兔胸主动脉在冻结状态下力学性能的实验研究

Experimental study on the mechanical properties of frozen rabbit aorta

采用动态机械分析仪(DMA)研究了不同的温度点、降温速率以及低温保护剂浓度对兔胸主动脉在冻结状态下力学性能的的影响.研究结果表明,未经二甲基亚砜(DMSO)处理过的主动脉血管在-50℃的断裂强度(11.62±0.51MPa)和弹性模量(2670±1360MPa)均明显比-20℃时的断裂强度(8.71±0.44MPa)和弹性模量(37.1±4.65MPa)大,而且也要略高于-80℃时的断裂强度(10.18±3.2MPa)和弹性模量(2050±690MPa);以20℃/min降温时的弹性模量略低于5℃/min降温时的弹性模量,但其断裂强度反而略高;随着DMSO浓度增大,弹性模量显著减小,而且其断裂强度也会逐渐减小,但当DMSO浓度增大到一定值时,这种变化不再明显.

To obtain the mechanical properties parameters for frozen rabbit aorta, the effects of temperatures, cooling rates and cryoprotective agent's concentrations on the mechanical properties of frozen rabbit aorta were investigated with Dynamical Mechanical Analyser (DMA2980). The experimental results show that the fracture strength and elastic modulus of rabbit aorta without MDSO at-50°C are obviously higher than those at-20°C, and also a bit higher than those at-80°C; the elastic modulus with the cooling rate of 20°C/min is a bit lower than that with the cooling rate of 5°C/min, but the fracture strength is in reverse; with the increasing concentration of DMSO, the elastic modulus decreases markedly, and the fracture strength will also become smaller gradually, however, this change will be no more obvious when the concentration of DMSO rises to some point (e.g. 10%).