Sage Journals: Discover world-class research

Abstract

The current article aims to develop poly (butyl methacrylate) (PBMA) nanocomposites with enhanced electrical and mechanical properties by incorporating neodymium oxide (Nd₂O₃) nanoparticles between the PBMA chains. The morphological, thermal and structural profiles of the PBMA nanocomposites reinforced with different loading of Nd₂O₃ nanoparticles were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The SEM images revealed that the morphology of the PBMA was significantly influenced by the insertion of Nd₂O₃. The uniform dispersion of Nd₂O₃ in the polymer composite was visible at 5 wt% loading of nano-filler. The main crystalline peaks of Nd₂O₃ nanoparticles in the amorphous PBMA structure were revealed by the X-ray diffraction analysis. The thermal stability of PBMA was greatly enhanced by the dispersion of Nd₂O₃ in the PBMA matrix. The tensile strength and elongation at break of the composites were measured and both results showed the enhanced mechanical properties of PBMA due to the reinforcement of Nd₂O₃ nanoparticles. The various parameters affecting the increased tensile strength of composite by the incorporation of nanoparticles were studied by different theoretical modeling. The electrical properties such as dielectric constant and the dielectric loss tangent (tan δ) of PBMA nanocomposites were enhanced with the addition of nanoparticles. Also, the DC conductivity of polymer composites was estimated and the applicability of different theoretical models for predicting the conductivity properties of PBMA/Nd₂O₃ nanocomposites were examined.

Keywords

Poly (butyl methacrylate)neodymium oxide nanocomposites X-ray diffraction tensile strength DC conductivity theoretical modeling

Introduction

Polymer composites offer numerous applications in technical fields due to their unique physical and chemical properties as well as their easy processability.^1–4 To improve the properties of composites, metal oxide nanoparticles with specific properties are incorporated into the polymer matrix which resulted in polymer nanocomposites with salient features.^5,6 Compared to conventional metal oxides, the nanosized metal oxide provides a higher interaction zone to the polymer matrix which results in the significant improvement in mechanical properties of the polymer composites.^7,8 However, the mechanical properties are significantly influenced by the size, shape, amount as well as the nature of the nanoparticles within the polymer matrix. Du et al. has investigated the role of MgCl₂ nanoparticles for improving the mechanical properties of polyvinyl alcohol polymer.⁹ The significantly improved optical properties of PMMA polymer by the dispersion of ZnO nanoparticles were reported by Demir et al.¹⁰ Improved conductivity properties of PMMA polymer by the addition of CeO₂ nanoparticles were reported by Rajendran et al.¹¹

Recently, polymer nanocomposites with remarkable mechanical and electrical properties have great attention due to their interesting applications. Semiconducting metal oxide nanoparticles are used as a reinforcing filler for the fabrication of polymer nanocomposite. The incorporation of these nanoparticles into the polymer matrix enhances the mechanical strength and electrical properties of polymer composite. Among various semiconducting metal oxides, rare earth metal oxides are more interesting due to their immense optical and electrical properties.^12,13 Neodymium oxide is an important rare earth metal oxide widely used in various electronic applications due to its low band gap energy and variable valence states.¹⁴ The lightweight polymers with transparent nature have attracted the researchers due to their potential applications in various fields. In automotive and aircraft industries, the materials with lightweight and substantial mechanical properties are more preferred. Therefore poly (butyl methacrylate) polymers are widely studied nowadays, owing to its flexible, transparent and better mechanical properties.^15,16 Further, the properties of PBMA can be improved by adding suitable nanoparticles in order to extend their applications to various fields.

The mechanical and electrical properties of polymers are greatly enhanced by the proper insertion of nanoparticles. In such polymer composites, a drastic increase in properties is obtained at certain filler loadings and beyond this loading these properties are decreasing. The changes in mechanical properties are explained on the basis of strong synergistic effects between the polymer and the nanoparticles.¹⁷ The Experimental data and theoretical studies are important for explaining the mechanism behind mechanical and electrical properties of polymer composites. The fillers act as stress-relieving sites at the polymer-filler interface which is responsible for higher mechanical properties of polymer composites.^18,19 Generally, the electrical properties of such composite depend on the aspect ratio, volume fraction of filler, nature and polarity of the filler.^20–22 Several theoretical studies are carried out to analyze the mechanism of conductivity and tensile strength of polymer composite. Based on this, the present study is focused on the experimental and theoretical studies of electrical properties and mechanical strength of PBMA with different contents of Nd₂O₃ nanoparticles through free radical polymerization technique. To the best of our knowledge, there is no work reported on the effect of Nd₂O₃ nanoparticles on the mechanical and electrical properties of PBMA. The influence of Nd₂O₃ nanoparticles on the tensile strength as well as DC conductivity of the PBMA matrix are studied in detail with respect to different loading of nanoparticles.

