[Determination of hydroxy terminated polybutadiene in the blends by liquid critical condition chromatography]

A method based on liquid critical condition chromatography (LCCC) was established for the quantification of hydroxy-terminated polybutadiene (HTPB) in polymer blends. The critical conditions for HTPB were investigated using a C18 column as the stationary phase, and tetrahydrofuran (THF)-acetonitrile (ACN) or THF-water as the mobile phase. Irrespective of the relative molecular mass, HTPB was eluted under the critical conditions of THF-ACN (70.7:29.3, v/v) or THF-water (92:8, v/v). Under the optimal conditions, the HTPB exhibited satisfactory linearity in the range of 46.7-216.4 mg/L, with a correlation coefficient (r) of 0.997. The limit of detection reached 4.2 mg/L. The recoveries of HTPB from the prepared mixtures of HTPB and mineral oil ranged from 89.2% to 101.1%, with a relative standard derivation of less than 0.66% (n=6). This method was successfully applied to the quantitative analysis of HTPB in a commercial polyurethane adhesive, and 26.6% of HTPB was detected in the product. This LCCC method is simple, convenient, highly selective, and reliable for quality control and failure studies of formulated products.