Synthesis of star polymers using ultrasound-induced RAFT polymerization

An alternative method to efficiently synthesize Core-Crosslinked Star polymers (arm-first approach) is described in this work. The star polymers are produced utilizing a two-step, one-pot Sono-RAFT process. N,N′-dimethylacrylamide (DMA) is used to prepare the arms, whereas N,N′-methylenebis(acrylamide) (MAA) is employed as the crosslinking agent. The reactions were conducted in an aqueous medium at room temperature. Using the sono-RAFT approach, polymerization under different applied powers, crosslinker to arm ratios, and degrees of polymerization were investigated to determine the optimal reaction conditions for synthesizing star polymers. By altering the applied power, the reaction time can be decreased by half. Using a triblock arm, a CCS polymer was produced, and the resulting polymer demonstrated a very high arm-to-star conversion.