Experimental

Materials and methods

n-Butyl methacrylate (HiMedia), neodymium nitrate hexahydrate (Nd(NO₃)₃.6H₂O (Aldrich), azobisisobutyronitrile (AIBN-HiMedia), cetyltrimethyl ammonium bromide (CTAB-HiMedia), toluene and ethanol were the chemicals used for the present study.

Synthesis of PBMA/Nd₂O₃ nanocomposites

Poly (butyl methacrylate)/ neodymium oxide nanocomposites were synthesized by the in-situ polymerization of butyl methacrylate monomer with different amount of neodymium oxide nanoparticles. The Nd₂O₃ nanoparticles were prepared by a simple co-precipitation technique as reported earlier.²³ For the preparation of nanocomposites, different contents of Nd₂O₃ nanoparticles (3, 5, 7 and 10 wt%) were first dispersed with CTAB in toluene to prevent the agglomeration of nanoparticles during in situ polymerization. The purified butyl methacrylate monomer (0.45 mol) was separately homogenized with toluene in a reaction kettle. Then the nanoparticle dispersion was added into butyl methacrylate monomer solution under constant stirring. The whole solution was subjected to ultrasonication to ensure the homogenous dispersion of nanoparticles into the monomer solution. AIBN (3.89 × 10⁻³ mol/L) in toluene was added to the above hybrid solution and the polymerization was carried out at 85°C for 2 h. The prepared polymer composite was separated from the homogenous solution by coagulating with ethanol, washed and dried to get constant weight. Neat poly (butyl methacrylate) was also prepared by the same experimental procedure except nanoparticles for a comparative study.

Characterization

The XRD patterns of Nd₂O₃ nanoparticle and the developed PBMA/Nd₂O₃ nanocomposites were recorded by Rigaku Miniflex 600 diffractometer (Japan). The diffractogram was measured at an operating 2θ range from 5° to 80° at a speed rate of 2° min⁻¹. The surface morphologies of all the samples were examined by a Hitachi S-3000 H scanning electron microscope after sputter coating of the fracture surface of the polymer with gold at 0° tilt angle. The tensile strength and elongation at break of the samples were measured by using Zwick Universal Testing Machine (UTM) ASTM D 412-80 at 28°C, and a crosshead speed of 500 mm/min. The tensile measurements were carried out five times for each sample and the average value is reported. The electrical properties of the samples were measured by using polymer sheets (circular shape of 0.3–0.5 mm thick, 1.2 cm diameter). The DC conductivity measurements were done using Keithley 2400 instruments at room temperature. The dielectric properties of the polymer nanocomposites were determined by the impedance analyzer (Hewlett–Packard LCR Meter) in the frequency range of 10²–10⁶ Hz at room temperature. The dielectric constant was calculated by the following equations

ε_{r} = \frac{C \cdot d}{ε_{0} \cdot A}

σ_{a c} = ε_{0} \cdot ε_{r} \cdot ω \cdot tan δ

where d implies the thickness of the sample, C the capacitance, A is the area of cross-section of the sample, $ε_{0}$ the permittivity of free space and $ε_{r}$ implies the relative permittivity (dielectric constant) of the material.

Results and discussion

Morphological studies

Surface morphological assessment of PBMA and PBMA with different contents of Nd₂O₃ nanoparticles are presented in Figure 1. The synthesized PBMA exhibited a homogenized smooth morphology which became coarser by the in-situ polymerization of Nd₂O₃ nanoparticles with butyl methacrylate monomer. The SEM picture of 3 wt% Nd₂O₃/PBMA nanocomposite showed an uneven distribution of nanoparticles in the polymer matrix with smooth morphology. It can be seen from the figure that the sample with 7 wt% nanoparticles containing PBMA shows a uniform structure with several uniformly dispersed nanoparticles which indicated a better adhesion between the polymer and the nanoparticles. The uniform dispersion of nanoparticles in the polymer is attributed to the strong interfacial interaction of PBMA with the Nd₂O₃ nanoparticles. However, the uniform dispersion of filler in the polymer is significantly changed into an agglomerated structure at higher loading of Nd₂O₃ nanoparticles (at 7 wt% loading). At higher loading, the coupling of adjacent nanoparticles increased the stress in the polymer composite which ultimately resulted in the clustering of nanoparticles.

Figure 1.

FESEM images of PBMA with various loading of Nd₂O_3.

