The role of calcium crosslinking and glycerol plasticizing on the physical and mechanical properties of superabsorbent Alginate/Quince Seed Gum films

In this paper, highly absorbent films based on alginate and Quince Seed Gum (QSG) were fabricated using ionic crosslinking. FTIR analysis was conducted to show crosslinking and network formation. The tensile test revealed an increase in crosslinking time and CaCl2 concentration reduced elongation and increased tensile strength and Young's modulus, but glycerol augmented elongation without a substantial effect on mechanical strength. According to the swelling test, (0.5% w/v CaCl2-2 min) was the optimum crosslinking condition and led to a maximum swelling degree (about 1700%). Exceptional swelling resulted from the high number of hydrophilic groups on the surface of QSG and repulsion forces between negatively charged biopolymers, leading to a great water absorption capacity. Crosslinking reduced the water solubility of films but did not affect Water vapor transmission (WVT). Because of the hydrophilicity of glycerol, adding higher amounts of glycerol decreased the contact angle, reduced the swelling degree, and increased the solubility and WVT of films. Thermogravimetric analysis (TGA) results exhibited that crosslinking imparted a positive effect on thermal stability, while the addition of glycerol adversely influenced it. The properties of Alginate - QSG films demonstrated that they are suitable candidates for biomedical applications like wound healing and drug delivery.

Automated summary

Highly absorbent films based on alginate and Quince Seed Gum (QSG) were fabricated using ionic crosslinking. Tensile tests showed that crosslinking time and CaCl2 concentration affected the mechanical properties of the films, while glycerol had a limited effect. The swelling test demonstrated that the optimal crosslinking condition resulted in a high swelling degree due to the hydrophilic groups on QSG and repulsion forces between biopolymers. The addition of glycerol affected the contact angle, solubility, and water vapor transmission (WVT) of the films. Thermogravimetric analysis (TGA) revealed that crosslinking improved the thermal stability, but glycerol had a negative effect. These alginate-QSG films are promising for biomedical applications like wound healing and drug delivery.