Preparation And Evaluation Of Electro-induced Shape Memory Epoxies

Electro-induced SMP is a kind of Shape Memory Polymer composites, whose shape memory effect cannot be described well by any existing polymer material theory model. Electricity as a stimulus enables actuation of electro-induced SMP. In this way, external heating, which is unfavorable for many applications and is used to stimulate conventional shape memory polymers, can be avoided. The electric triggering of SMP composites enlarges their technological potential. Therefore, electro-induced SMP has potentialities in the areas of space structure in further, but study is just in the junior stage.In the paper, raw materials are resin and curing additives, which translate into shape memory epoxies through cross-linking reaction. Then electro-induced SMP was prepared by blending process, which use SMP as matrix and carbon black as electric conductive filler. In this research, preparation in detail and SMP performance tests are carried out for electro-induced SMPs, through a series of experiments, including stress cycles and stress relaxation test, creeping test. It is investigated how content of carbon black affect properties of the composites. In summarizing the predecessors’research results, the main achievements and conclusions are obtained as follows:1. Four types of electro-induced SMPs with different contents of carbon black and the same content of curing agent, are prepared by epoxy resin E-51, curing additives DDM and conductive carbon black, which produce chemical cross-linking reaction.2. Froze and recovery experiments are performed on these prepared SMPs. Through the analysis, their shape fixture rate and shape memory properties are good. With increase of contents of carbon black, the glass transition Tg of the SMPs decrease.3. Stress cycles and stress relaxation test, creeping test are performed at different temperatures on these prepared SMPs. Elastic modulus and viscoelasticity are analyzed. The results show that with the increase of temperature, the elastic modulus of every specimen decrease. With the increase of carbon black contents, the viscoelasticity of SMP composites decrease.4. Conductivity of five types of electro-induced SMPs with different contents of carbon black is investigated, and it is concluded that percolation threshold of carbon black is between20%and25%.The researching results of the paper provide good reference to the application in industry in further.