups can be detected by their carbonyl absorption in the region of 1680 – 1700 Cm−1 only in polystyrenes having molar masses <50 000.