Low-flow-resistance Methacrylate-based Polymer Monolithic Column Prepared by Low-conversion Ultraviolet Photopolymerization at Low Temperature

A low-conversion poly(butyl methacrylate-co-ethylene dimethacrylate)-based polymer monolithic column was prepared by ultraviolet (UV) irradiation for a short time at a low temperature (–15°C). By UV irradiation for 2 min, the monolithic column exhibited a high permeability of 5.6 × 10−13 m2 and a high column efficiency of over 100000 plates m−1. At this polymerization time, the conversions of butyl methacrylate and ethylene dimethacrylate were only 10 and 21%, respectively, as determined by pyrolysis gas chromatography. The low conversion led to high porosity, which in turn resulted in high permeability. The reduction in conversion also contributed to improve the compositional homogeneity of the prepared polymer monolith, which would promote high column efficiency. Using the prepared low-conversion column in conjunction with a vacuum-driven low-pressure HPLC without a conventional high-pressure pump, the separation of alkylbenzenes was successfully achieved using a low pressure of only −0.045 MPa to generate the mobile phase stream.