聚氨酯弹性体电致伸缩特性

Electrostrictive properties of polyurethane elastomers

为了提高材料的电致伸缩特性,通过原位共聚合法在聚氨酯弹性体(PUE)中掺入了不同质量比例的纳米钛酸钡.采用LCR测试仪、邵氏硬度计和电容法电致伸缩特性测试装置研究了纳米钛酸钡掺杂对PUE的影响.试验结果表明:随着掺杂比例的提高,PUE的介电系数和硬度增加,回复速度变差;较低的掺杂能提高PUE的电致伸缩应变,过高的掺杂导致PUE电致伸缩特性下降,掺杂6%钛酸钡的PUE表现出最佳电致伸缩应变.进一步对PUE电致伸缩特性因素进行了理论分析并提出了电致伸缩弹性体电荷迁移逾渗模型,其很好地解释了电致伸缩材料弯曲、临界电场反转膨胀、高掺杂回弹等现象.

For increasing the electrostrictive properties of materials, different mass proportion BaTiO3/polyurethane nanocomposite elastomers（PUE） are prepared. LCR test instrument, Shore hard- ness test instrument and capacitive electrostrictive properties test device are used to test the effect of doped PUE. The results show that, with the increase of doped proportion, the dielectric constant and the hardness increase but restoration speed decreases. It is found that low content doping can increase the electrostrictive strain of the PUE, while more doping will depress the electrostrictive strain. PUE with 6% content shows a greastest electrostrictive strain. The charge transference percolation model （CTPM） is proposed which can explain bending, critical electric field reverse expanding, and high doping spring phenomena of BaTiO3/PU nanocomposite elastomers.