Linear or branched structure? Probing molecular architectures of fullerene–styrene copolymers by size exclusion chromatographs with online right-angle laser-light scattering and differential viscometric detectors

The poly(C60-co-styrene)s prepared by radical copolymerizations of C60 and styrene in bulk were characterized by multiple-detector size-exclusion chromatographs consisting of a refractometer, a differential viscometer, and/or a right-angle laser-light scattering photometer. The multidetector systems enabled the determinations of reliable, absolute molecular weights of the copolymers. The plots of intrinsic viscosity vs. molecular weight and radius of gyration vs. molecular weight offered valuable information about the molecular architectures of the copolymers. The slopes of the plots reveal that the structure of the copolymer changes with its C60 content: the copolymer with a low C60 content of 0.58 wt% possesses a linear structure, whereas its conger with a high C60 content of 1.14 wt% possesses a branched structure.