循环应力作用对皮革热稳定性的影响

Influence of cyclic stress on leather thermostability

在常压干燥下,对经复鞣加脂的牛坯革施加不同模式的循环拉伸作用,研究干燥时不同模式拉伸作用对皮革耐湿热性能、耐干热性能和热降解性能的影响,并通过傅里叶变换红外光谱法探讨皮胶原纤维内部氢键的变化。结果表明:干燥时拉伸往往会伴随氢键的断裂,从而降低试样的耐湿热性能。交替拉伸对皮革湿热稳定性影响最大,循环应力作用后的皮革耐干热性优于全拉伸的(干燥中持续拉伸不释放)。

Different cyclic stress was applied to cattle crust leather after retanning and fatliquoring under ambient pressure drying condition. The influence of different cyclic stress on the hydrothermal stability, dry heat resistance and thermal degradation ability of leather was studied. The changes of hydrogen bonds in collagen fibers were dis- cussed with Fourier transform infrared spectroscopy. Results show that stretching while being dried is accompanied with the fracture of hydrogen bonds, resulting in decreasing of hydrothermal stability of leather. Specifically, alterna- ting stress has the most significant effect on the hydrothermal stability of leather. Leather that after cyclic stress may receive better dry heat resistance than that constantly stretched while being dried.