丝素/水性聚氨酯膜的制备及表征

首次采用丝素粉体和水性聚氨酯按不同比例混合,经热压法成功制备出丝素/聚氨酯共混薄膜。红外光谱、X-射线衍射、动态力学分析及拉伸实验结果表明：聚氨酯的加入,促进了丝素蛋白分子β-折叠结构的形成,导致丝素结晶度提高;丝素含量越大,共混膜中聚氨酯的玻璃化温度越低,共混膜的拉伸断裂强度和初始模量越高;当丝素含量从0到70%变化时,试片的断裂强度由0.6MPa增大到10.4MPa,断裂伸长率从1065%下降到47.5%。聚氨酯的加入改善了共混膜的弹性,韧性随聚氨酯含量的增大而增大。

Preparation and Characterization of the Blended Film of Silk Fibroin and Polyurethane

Utilizing waterborne polyurethane as a plasticizer, for the first time, we prepared the blended films of silk fibroin powder and polyurethane by hot-pressed method. The structure of＇the blend was analyzed by means of FTIR spectrum and wide-angle X-ray diffraction. The miscibility and properties of the blended materials were characterized by dynamic mechanical analysis and tensile testing. The results indicated that the introduction of polyurethane enhanced the contents of the β - sheet of silk fibroin in the blend. Moreover, the tensile strength and Young＇ s modulus increased with increase of silk fibroin content. With an increase of SF content from 0 to 70wt%, the tensile Strength of the sheets increased from 0.6 MPa to10.4 MPa, and the elongation at break value of the sheets decreased from 3211% to 47.5%. WPU as a plasticizer can play an important role in improving the properties of silk fibroin materials.