TY - JOUR

T1 - Gel-Phase Synthesis and pH-Sensitive Swelling-Structure Relationships of N-Carboxyethylchitosan

AU - Саейди, Арсалан

PY - 2025/6

Y1 - 2025/6

N2 - The applicabilityof native chitosan-based compositions is constrained by their limited solubility in weakly alkaline and neutral media, a consequence of inherent structural features. To overcome this limitation, car-boxyalkylation strategies such as the gel-phase Michael synthesis of N-carboxyethylchitosan (N-CEC) were investigated with a focus on optimizing reaction parameters to enhance yield and tailor biopolymer proper-ties. Structural confirmation of the synthesized polymers was performed via FT-IR and SEM, while elemental analysis quantified the degree of substitution (DS), which correlated with temperature in the following way: DS = 0.96–1.10 at 50°C, 1.07–1.12 at 60°C and 1.16–1.32 at 70°C.Porosity measurements indicated pore sizes ranging from 50 to 200 μm in all samples; however, total porosity varied significantly, reaching a max-imum of 15% at 70°C and decreasing to 4–10% at lower temperatures. N-CEC exhibited pH-dependent swelling, with minimal expansion (100–150%) at low pH and a 2–3-fold increase at pH>7, which was at-tributed to COO⁻group formation. These findings position N-CEC as a promising material for pH-responsive applications.

AB - The applicabilityof native chitosan-based compositions is constrained by their limited solubility in weakly alkaline and neutral media, a consequence of inherent structural features. To overcome this limitation, car-boxyalkylation strategies such as the gel-phase Michael synthesis of N-carboxyethylchitosan (N-CEC) were investigated with a focus on optimizing reaction parameters to enhance yield and tailor biopolymer proper-ties. Structural confirmation of the synthesized polymers was performed via FT-IR and SEM, while elemental analysis quantified the degree of substitution (DS), which correlated with temperature in the following way: DS = 0.96–1.10 at 50°C, 1.07–1.12 at 60°C and 1.16–1.32 at 70°C.Porosity measurements indicated pore sizes ranging from 50 to 200 μm in all samples; however, total porosity varied significantly, reaching a max-imum of 15% at 70°C and decreasing to 4–10% at lower temperatures. N-CEC exhibited pH-dependent swelling, with minimal expansion (100–150%) at low pH and a 2–3-fold increase at pH>7, which was at-tributed to COO⁻group formation. These findings position N-CEC as a promising material for pH-responsive applications.

M3 - Article

JO - Eurasian Journal of Chemistry

JF - Eurasian Journal of Chemistry

SN - 2959-0663

ER -