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Synthesis and Study of Thermoresponsive Amphiphilic Copolymers via RAFT Polymerization.

ABSTRACT: Synthesis and study of well-defined thermoresponsive amphiphilic copolymers with various compositions were reported. Kinetics of the reversible addition-fragmentation chain transfer (RAFT) (co)polymerization of styrene (St) and oligo(ethylene glycol) methyl ether methacrylate (PEO₅MEMA) was studied by size exclusion chromatography (SEC) and ¹H NMR spectroscopy, which allows calculating not only (co)polymerization parameters but also gives valuable information on RAFT (co)polymerization kinetics, process control, and chain propagation. Molecular weight M_n and dispersity Đ of the copolymers were determined by SEC with triple detection. The detailed investigation of styrene and PEO₅MEMA (co)polymerization showed that both monomers prefer cross-polymerization due to their low reactivity ratios (r₁ < 1, r₂ < 1); therefore, the distribution of monomeric units across the copolymer chain of p(St-co-PEO₅MEMA) with various compositions is almost ideally statistical or azeotropic. The thermoresponsive properties of p(St-co-PEO₅MEMA) copolymers in aqueous solutions as a function of different hydrophilic/hydrophobic substituent ratios were evaluated by measuring the changes in hydrodynamic parameters under applied temperature using the dynamic light scattering method (DLS).

SUBMITTER: Kavaliauskaite M

PROVIDER: S-EPMC8777995 | biostudies-literature |

REPOSITORIES: biostudies-literature

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