羧甲基纤维素钠改性角蛋白膜的结构与性能

Structure and properties of keratin film modified by carboxymethyl cellulose sodium

为改善羊毛角蛋白的成膜性能,以羧甲基纤维素钠(CMCNa)为改性剂,将其与羊毛角蛋白进行共混制备改性羊毛角蛋白膜。借助激光显微镜、红外光谱仪、X射线衍射仪以及热性能分析仪等对羧甲基纤维素钠改性膜的结构与性能进行表征。结果表明:经CMCNa改性的羊毛角蛋白膜,其结构更加致密,热稳定性和疏水性增强,伸长率由未改性前的1.8%增加至6.4%;改性羊毛角蛋白膜在水中的降解性由原来的20.4%增加至78.6%,但其强度由原来的35 MPa降低至16.3 MPa;CMCNa与羊毛角蛋白在共混过程中由于氢键的相互作用,降低了角蛋白的分子内氢键作用力,同时CMCNa的加入使羊毛角蛋白膜的结晶结构由原来的α-螺旋结晶结构转变为α-螺旋和β-折叠共存的结晶结构。

In order to improve film-forming properties of keratin, carboxymethyl cellulose sodium (CMCNa) was used as the modifier and blended with wool keratin to prepare a wool keratin film. The performances of the modified film were characterized by laser microscopy, infrared spectroscopy, X-ray diffraction, thermal properties, etc. The results indicate that the addition of CMCNa makes the structure of keratin membrane much denser, and improves its thermal stability and hydrophobicity. Moreover, its elongation increases from 1.8% to 6.4%, and its degradation in water also increases from 20.4% to 78.6%. However, its strengthen decreases from 35 MPa to 16.3 MPa. The reason is that inter-molecular hydrogen bond interaction between CMCNa and keratin occurs during the blending process, which reduces the intra-molecular hydrogen bonding of keratin. Further, with the addition of CMCNa, the crystal structure of modified membrane changes from the alpha-helical structure of wool keratin to the structure of both alpha-helical and beta-folded crystals.