XRD analysis

Structural information of the prepared PBMA and PBMA/Nd₂O₃ nanocomposites are analyzed by XRD and the results are presented in Figure 2. As seen in the figure, the synthesized PBMA exhibits an amorphous peak at 2θ = 17.65°. However, the XRD patterns of the composites are distinct from that of plain PBMA. The composite exhibits the characteristic crystalline peaks of Nd₂O₃ nanoparticles along with the amorphous peak of pure PBMA which implies better compatibility between the polymer matrix and nanoparticles.^24,25 It can be seen from the figure that the intensity of Nd₂O₃ peaks increases with the loading of nanoparticles in the polymer composite. The percentage of crystallinity induced by the addition of 5 and 10 wt% Nd₂O₃ nanoparticles into the polymer is found to be 50.01% and 54.21% respectively. The increase in the crystalline nature of composites signified the better reinforcement of Nd₂O₃ nanoparticles into the PBMA.

Figure 2.

XRD pattern of PBMA with various loading of Nd₂O_3.

Dielectric properties

The changes in electrical properties such as dielectric loss and dielectric constant of PBMA by the addition of Nd₂O₃ nanoparticles are measured at different frequencies 10² to 10⁶ Hz. Figure 3 shows the variation of dielectric loss (tan δ) value with frequency for the PBMA and PBMA/Nd₂O₃ nanocomposites. As seen from the figure, the dielectric loss value of all the composites decreases with frequency up to 10³ Hz and then it remains constant. However, the introduction of Nd₂O₃ nanoparticles increases the dielectric loss value indicate that the nanoparticles brought some modifications in the PBMA matrix obviously by the better interface between them.^26,27 But, in the present case, though the dielectric loss value increases with the addition of nanoparticles, the composites with 7 and 10 wt% Nd₂O₃ nanoparticles exhibit lower dielectric loss value than the PBMA with 5 wt% Nd₂O₃ nanoparticles. This might be due to poor polymer-filler interface by the presence of agglomerated nanoparticles at higher concentrations, as revealed from SEM images.

Figure 3.

Dielectric loss of PBMA with different content of Nd₂O_3.

The variation in dielectric constant (ε_r) with frequency for PBMA and PBMA/Nd₂O₃ nanocomposites is shown in Figure 4. The dielectric constant decreases with frequency in all cases up to 10⁴ Hz and after it remains independent of frequency. The higher value of dielectric constant at lower frequency is due to the proper alignment of polymer dipoles with the applied frequency. As the frequency increases the dipoles fail to arrange themselves with the applied frequency and so the dielectric constant remains independent of frequency.²⁸ But, interestingly the dielectric constant increases with the addition of Nd₂O₃ nanoparticles up to 5 wt% and after it shows a slight decrease in value. The contribution from space charge polarization arises due to the better interfacial interaction between the polymer and filler which results in higher dielectric constant for polymer composites.²⁹ The slight decrease in dielectric constant at higher loading of nanoparticles (7 and 10 wt%) is due to poor interface between the PBMA and Nd₂O₃ nanoparticles by the presence of aggregated nanoparticles.

Figure 4.

Dielectric constant of PBMA with different contents of Nd₂O_3.

Mechanical studies

Mechanical properties of polymer composites have a major role in the application of polymer products in many fields. In the present study, the tensile strength and elongation at break (EB) of the pure PBMA as well as PBMA/Nd₂O₃ nanocomposites are analyzed and the results are given in Table 1. The interfacial interaction and the extent of stress transfer plays a key role in improving the tensile properties of composites^29,30 and the schematic representation of the interaction of PBMA with Nd₂O₃ are given in Figure 5. The tensile strength of nanocomposite increases with the loading of nanoparticles up to 5 wt% loading. The incorporation of nanoparticles creates additional stress-bearing sites and therefore an effective stress transfer from the polymer matrix to the nanoparticles through the better interface between them.³¹ So, the increased tensile strength values for PBMA/Nd₂O₃ nanocomposites is attributed to the better reinforcement effect of Nd₂O₃ nanoparticles in the PBMA matrix. However, the maximum tensile strength of the composite decreased slightly beyond 5 wt% loading. The decrease in tensile strength at higher loading arises from the incomplete interface between the matrix and nanoparticles due to the presence of agglomerated particles, as revealed from SEM images. The EB of composite is found to decrease with the addition of Nd₂O₃ nanoparticles due to the presence of brittle nanoparticles in the polymeric chain.

Table 1.

Mechanical properties and DC conductivity of PBMA and PBMA/Nd₂O₃ nanocomposites.

