为了制备性能更优的胶原膜，使其更好地应用于食品包装领域，采用不同氧化度的氧化羟丙基甲基纤维素（DHPMC）与胶原以质量比1:1.25共混成膜，考察DHPMC氧化度对胶原复合膜理化性能的影响。结果表明，胶原复合膜的三股螺旋结构未被破坏，且相比于纯胶原膜，其机械性能、热稳定性、耐酶降解性和亲水性能均有增强，结构更加均匀致密。当DHPMC氧化度较低（氧化度17.78%）时，DHPMC分子中的醛基与胶原的氨基形成共价键，体系的相互作用增强，且DHPMC氧化度低，对复合膜的成膜性能影响小，使得复合膜的抗张强度（115.74 MPa）和热变性温度（76.24 ℃）相较于胶原/羟丙基甲基纤维素（HPMC）复合膜（104.69 MPa，69.67 ℃）提高。当DHPMC氧化度较高（氧化度45.12%）时，DHPMC的醛基含量增加，但同时纤维素降解程度也增加，使得复合膜的抗张强度（93.56 MPa）和热变性温度（71.13 ℃）下降。因此，采用低氧化度的DHPMC与胶原共混可制得综合成膜性能更优的复合膜，将扩大其在食品包装中的应用范围。

In order to prepare a collagen film with improved performance and make it more suitable for food packaging, dialdehyde hydroxypropyl methylcellulose (DHPMC) with different oxidation degrees were blended with collagen at a mass ratio of 1:1.25 to form films. The effects of the oxidation degree of DHPMC on the physico-chemical properties of collagen composite films were investigated. The results indicated that the triple helical structure of the collagen composite film was not damaged, and compared with the pure collagen film, the mechanical properties, thermal stability, resistance to enzymatic degradation and hydrophilicity of composite films were improved, with the structures of the composite films being more homogeneous and compact. When the oxidation degree of DHPMC was low (oxidation degree: 17.78%), the aldehyde groups of DHPMC molecules formed covalent bonds with the amino groups of collagen to enhance the interaction of the system. In addition, the low oxidation degree of DHPMC had little effect on the film’s properties, resulting in improved tensile strength (115.74 MPa) and thermal denaturation temperature (76.24 ℃) of the composite films compared with collagen/ hydroxypropyl methylcellulose (HPMC) composite film (104.69 MPa, 69.67 ℃). When the oxidation degree of DHPMC was higher (45.12%), DHPMC contained more aldehyde groups, whilst the degree of cellulose degradation also increased, causing the decreases in the tensile strength (93.56 MPa) and thermal denaturation temperature (71.13 ℃) of the composite film. Thus, the composite films prepared by blending DHPMC with a low oxidation degree and collagen showed better overall film-forming properties, which would expand their applications in food packaging.

国家自然科学基金资助项目（21776184；21476147）