Effects of graft density on the separation performance of temperature-responsive materials under the same graft chain length

In present study, three kinds of temperature-responsive chromatography materials with different graft densities under the same graft chain length were synthesized via Atom transfer radical polymerization (ATRP), and they were characterized by Infrared detection and Thermo gravimetric analysis (TGA). Furthermore, the influences of temperature and graft density on the separation performance of steroidal compounds were investigated. The results showed that the graft ratio was higher with higher graft density under the same graft chain length. It is also found that when graft density was too high, it was not suitable for chromatographic materials, and when the graft density was too low, the separation performance was not obvious with the change of temperature. Therefore, choosing a suitable graft density was important for the separation performance of temperature-responsive stationary phase under the same graft chain length.