Samples	Tensile strength (MPa)	Elongation at break (%)	DC conductivity (S/cm)
PBMA	22.72	59.87	4.23 × 10⁻¹²
PBMA/3 wt% Nd₂O₃	24.32	45.55	4.3 × 10⁻⁹
PBMA/5 wt% Nd₂O₃	27.59	44.62	5.9 × 10⁻⁹
PBMA/7 wt% Nd₂O₃	26.45	42.14	4.6 × 10⁻⁹
PBMA/10 wt% Nd₂O₃	25.92	40.32	4.4 × 10⁻⁹

Figure 5.

Interaction of Nd₂O₃ nanoparticles with PBMA.

Tensile modeling studies

Many theoretical equations are used to predict the effect of various factors (size, shape, aspect ratio, filler concentration, the extent of interfacial interaction between filler and polymer matrix) toward the improved tensile properties of polymer nanocomposites.^4,32 In the present work theoretical models suggested by Einstein, Mooney and Pukanszky equations are employed to predict the tensile properties of PBMA/Nd₂O₃ nanocomposites. The experimental value obtained from the tensile analysis is compared with the theoretical tensile strength to predict the reinforcing factors behind the enhanced mechanical properties of polymers.

Einstein model

Einstein suggested the following equation to predict the tensile properties of polymer composites.³³

M c = M m (1 + 2.5 Vf)

where Mc and Mm denote the tensile properties of composite and polymer matrix respectively and Vf denotes the filler volume fraction. The tensile strength of composites is applied to the Einstein equation and the theoretical tensile values are compared with experimental values and the results are given in Figure 6. It shows that the theoretical values based on Einstein model are found to be lower than the experimental tensile values. This is because the Einstein model is applicable to polymer composite at lower concentration of fillers (>1) and hence this model fails in most cases to predict the tensile mechanism of polymer composites.

Figure 6.

Theoretical and experimental curve of tensile strength based on Einstein model.

Mooney model

Mooney modified the Einstein equation by introducing a parameter “S” to make it suitable in all concentrations.³⁴ The value of “S” signifies the strain field around the polymer matrix and the filler. For filler particles the S = 1.35. The Mooney equation can be expressed as

M c = M m * exp [\frac{2.5 Vf}{1 - SVf}]

where, the parameters have their usual meanings as explained above. The tensile strength of PBMA/Nd₂O₃ nanocomposites is calculated using the Mooney equation and the results obtained are given in Figure 7 along with the experimental tensile value. The theoretical value using the Mooney equation and the experimental value shows a close match at lower filler concentrations, but the theoretical tensile values lie far away from that of experimental values at higher filler loading. Mooney model assumes that the filler and polymer matrix have comparable tensile values and so it fails in predicting the tensile properties especially in systems with large differences in tensile properties of components like PBMA/Nd₂O₃ nanocomposites.

Figure 7.

Theoretical and experimental curve of tensile strength based on Mooney model.

Pukanszky model

Pukanszky put forward a theoretical model for the polymer composite in which the interfacial interaction between the polymer matrix and filler plays a major role in the enhancement of tensile strength by the following equation.

M c = M m * \frac{1 - Vf}{1 + 2.5 Vf} * exp (Bvf)

where the parameter “B” determines the level of interfacial interaction between the polymer matrix and the filled nanoparticles. The value of B depends on the size and loading of filler as well as on the thickness and extent of interphase.^32,35 The correlation graph of experimental tensile value with that of theoretical value obtained using the Pukanszky model is shown in Figure 8. As clear from the figure, the Pukanszky model exhibits a better fit in the case of PBMA/Nd₂O₃ nanocomposites. Both the theoretical and experimental tensile values using the Pukanszky model shows a close match at entire filler loading. So, it can be concluded that the effective loading of filler in the polymer depends on the interfacial interaction between the PBMA and Nd₂O₃ nanoparticles and these interactions lead to the improved tensile properties of PBMA/Nd₂O₃nanocomposites.

Figure 8.

Theoretical and experimental curve of tensile strength based on Pukanszky model.

DC conductivity studies

Metal oxide nanoparticles, especially Nd₂O₃ nanoparticles having considerable semiconducting properties can impart good electrical properties to the insulating polymer. The variation in DC conductivity (σ_dc) of PBMA with different loading of Nd₂O₃ is presented in Table 1. It is clear that the σ_dc of PBMA is substantially improved by the addition of Nd₂O₃. Further, the σ_dc value is increasing with the loading of Nd₂O₃ nanoparticles. The conductivity of PBMA arises from the restricted movement of bipolaron charge centers under the applied voltage.³⁶ But in the case of composites there is a gradual formation of conducting network within the polymer matrix by the insertion of Nd₂O₃ nanoparticles, which results in higher conductivity of composites than the bare PBMA. Further the interfacial polarization at the interface between the nanoparticles and PBMA matrix further contributes to the enhanced conductivity of PBMA/Nd₂O₃ nanocomposites.³⁷ The maximum conductivity is obtained for PBMA with 5 wt% Nd₂O₃ and beyond the 5 wt% loading, the conductivity is slightly decreasing which might be due to the presence of agglomerated nanoparticles in the PBMA matrix.

