6Siggia S, Hanna J G. Use of differential reaction rates to analyze mixtures of organic materials containing the same functional group [J]. Anal Chem, 1961, 33: 896~900.
7Lebas C L, Turkey P A. Primary hydroxyl content in polyol-evaluation of two nuclear magnetic resonance(NMR) methods [J]. Journal of Cellular Plastic, 1984, 194~197.
8Kxueger R P. Gnauk R. Differentiated determination of primary and secondary hydroxyl groups in poly(ether alcohol)s by chemical means [J]. Plastc Kautsch, 1981, 28(11): 618~637.
9Novak P, Ilavsky M, Pavals P, et al. The problem of determination of hydroxyl groups in poly(oxyvthylene) diols by using the phenylisocyanate method [J]. Die Angerw Makromol Chem, 1990, 179: 87~98.
10Crumment W B. Determination of the primary hydroxyl group content of polypropylene glycols [J].Analytical Chemistry, 1964, 34(9): 1147~1150.