Mechanisms analysis of thermoplastic polyurethane (TPU)-poly(vinylidene fluoride) (PVDF) blends subjected to shock wave loading

Thermodynamically incompatible mixtures, thermoplastic polyurethane/poly(vinylidene fluoride) (TPU/PVDF) blends, were designed and fabricated in this work. Micro parameters including free fraction volume (FFV), ratio of surface area to volume (S/V) and binding energy (E_b) were calculated by simulation. Shock wave mitigation ability of TPU and its blends was investigated by using TNT in air free field. Overall, TPU blends showed a stronger shock wave attenuation capability than neat TPU. TPUP-10, the addition amount of PVDF in TPU matrix is 10 wt%, with thickness of 1 mm and 3 mm presented the lowest pressure value and pressure attenuation rate achieved 86.9 %, 95.3 %, respectively. With thickness of 5 mm, the pressure attenuation rate of TPU-10 reached 96.4 %. Pearson correlation analysis showed that FFV and S/V with thickness of 1 mm and 3 mm had significant effect on wave mitigation, while there is little relation with mechanical parameters. With increasing of thickness, the correlation with FFV is weaker whereas the mechanical property parameters are stronger. This study provides a better insight into designing of shock wave mitigation materials.