LAUSR

Abstract The thermoresponsive gelation behavior and the degradation behavior of the nanocomposites consisting of poly(ethylene glycol)-b-poly(lactic acid-co-glycolic acid) (PEG-b-PLGA) diblock copolymers and clay nanoparticles (laponite) (laponite/PEG-b-PLGA nanocomposites) were studied by changing the blend ratio of the PEG-b-PLGA diblock copolymers using different PLGA molecular weights of 800 g/mol and 1600 g/mol: PEG-b-PLGA (1000-800, Diblock0.8k) and PEG-b-PLGA (1000-1600, Diblock1.6k). It was found that each gelation temperature was in the temperature range between 25°C and 37°C, when the PEG-b-PLGA concentration and the laponite concentration were kept at 3–4 wt% and 1 wt%, respectively. The degradation rate at 37°C was found to be effectively regulated by the Diblock1.6k/Diblock0.8k blend ratio (DR). In detail, after 15 days of the degradation experiments, the weight loss was decreased by ∼14% when DR changed from DR=0/100 to DR=100/0. It was, therefore, confirmed that DR was the key parameter to control the degradation behavior of the laponite/blended PEG-b-PLGA nanocomposites.