synopsisAn infrared spectrophotometer was calibrated for the quantitative determination of butene-1 in copolymers with propene, and of butenel and limited concentrations of octene-1 in terpolymers with propene. W-tagged standards were used for the butenel calibration wMe standards for the octene-1 calibration were prepared from a homopolymer by blending. Films were pressed from the standards, and the absorbance per mil thicknew was correlated with composition. For our instrument, w t % C, = 510 (A/mil) a t 766 cm-l, and w e % Cs = 539 (A/mil) a t 725 cm-'. No special steps were required to eliininate the effects of crystallinity.