氧化微晶纤维素交联壳聚糖复合膜的制备及性能

目的 制备氧化微晶纤维素交联壳聚糖复合膜，并探索交联改性对壳聚糖复合薄膜性能的影响。方法 首先采用高碘酸钠氧化法对微晶纤维素进行氧化处理，制备氧化微晶纤维素，再通过溶液共混流延法制备不同质量分数(0%、1%、3%、5%、7%、9%)的氧化微晶纤维素交联壳聚糖复合薄膜。通过对复合薄膜组分、形貌、力学性能、光学性能、热稳定性及阻隔性能的表征，考察不同含量的氧化微晶纤维素对壳聚糖薄膜各性能的影响。结果 氧化微晶纤维素表面的醛基能与壳聚糖中的氨基发生交联反应，氧化微晶纤维素的加入可以改善壳聚糖薄膜的拉伸强度和断裂伸长率，复合薄膜的拉伸强度和断裂伸长率最大分别达到了43.07 MPa和19.42%;随着氧化微晶纤维素含量的增大，复合薄膜的紫外屏蔽性能增强，水蒸气透过系数增高，但热稳定性未见明显变化。结论 采用氧化微晶纤维素交联改性壳聚糖可以有效改善壳聚糖薄膜的力学性能和紫外屏蔽性能，有助于进一步扩大其包装应用范围。

Preparation and Properties of Oxidized Microcrystalline Cellulose Cross-linked Chitosan Composite Films

The work aims to prepare oxidized microcrystalline cellulose (OMCC) cross-linked chitosan composite films and explore the effects of cross-linking on the properties of chitosan composite films. Microcrystalline cellulose (MCC) was oxidized with sodium periodate to prepare OMCC. Then, composite films with different concentrations of OMCC (0%, 1%, 3%, 5%, 7% and 9%) were successfully fabricated through solution casting method. By characterizing the composition, morphology, mechanical properties, optical properties, thermal stability and barrier properties of the composite films, the effect of different OMCC concentrations on the properties of composite films was investigated. The aldehyde groups on the surface of OMCC were cross-linked with the amino groups of chitosan. The addition of OMCC increased the tensile strength and elongation at break of chitosan films, which reached up to 43.07 MPa and 19.42% respectively. With the increase of the OMCC, the UV-blocking properties and water vapor permeability of the films were improved, while the thermal stability was almost unaffected. The OMCC cross-linked chitosan can enhance the mechanical properties and UV-blocking properties of chitosan film, which is beneficial to broadening its application in packaging field.