Abstract
In this study, the viscoelasticity of PVA/[BMI]Cl composites in the absence and presence of US was
tested using a rheometer equipped with an ultrasonic system. PVA/[BMI]Cl composites were prepared by
mixing PVAs with different molecular weights and [BMI]Cl synthesized from 1-methylimidazole and
1-chlorobutane. A constant frequency of 1Hz and a constant strain of 1% were applied in this experiment for
the viscoelasticy. The samples of the PVA/[BMI]Cl composite were exposed to 43kHz of US with a power of
12.5W at 25℃ for 5min, and then US was stopped. By irradiating the US, storage moduli G′ and loss moduli
G″ decreased in the whole composites. Moreover, the values of G′ and G″ were returned to the original value
after US stopped. This behavior was seen in the second and third cycles. The value of tan δ = G″/G′ refracted
the gelatinous property of the material and increased under US exposure. The increase in the value of tan δ
indicated that these four composites behaved much more like liquid under US.
