ABSTRACT
The 13C spectrum of polystyrene (PS) homopolymer includes backbone resonances closely spaced between 40 and 45 ppm and aromatic resonances between 125 and 145 ppm. Highly syndiotactic PS (sPS), produced by metallocene catalysts [4,5], has a simple spectrum because of its high stereoregularity. With 1 H decoupling, single peaks appear for each distinct carbon. By contrast, atactic PS (aPS), the more commonly found form of PS, exhibits a complex pattern of resonances for the backbone methine carbon, owing to the irregular stereostructure of this material. Some splitting is also seen for the backbone methylene and the ipso-aromatic carbons, but these effects are more subtle. The assignment of specific peaks to particular stereoisomers has been studied in detail [6,7].
