Synthesis and dilute solution properties of branched poly(benzyl methacrylate) using na‐clay supported aqueous‐phase catalysis Part A Polymer chemistry

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 (Mw/Mₙ ≤ 1.33). The hexa‐functionality of synthesized stars is verified by ¹H NMR, the measurement of their intrinsic viscosity ([η]), and radius of gyration (Rg). 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 Mw/Mₙ 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 Mw/Mₙ 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