The Preparation And Performance Evaluation Of A Self-healing Electrorheological Elastomer

The electrorheological elastomer has controllable mechanical and electrical properties under the electric field.Due to the existence of its electrorheological effect,the electrorheological elastomer has been widely used in the intelligent control of shock absorbing devices,and will have a more realistic application prospects in the field of artificial muscle.As the complexity of biomuscular,the single controllable mechanical property for electrorheological elastomers has failed to meet the more intelligent requirements of imitating biomuscle actuators or biomuscle materials.In the view of biology,biomuscles have their own ability to heal in addition to the ability of the brain to control their muscle contractions.From the perspective of bionics,if artificial muscle materials have both controlled mechanical properties and autonomous healing capabilities,they can be closer to the ideal biomuscle material.It will provide a possible way to overcome this difficulty if the function of self-healing is imparted to the electrorheological elastomer.But there is no report on this kind of multifunctional intelligent artificial muscle material at present.In this paper,a network of polydimethylsiloxane?PDMS?polymer chains crosslinked by metal-ligand coordination that combines high stretchability and autonomous self-healing properties.The cross-linking sites coordination adopted Zn?II?as the central ion,coordinated with 2,6-pyridinedicarboxamide ligand to form Zn²⁺-ligand bond which can readily break and reform.In addition,a higher dielectricity TiO₂ particles were incorporated in this network of PDMS synthesizing an electrorheological elastomer with self-healing function,which provides a feasible method for the study of multifunctional artificial muscle driver or artificial muscle materials.The main research contents of this paper are as follows:1.Using Zn?II?as the central metal ion to form metal-ligand structure with2,6-pyridinedicarbonamideligandandincorporatingPDMSnetworktoobtain Zn²⁺-pdca-PDMS self-healing polymer elastomer.Using UV-vis absorption spectra,FT-IR spectra,NMR spectra and XPS spectra characterized the structure of the polymer network and bringing forward polymer network model and self-healing mechanism.2.The healing properties and dynamic viscoelasticity of Zn²⁺-pdca-PDMS wereevaluated by tensile test and rheological test.The results indicates that this polymer elastomer has autonomous self-repairing properties under normal temperature conditions,and thehealing efficiency can reach 80%at 45°C.The tensile test also shows that the elongation can reach 4500%at a low draw rate.The rheological test results show that the“hard and soft”properties of the elastomer can be adjusted by changing the metal-ligand ratio in the polymer network.3.A Zn²⁺-pdca-PDMS/TiO₂ electrorheological elastomer with self-healing function was prepared by incorporating TiO₂ particles into the Zn²⁺-pdca-PDMS polymer matrix under electric field.Tensile and viscoelasticity test showed that the Zn²⁺-pdca-PDMS/TiO₂elastomer still have autonomous self-healing ability,and the current change performance test showed that the relative ER effects achieve by 240%when the electric field strength was increased from no electric field to 4 kV/mm.