Synthesis and characterization of temperature-responsive copolymer of PELGA modified poly(N-isopropylacrylamide)

Novel amphiphilic PELGA modified temperature-responsive copolymer, [(poly(methoxyethylene glycol)-co-poly(lactic acid)-co-poly-(glycolic acid))acrylate-co-poly(N-isopropylacrylamide)-co-poly(N-hydroxymethylacrylamide)] (PELGAA-co-PNIPAAm-co-PNHMAAm) was synthesized by incorporating PELGA as the amphiphilic moiety into poly(N-isopropylamide) with various LA/GA ratios. Polymers obtained were characterized by FT-IR, GPC, ¹H-NMR and DSC. The lower critical solution temperature (LCST) of the copolymeric nanoparticles was 40±0.6 °C, the critical aggregation concentration (CAC) was 18 mg L⁻¹, and reversible change in nanoparticle size related to temperature was fluctuated between 210±10 and 109±26 nm, while change in zeta potential of the nanoparticles was between −36±6 and −26±4 mV. The transmission electron microscopy (TEM) images of nanoparticles were also presented.