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• Thermoresponsive amphiphilic star-shaped polymers were synthesized via RAFT. • The optimization studies were performed to achieve the best conditions for uniform starpolymers. • The acquired optimization conditions resulted in high-yield CCSs (>99 %). • Varying temperatures confirmed the thermoresponsive properties of CCS. The well-defined starpolymers can offer a precise stimuli-responsive drug delivery system (SDDS). For this, core cross-linked starpolymers (CCSs) using the poly(N -isopropylacrylamide)- b -poly(n -butyl acrylate) (PNB) linear arm chain and ethylene glycol diacrylate (EGDA) cross-linker were designed and synthesized by the reversible addition-fragmentation chain transfer (RAFT) system. The important synthetic parameters, including reaction time, radical concentration, and cross-linker concentration, were varied to optimize the reaction conditions for highly uniform PNiPAM-based amphiphilic starpolymers (PNBA). The reaction was monitored by GPC, resulting in the sharp monomodal PNBA GPC curve with an almost degraded original curve corresponding to the PNB linear chain. The PNBA revealed a dramatic size increase from 150 nm to 15,000 nm when the temperature increased up to 40 °C. Notably, the uniform CCS structure gives rise to a particular phase transformation system, which can be helpful in biomedical and catalytic applications with enhanced performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porphyrin-cored amphiphilic star block copolymers were well synthesized via ATRP. • Hydrophobic polymer-type and block fraction were varied for hydrophobicity control. • More intensified hydrophobicity led to more efficient photooxidation of furfural. Pd-contained porphyrin-cored (P(Pd)) amphiphilic star block copolymers with a hydrophobic interior, including either poly(methyl methacrylate) (PMMA) or poly(dodecyl methacrylate) (PDMA), and poly(ethylene glycol) methyl ether methacrylate (PEGMA) hydrophilic outer layer were synthesized by Ru-catalyzed atom transfer radical polymerization (ATRP). The acquired starpolymer photocatalysts were examined for photooxidation of furfural. The starpolymers with the PDMA hydrophobic interior led to higher efficiency in the photooxidation of furfural than the starpolymers without hydrophobic interior and with the PMMA interior. In addition, the grater hydrophobic PDMA fraction exhibited a higher photooxidation efficiency. Those experimentally demonstrated the importance of the hydrophobic interior toward efficient photooxidation. We believe that this study provides a fundamental idea in developing amphiphilic star block copolymer photocatalysts. [ABSTRACT FROM AUTHOR]