Synthesis and dilute solution properties of branched poly(benzyl methacrylate) using na-clay supported aqueous-phase catalysis

The supported aqueous-phase catalysis (SAPC) using hydrated interface has been used to synthesize branched polymers (star and graft) of benzyl methacrylate (BnMA) via atom-transfer radical polymerization (ATRP) in the presence of Na-clay supported catalyst in anisole at ambient temperature. The propagation of star poly(BnMA)s using diPENDTA-Br₆, as hexa-functional initiator is confined at the hydrated interface between the support and the liquid medium as evident from the obtained polymers that are catalyst contamination-free, and exhibited moderately narrow molecular weight distributions (M_w/M_n ≤ 1.33). The hexa-functionality of synthesized stars is verified by ¹H NMR, the measurement of their intrinsic viscosity (η]), and radius of gyration (R_g). The polymerization was also recycled up to 5 times to produce star PBnMAs with high initiator efficiency. The star polymers prepared using hydrated Na-clay supported is compared with star prepared using covalent silica supported catalyst system. The star polymer obtained from covalently supported catalyst gave broad M_w/M_n and poor initiator efficiency. The polystyrene-graft-PBnMA (PS-g-PBnMA) copolymer is also prepared using hydrated Na-clay supported catalyst system in anisole at ambient temperature. The graft-copolymer had narrow M_w/M_n and was confirmed using ¹H NMR and atomic force microscopy. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2225–2237