明胶改善海藻酸钠水凝胶膜的物理性能研究

Gelatin Improves the Physical Properties of Sodium Alginate Hydrogel Films

本研究旨在解决Ca^(2+)交联海藻酸钠水凝胶膜极易脱水收缩,三维网络结构单一及热机械性能较差等问题,具体是以海藻酸钠和明胶为成膜基材,以碳酸钙和葡糖酸内酯为交联剂,通过流延法制备水凝胶膜,探究明胶/海藻酸钠的不同比例(0:6、1:6、2:6、3:6、4:6、5:6)对水凝胶膜物理性能的影响。本实验利用傅里叶变换红外光谱对水凝胶膜分子间作用力进行分析,并通过微观结构、溶胀率、凝胶含量、水接触角、机械性能和热性能等指标对水凝胶膜物理性能进行表征。结果表明:明胶和海藻酸钠之间的作用力主要为氢键和聚电解质相互作用,明胶的引入有效改善了单一海藻酸钠水凝胶膜的三维网络结构,提高了水凝胶膜的凝胶含量和疏水性,增强了水凝胶膜的机械性能和热性能,但明胶/海藻酸钠的比例过大也会造成明胶与海藻酸钠相容性和机械性能的下降。综上,当明胶/海藻酸钠的比例为3:6时,水凝胶膜的拉伸强度(29.6 MPa)、弹性模量(164.99 MPa)、凝胶含量(38.91%)和溶胀率(2942.50%)最高,此时水凝胶膜的物理性能最佳,在诸多领域具有潜在的应用价值。

This study aimed to solve the problems of Ca^(2+) crosslinked sodium alginate hydrogel film,such as easy syneresis,single three-dimensional network structure,and poor thermomechanical properties.Specifically,sodium alginate and gelatin were used as filming substrates,calcium carbonate and gluconolactone were used as crosslinking agents to prepare hydrogel films by casting method.To investigate the effects of different ratios of gelatin or sodium alginate(0:6,1:6,2:6,3:6,4:6,5:6)on the hydrogel films physical performance.In this experiment,the intermolecular forces of hydrogel films were analyzed by Fourier transform infrared spectroscopy,and the physical properties of hydrogel films were characterized by microstructure,swelling ratio,gel fraction,water contact angle,mechanical properties and thermal properties.The results showed that the interaction between gelatin and sodium alginate was mainly hydrogen bonding and polyelectrolyte interaction.The introduction of gelatin effectively improved the three-dimensional network structure of the single sodium alginate hydrogel film,increased the gel fraction and hydrophobicity of the hydrogel film,and enhanced the mechanical properties and thermal properties of the hydrogel film.However,the ratio of gelatin/sodium alginate was too high resulting in poor compatibility and mechanical properties of gelatin and sodium alginate.In summary,the tensile strength(29.6 MPa),elastic modulus(164.99 MPa),gel fraction(38.91%)and swelling ratio(2942.50%)of the hydrogel film were optimal when the ratio of gelatin/sodium alginate was 3:6,at which time the physical properties of the hydrogel film were optimal and had potential applications in many fields.