• biodegradable;
  • pH responsive;
  • phase diagrams;
  • stimuli-sensitive polymers;
  • temperature responsive


Thumbnail image of graphical abstract

A series of novel pH- and temperature-responsive diblock copolymers composed of poly(N-isopropylacrylamide) (PNIPAM) and poly[(L-glutamic acid)-co-(γ-benzyl L-glutamate)] [P(GA-co-BLG)] were prepared. The influence of hydrophobic benzyl groups on the phase transition of the copolymers was studied for the first time. With increasing BLG content in P(GA-co-BLG) block, the thermal phase transition of the diblock copolymer became sharper at a designated pH and the critical curve of phase diagram of the diblock copolymer shifted to a higher pH region. Notably, when the BLG content in P(GA-co-BLG) block was more than 30 mol.-%, the diblock copolymer responded sharply to a narrow pH change in the region of pH 7.4–5.5.