天然彩丝的结构和性能

 采用红外光谱、X射线衍射、氨基酸分析、扫描电镜、热重分析、力学性能测试等手段对天然彩丝的结构和性能进行分析，并与普通蚕丝进行比较。研究表明:天然彩丝纤维较普通白蚕丝细；天然彩丝的平均断裂强度为3.54 cN/dtex、弹性模量为76.7 cN/dtex、断裂伸长率为17.5%、其截面形状和纵向形态与普通白蚕丝无明显区别；天然彩丝的结晶度为44.4%，比普通白蚕丝低；天然彩丝的丝素分子和普通白蚕丝一样也存在酰胺Ⅰ、酰胺Ⅱ、酰胺Ⅲ、酰胺Ⅴ，分子结构中存在无规卷曲结构、β-折叠结构和α-螺旋结构。

Structure and properties of naturally colored silk

The structure and properties of naturally colored silk were investigated and compared with ordinary silk by amino acid analysis,infrared spectroscopy,X-ray diffraction,thermogravity analysis,scanning electron microscope,mechanical properties test.The results show that the naturally colored silk fiber is finer than the ordinary one,the average breaking tenacity of the naturally colored silk is 3.54 cN/dtex,the modulus of elasticity is 76.7 cN/dtex,and breaking elongation is 17.5%.The shapes of section and verticality are almost the same as the ordinary silk.The crystallinity of naturally colored silk is 44.4 %,lower than that of the ordinary one.Like the ordinary silk,amide Ⅰ,amide Ⅱ,amide Ⅲ and amide Ⅴ exist in fibroin molecules of naturally colored silk.The naturally colored silk has the structure of random coil,β-sheet and α-helix.