Preparation of temperature-sensitive chromatographic materials via reversible addition fragmentation chain transfer polymerization

This paper prepared temperature-sensitive chromatographic materials via reversible addition fragmentation chain transfer polymerization (RAFT), and FT-IR, XPS, TG and element analysis characterizations indicated temperature-sensitive polymer grafted successfully onto silica. The introduction of S-benzyl dithiobenzoate that acted as chain transfer agent in RAFT formed an active site, which triggered polymerization of N-isopropylacrylamide on the surface of silica. The mole ratio of chain transfer agent and initiator was controlled to regulate the grafting ratio. TG analysis demonstrated the grafting ratio increased with a higher amount of initiator. The increasing grafting ratio improved thermosensitivity of HPLC performance of modified silica and separation of four steroids at 10, 30 and 50 ℃. Experimental results indicated RAFT successfully prepared temperature-sensitive chromatographic materials.