不同酚羟基数目羟基苯甲酸的复合对壳聚糖膜性能的影响

Effect of Hydroxybenzoic Acid with Varying Numbers of Phenolic Hydroxyl Groups on Chitosan Film Properties

摘要:

该研究以天然高分子材料壳聚糖为基体，分别添加水杨酸（Salicylic Acid，SA）、原儿茶酸（Protocatechuic Acid，PA）、龙胆酸（Gentisic Acid，GTA）、没食子酸（Gallic Acid，GA）四种不同酚羟基数目的羟基苯甲酸，采用溶剂浇铸法制备成膜。考察了不同酚羟基数目的羟基苯甲酸与壳聚糖共混后复合膜液的流变学特性，使用热重分析（TG）、红外光谱（FT-IR）以及扫描电镜（SEM）对复合膜的结构性能进行表征，并测定了复合膜的机械性能、阻隔性能、总酚释放量和抗氧化性能。结果表明，羟基苯甲酸中酚羟基数目越多，与壳聚糖之间的交互作用越强，使共混膜液中产生高度紧密的网络结构，有利于形成均匀稳定的复合膜。同时具有三个酚羟基的没食子酸与壳聚糖共混成膜后，其紫外阻隔能力良好、水蒸气透过率为1.5010-9 g/(m•h•Pa)、拉伸强度为23.22 MPa、DPPH自由基清除率为71.85%，综合性能表现最佳。以上研究表明，羟基苯甲酸-壳聚糖复合膜的性能受羟基苯甲酸酚羟基数目的影响，酚羟基数目越多，复合膜的综合性能越好。

Abstract:

Chitosan, a natural macromolecular material, was used as the matrix, and each of four types of hydroxybenzoic acid with different numbers of phenolic hydroxyl groups, that is, salicylic acid (SA), protocatechuic acid (PA), gentisic acid (GTA), and gallic acid (GA), were added to prepare composite films using the solvent casting method. The rheological properties of the composite film solutions were investigated. The structure and properties of the composite films were characterized using thermogravimetry (TG), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The mechanical properties, barrier properties, total phenol release, and oxidation resistance of the composite films were also measured. The results showed a strong interaction between chitosan and hydroxybenzoic acid containing more phenolic hydroxyl groups, leading to a more compact network structure, and thus forming uniform and stable composite films. The composite film based on gallic acid with three phenol hydroxyl groups, which had the best comprehensive performance, exhibited good ultraviolet barrier function, vapor transmission rate of 1.5010-9 g/(m•h•Pa), tensile strength of 23.22 MPa, and DPPH radical scavenging rate of 71.85%. This study showed that the performance of hydroxybenzoic acid and chitosan composite films was influenced by the number of phenolic hydroxyl groups; the higher the number, the better the overall performance of the composite film.