Example 30
The typical protocol for the preparation of PNMEP28 macro-CTA is described below. NMEP (9.37 g, 47.4 mmol), CPDB RAFT agent (0.30 g, 1.36 mmol; target DP=35), ACVA (76.0 mg, 0.27 mmol; CPDB/ACVA molar ratio=5.0) and ethanol (14.59 g, 40% w/w solids) were weighed into a 50 mL round-bottom flask immersed in an ice bath and degassed with continuous stirring for 30 min. The reaction was allowed to proceed for 270 min in an oil bath set to 70° C., resulting in a monomer conversion of 90% as judged by 1H NMR spectroscopy. The polymerization was then quenched by exposing the hot reaction solution to air and cooling to 20° C. The crude polymer was precipitated into excess diethyl ether to remove residual monomer before freeze-drying in the minimum amount of water to afford a dry pink powder. The mean DP was calculated to be 28 by comparing the integrated aromatic protons arising from the CPDB RAFT agent. GPC analysis using chloroform eluent indicated an Mn of 5000 g mol−1 and Mw/Mn of 1.23 against a series of ten near-monodisperse poly(methyl methacrylate) calibration standards.
