Preparation And Properties Of Electric-sensitive Shape Memory Material

Three novel electro-and thermo-sensitive shape memory materials, metal fiber (NF)/ polycaprolactone (PCL), short carbon fiber (SCF)/PCL and carbon black (CB)/PCL conductive composites, have been prepared. The electro-induced shape memory properties, the mechanical properties, the electrical properties, the gel content, the recovery stress and the thermal induced shape memory effect of the composites are measured respectively. Then the effects of the gel content and the electrical properties on the electro-induced shape memory properties of the composites are investigated.The results show that the electro-induced shape memory effect depends on the thermal induced shape memory effect as well as the electro-thermal effect. For the NF/PCL, the electro-thermal effect is zero, and then the NF/PCL can't present the electro-induced shape memory effect. For the CF/PCL composites, the electro-induced shape memory effect is not good due to the uneven electro-thermal effect. However, for the CB/PCL composites, only CB200/25 and CB300/25 have both good thermal induced shape memory effect and good electro-thermal effect, thus they have excellent electro-induced shape memory effect. For the CB200/25 sample, under a voltage potential of 200 V, the shape recovery ratio is nearly 100% and the responsive time is less than 3 minutes.In addition, the gel content of the composite increases with the increase of radiation dose and the higher the gel content is, the better the thermal induced shape memory effect is. The conductivity increases with the increase in filler content for both the SCF/PCL and the CB/PCL. When heating up, the PTC effect can be observed for the SCF/PCL and the PTC/NTC effect can be observed for the CB/PCL. The recovery stress depends on the cross-linking degree and the stretch times, the more the cross-linking degree and the tensile times are, the greater the recoverystress is.