A convenient method for the quantitative determination of terminal hydroxyl microstruc-tures in ethylene-propylene oligomer has been 'developed and evaluated by FT-IR spectroscopy. n-Amyl alcohol or 3-methyl-1-butyl alcohol and 2-butyl alcohol were used as model compounds to assign primary and secondary hydroxyl groups respectiyely. The 3640 cm-1 was selected as key band for measuring the primary hydroxyl group

and the 3623 cm-1 as key band for measuring the secondary hydroxyl group. By using 10 cm-1 path length cells and subtracting spectra to remove interferences of impurity in solution

it is suggested that a reasonalby accurate esti-mate of terminal primary and secondary hydroxyl group would be given by the equation;a=15.8667×103Cp+0.25674.Since the spectral bands of primary and secondary hydroxyl group overlat

the spectral bands were first resolved. By a program of RUN.CAPR in Nicolet FT-IR 170sx

area of repective band was integrated to determine microstructure of terminal hy-droxyl group.