Investigation of the dependence of the infrared absorptivity of a functional moiety on the molecular weight of a homopolymer

The subject of this investigation was the determination of the effect of molecular weight (MW) on the infrared absorptivity of a functional moiety in polystyrene homopolymer. It was found that no consistent dependence of infrared absorptivity on MW was found for two sharp absorptions of polystyrene across the MW range from 600 to 2 × 10⁶. It was shown that end group effects for the very-low-molecular-weight polymer fraction may be subtle and should be accounted for when using homopolymer calibration standrads in the study of the dependence of copolymer composition on MW.