Synthesis of POEGMA-POPSMA

Typically, POEGMA-CTA (150 mg, 0.055 mmol), OPS₇MA (1 g, 1.3 mmol), AIBN (0.9 mg, 0.0055 mmol), and DMF (5 mL) were charged into a Schlenk flask which was capped with a rubber septum. The flask was degassed with argon by three freeze-pump-thaw cycles. After thermostating at 75 °C in an oil bath and stirring for 31 h, the mixture was precipitated into an excess of diethyl ether for three times. The final product was dried under vacuum overnight at room temperature, yielding a yellowish-brown oily product (0.37 g, 32%). M_n (GPC) = 8.5 kg/mol, M_w/M_n (GPC) = 1.28. The average number of OPS₇MA repeat units was determined to be 8 by ¹H NMR analysis in CDCl₃, thus the polymer was denoted as POEGMA-POPS₇MA_8.