The effect of iron oxide nanoparticles on the mechanical relaxation of magnetic polymer hybrid films composed of a polystyrene matrix, a fractional calculus approach

Abstract

A magnetic polymer hybrid film (MPHF) with a thickness of ~80 μm, composed of iron oxide nanoparticles (IONPs) in a polystyrene (PS) matrix, was successfully prepared. Its structure and morphology were analyzed by HRTEM, XRD, and FTIR. The optical and magnetic behaviors were studied by UV–Vis spectroscopy and VSM, respectively. The main relaxation of the MPHF was characterized by dynamic mechanical analysis (DMA), and the molecular mobility was analyzed by a fractional Zener model (FZM). Results obtained by DMA reveal the mechanical manifestation of the α‐relaxation for both, PS and MPHF, and how this process is modified by IONPs into MPHFs. Good agreement between experimental DMA spectra and the theoretical results calculated from the FZM was obtained. Fractional parameters a and b characterize the molecular mobility at low and high temperatures, respectively. These results show that at low temperatures ( a parameter), molecular mobility is slightly affected by the presence of IONPs, while at high temperatures ( b parameter), molecular mobility is affected in a greater degree. IONPs decrease the molecular mobility of PS matrix; this effect is more pronounced at temperatures above the glass transition temperature. These results validate the effect of IONPs on PS matrix considering future applications of the MPHFs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47840.

Synthesis of iron oxide nanoparticles encapsulated poly(styrene‐co‐4‐vinyl pyridine) nanocomposites for column adsorption and photocatalytic degradation of para nitrophenol from water

“…The composite copolymer (PMNC4) also shows this peak with two additional weak absorption peaks due to IONs present in the composite. In Figure 2C these are observed at around 360 nm due to the direct electronic transition from 2p orbital of O 2 − anion to 3d orbital of Fe 3+ and in the visible range in between 400 and 500 nm due to indirect 3d–3d charge transfer as reported elsewhere 33 . It is also observed that with the increase in the mol% of 4VP in the following order PMNC9(6.2%) < PMNC2 (9.1%) < PMNC4 (16.7%) as also shown in Table 1, the intensity of the absorption peaks due to IONs also increases.…”

“…In Figure 2C these are observed at around 360 nm due to the direct electronic transition from 2p orbital of O 2 À anion to 3d orbital of Fe 3+ and in the visible range in between 400 and 500 nm due to indirect 3d-3d charge transfer as reported elsewhere. 33 It is also observed that with the increase in the mol% of 4VP in the following order PMNC9(6.2%) < PMNC2 (9.1%) < PMNC4 (16.7%) as also shown in Table 1, the intensity of the absorption peaks due to IONs also increases. In fact, the pyridine moiety promotes the formation and entrapment of ION in the copolymer by hydrogen bonding interaction and complexation reaction.…”

“…The UV–vis absorption spectra of the polymers are shown in Figure 2C. The unfilled copolymer, that is, CP shows an absorption spectrum at around 260 nm due to the phenyl 33 and pyridine 34 functionality of the styrene and 4VP moiety, respectively of the copolymer. The composite copolymer (PMNC4) also shows this peak with two additional weak absorption peaks due to IONs present in the composite.…”

Correlation between the mechanical and dielectric responses in polymer films by a fractional calculus approach

“…This is because these applications are useful characteristics of low cost, lightweight, ease of manufacture, versatility, thermal efficiency, durability, low distortion, and moisture resistance 9 . Besides, from an electrical point of view, polystyrene films provide high insulation, low leakage, low dielectric absorption, and excellent temperature stability 10,11 . From a scientific point of view, Perov proposed to use PS films for the study of polymer relaxation phenomena 12 .…”

Thermomechanical Characterization and Modeling of NiTi Shape Memory Alloy Coil Spring

“…To obtain a rheological model capable of describing experimental results, the classical Zener model is modified with two springpots to obtain the so-called Fractional Zener Model or FZM (see Figure 2 ). It has been reported that the fractional order parameters of the FZM are related to the cooperative molecular mobility of the mechanical relaxation phenomena in polymers [ 19 , 24 , 25 ]. Puente-Córdova et al [ 26 ] reported the use of the FZM to model the viscoelastic behavior of isotropic and anisotropic magnetorheological elastomers.…”