Piezoelectric and mechanical behavior of NaNbO3/PEKK lead-free nanocomposites

Abstract

a b s t r a c tLead-free piezoelectric nanocomposites based on poly(ether ketone ketone) (PEKK) and sodium niobate (NaNbO 3 ) particles were elaborated. The presence of submicronic particles does not influence the thermal stability of the matrix so that no degradation phenomenon is observed before 500°C. The conservative mechanical modulus G′ increases linearly with the NaNbO 3 fraction; this variation is well fitted by the Kerner model until 20 vol%. Such nanocomposites remain ductile. The polarizing field required for obtaining piezoelectric nanocomposites is 12 kV·mm −1 i.e. analogous with the one used for poling bulk ceramic. The value of the piezoelectric coefficient (d 33 = 0.2 pC·N −-1 for 20 vol% NaNbO 3 ) is consistent with the Furukawa's model. This value is explained by the low PEKK permittivity. This low d 33 is counterbalanced by the piezoelectric voltage constant (g 33 = 103·10 −3 Vm·N −1 ) which is higher than the one of classical piezoelectric ceramic like PZT or BaTiO .

Electrical behavior of a graphene/PEKK and carbon black/PEKK nanocomposites in the vicinity of the percolation threshold

“…7 shows the PEKK thermogram over ail the temperature range. The study of the mechanical relaxations have been extensively detailed in a previous paper [ 48].…”

Nickel‐Decorated Silver Nanowires for Polymer‐Based Magnetoelectric Composite

“…Second, as P(VDF‐TrFE) is on the rubbery plateau at room temperature, the Ag@Ni NWs’ presence induces additional topological nodes, which increase the rubbery mechanical modulus. It has been previously shown that such modulus increase leads to a transduction/dissipation phenomenon and d 33 coefficient [ 34 ] decrease. This phenomenon coupled with a lower effective field caused by dielectrical losses and a lower crystallinity ratio explains such a d 33 decrease.…”

Effect of PEKK oligomers sizing on the dynamic mechanical behavior of poly(ether ketone ketone)/carbon fiber composites

“…We observe an increase of 27% for the unsized composite compared to the matrix. This energy loss mechanism involves a stick–slip effect . This effect which is present in a wide range of composites, indicates a specific dissipative energy due to the creation and disruption of physical bonds between the matrix and the fibrous reinforcement.…”

“…This energy loss mechanism involves a stick-slip effect. 21,[39][40][41] This effect which is present in a wide range of composites, indicates a specific dissipative energy due to the creation and disruption of physical bonds between the matrix and the fibrous reinforcement. Figure 6 represents tan δ as a function of temperature for the unsized composite ( ), and the PEKK matrix ( ).…”