热塑性聚氨酯共混物的硬度与冲击性能的关系北大核心CSCD

选取了2种分子组成相同硬度不同的热塑性聚氨酯(TPU),将二者共混后得到了不同硬度的TPU共混物,探究了TPU共混物的硬度与冲击性能的关系。通过落球冲击试验、感压纸测试和冲击前后样品表面温度测试对TPU共混物的冲击性能进行表征。当样品的硬度越低时,峰值冲击力越小,冲击持续时间越长,冲击时的最大应变越大,冲击时样品的受力面积增大,对应的冲击时的峰值应力值减小。不同硬度样品的能量耗散比差别不大,但随硬度降低呈现小幅度上升趋势。冲击后的样品表面温度较冲击前有所上升,说明样品通过热的形式耗散了部分能量,各硬度样品的温度差值较为接近,这与不同硬度样品的能量耗散比的变化规律是相似的。所有样品均具有较高的能量耗散比,TPU能耗散大部分冲击能量,具有良好的抗冲击性能。

Relationship Between Hardness and Impact Properties of Thermoplastic Polyurethane Blends

Two kinds of thermoplastic polyurethanes （TPUs） with the same molecular composition and different hardness are used to prepare TPU blends with different hardness. The relationship between the hardness and impact properties of TPU blends is investigated. The impact properties of TPU blends are characterized by the falling ball impact test， pressure sensitive paper test and sample surface temperature test before and after impact. When the hardness of the sample is lower， the peak impact force is smaller， the impact duration is longer， the maximum strain of the sample is larger， the maximum impact area of the sample increases， and the value of maximum stress decreases. The energy dissipation ratio of samples with different hardness has little difference， but it shows a trend of slight increase with the decrease of hardness. The surface temperature of samples after impact increases compared with that before impact， indicating that part of energy is dissipated by heat. The temperature difference of samples with different hardness is similar， which is similar to the change of energy dissipation ratio of samples. All samples have high energy dissipation ratios. TPU can dissipate most of the impact energy， and has good impact resistance.