Synthesis and characterization of novel piezoelectric nitrile copolyimide films for high temperature sensor applications

Abstract

A series of amorphous polyimides and copolyimides that contained nitrile were obtained by a two-step procedure. The first step consisted of a polycondensation reaction of 4,4'-oxydiphtalic anhydride (ODPA) with one or two aromatic diamines, namely 1,3-Bis-2-cyano-3-(3aminophenoxy)phenoxybenzene (diamine 2CN) and 1,3-Bis(3-aminophenoxy)benzene (diamine 0CN). In the second step, a thermal cyclodehydration converted each poly(amic acid) or copoly (amic acid) into their corresponding polyimide films. The piezoelectric response was improved after corona poling of the films. A maximum d 33 modulus value of 16 pC N −1 was obtained for the polymide with two cyano groups (poly 2CN). The polarization also showed time and thermal stability up to 160 °C. Additionally, the thermal stability of the amorphous polyimides, (β-CN) APB/ODPA, was studied by determining the glass transition temperature (T g ) and thermal decomposition through differential scanning calorimetry (DSC) and thermogravimetric analysis (TG), respectively. The high piezoelectric response (1-16 pC N −1 ), T g (160-180 °C) and degradation temperature (315-450 °C) make such polyamides excellent candidates for use as high temperature sensors.

Effect of cyano dipolar groups on the performance of lithium-ion battery electrospun polyimide gel electrolyte membranes

“…Table 1 summarizes the average fiber diameter and degree of porosity for the different samples. (table 2), which is lower than the one reported in [33] for polymer films. It was reported that the high electric field used to obtain electrospun fibers can lead to polymer chain alignment along the longitudinal direction of the polymer fiber [34], which in turn can influence the glass transition temperature of the polymer, as demonstrated for poly(vinyl alcohol) (PVA) [35].…”

“…Nevertheless, just a slight change from 178 ºC in 0CN and 176 ºC in 2CN from bulk polymer [33] down to 176 ºC and 174 ºC (table 2) in 0CN and 2CN electrospun fibers, respectively, was observed. On the other hand, a strong decrease of T g is observed in the 0CN/2CN (50/50 w/w) copolymer sample, which can be related to polymer chain [35] and amorphous regions confinement [37] in the copolymer due to the different nature of the polymer phases with and without CN-dipolar groups.…”

Metallic Glass/PVDF Magnetoelectric Laminates for Resonant Sensors and Actuators: A Review

“…They are usually obtained by reaction between the dianhydride ODPA and a 50% mol mixture of two aromatic diamines, namely 1,3-bis-2-cyano-3-(3-aminophenoxy)- phenoxybenzene (diamine 2CN, good piezoelectric behavior) and 1,3-bis(3-aminophenoxy)benzene (diamine 0CN, good mechanical behavior) in a two-step reaction. Extensive information about the synthesis, mechanical and dielectric and properties of these copolyimides can be found in [54,55]. Several test were performed concerning the ME response of such metallic glass/piezopolymer/metallic glass, being metallic glass = Vitrovac 4040 or home-made amorphous ribbons, and piezopolymer = PVDF or the 2,6( β -CN) polyimide or other copolyimides [15,56].…”

Novel piezoelectric properties of electrospun polyamide-imide nanofiber membranes

“…For instance, the operational temperature of piezoelectric PVDF is below 85 °C. 51,52 Above this critical temperature, the piezoelectricity decreases rapidly. To overcome this constraint, polyimides (PIs) were examined.…”