DETERMINATION OF THE MICROSTRUCTURE OF POLY(CHLOROPHENYL METHACRYLATES) BY C-13 NMR-SPECTROSCOPY

Poly(chlorophenyl methacrylate)s with varying number and positions of the chloro substituent were prepared and investigated using C-13 NMR spectroscopy. The tactic sequence distribution was determined from the signals of the carbonyl carbon (pentads) and the alpha-methyl carbon atoms (triads). It was found that the polymers are predominantly syndiotactic with an average sequence length of between 3 and 4. The isotactic sequences accounted for a very small fraction of the polymer chain with an average sequence length of between 1,3 and 1,5. As for the signals of the aromatic carbon atoms it could be demonstrated that, depending on the substitution pattern of the aromatic ring, the sensitivity on sequence distribution was more or less pronounced.