Novel liquid crystalline polymers comprised of polyacetylenes having a comb-like structure were studied by size exclusion chromatography (SEC) with refractive index, right angle laser light scattering, and differential viscometry detectors (RI/RALLS/DV). This combination of SEC detectors is known as triple detector SEC, or simply SEC3. Based upon the data generated for these materials, the relationship between molecular size and the polymer structure was investigated, SEC universal calibration was shown to be valid, Flory's characteristic ratio (C-infinity) was estimated, and the effect of the size of the side group on chain flexibility was elucidated. These results demonstrate that the technique of SEC3 is a powerful mean for characterizing polymers that cannot be effectively characterized by conventional SEC, such as the liquid crystalline polymers of this study.