Structural properties of HPMC/PEG/CS thermosensitive porous hydrogels

Thermosensitive hydrogels have widely applications attributed to their special characteristics such as stimuli-responsivity. However, conventional hydrogels are limited owing to the slow response rate. In this study, a thermosensitive porous hydrogel with fast phase transition were successfully synthesized by adding Na2CO3/CH3COOH solution in the hydroxypropyl methylcellulose (HPMC)/polyethylene glycol (PEG)/chitosan (CS) mixture. The structural characteristics of the HPC porous system were investigated by FT-IR and SEM. The Na2CO3/CH3COOH mixture content was optimized by thermosensitivity and water retention experiments. Furthermore, N-2 adsorption-desorption isotherms, rotary rheometer, and DSC experiments were carried out to analyze the parameters of porous, rheological properties, and heat-absorption ability. Results showed that the addition of Na2CO3/CH3COOH mixture effectively improved the porosity parameters of system. When the Na2CO3/CH3COOH mixture content was 0.375 wt%/0.3 wt%, the HPC porous system formed a uniform and interpenetrating framework. The phase transition took just 28 s, and the water retention increased by 58%. The porous diameter was primarily between 80 and 500 A, and pore volume (V-T) increased by 0.0348 cm(3) g(-1). The porous structure could retain a large amount of crystalline water, which increased the absorption enthalpy of the system by 241.383 J g(-1). [GRAPHICS] .

Automated summary

A thermosensitive porous hydrogel with fast phase transition was successfully synthesized by adding Na2CO3/CH3COOH solution. The porous hydrogel exhibited good porosity, rheological properties, and heat-absorption ability.