Theoretical modeling of DC conductivity

Several theoretical models have been used to investigate the role of fillers in the conductive mechanism in a polymer matrix. These models have been formulated on the basis of various assumptions. The main focus of these models is to explain how the conducting network is formed in the polymer composite and also to explain the effect of other parameters like the interaction of filler and polymer, nature of fillers, the arrangement and concentration of fillers for enhancing the conductivity properties of the composite materials. In the present work different theoretical models like Scarisbrick and McCullough models are employed to predict the conductivity of PBMA nanocomposites containing different loadings of Nd₂O₃ nanoparticles.

Scarisbrick model

Scarisbrick assumed that the conductivity is accompanied by inter-particle contact within the polymer matrix and thus conductivity mainly depends on the amount as well as the arrangement of filler present in the matrix.³⁸ The Scarisbrick model can be expressed by the following equations.

\frac{σ c}{σ f} = C^{2} \cdot Φ \cdot Φ [exp (Φ^{- \frac{2}{3}})]

\frac{σ c}{σ f} = Φ \cdot Φ [exp (Φ^{- \frac{2}{3}})] (When C^{2} = 1)

\frac{σ c}{σ f} = 3 \times 10^{- 3} \cdot Φ \cdot Φ [exp (Φ^{- \frac{2}{3}})] (When C^{2} = 3 \times 10^{- 3})

where C² is the geometric factor, its value defines the dispersion mode of filler in the polymer matrix. The value of C² lies between 1 and 3 × 10⁻³. Here Φ is the filler volume fraction, σc and σf represent the DC conductivity of the composite and the filler respectively. The conductivity (σ_dc) of PBMA/Nd₂O₃ nanocomposites are calculated using the Scarisbrick model (equations (6) to (8)) and the comparative graph of theoretical and experimental σ_dc is given in Figure 9. From figure, it can be seen that the experimental conductivity is remarkably lower than the theoretical conductivity at the entire loading of Nd₂O₃ nanoparticles for both C² values. At lower filler loading, the theoretical conductivity value and experimental conductivity value shows large deviations compared to that at higher loading. The exact value of C² is difficult to find and also in this model the contribution from the polymer matrix is not considered. Therefore the theoretical conductivity using the Scarisbrick model exhibits large deviations from the experimentally determined conductivity for all composites, especially at lower concentrations.

Figure 9.

Theoretical and experimental plots of electrical conductivity based on Scarisbrick model.

McCullough model

McCullough proposed a model for predicting the transport properties of binary systems and it can also be used for calculating the conductivity polymer composites.³⁹ The equation is as follows.

σ c = σ p \cdot Φ p + σ \cdot Φ f - [\frac{λ \cdot Φ p \cdot Φ f + {(σ f - σ p)}^{2}}{v f \cdot σ f + v p \cdot σ p}]

where λ is the structural factor, indicating the extent of conductive network formation in the polymer matrix and its value can range from 0 to 1, νf and νp are given as

v f = (1 - λ) \cdot Φ f + Φ p \cdot λ

v p = (1 - λ) \cdot Φ p + Φ f \cdot λ

The theoretical conductivity of PBMA/Nd₂O₃ nanocomposites is determined from the McCullough model (equations (9) to (11)) for different λ values and the comparative graph of theoretical and experimental conductivity is presented in Figure 10. The theoretical conductivity using the McCullough model greatly depends on the λ values which in turn depends on filler properties and so the exact theoretical value of λ is not known. In order to validate the McCullough model the conductivity is calculated for various λ values. Interestingly, in the of PBMA/Nd₂O₃ nanocomposites, the experimental conductivity shows large deviations from that of the theoretical conductivities. So McCullough model also fails in the case of PBMA/Nd₂O₃ nanocomposites.

Figure 10.

Theoretical and experimental conductivity based on McCullough model.

Proposed model for PBMA/Nd₂O₃ composites

The electrical conductivity determined from Scarisbrick and McCullough model failed to explain the conductivity of PBMA/Nd₂O₃ composites because of the difference in conductivity of pure polymer and the nanoparticles. The mismatch between theoretical and experimental conductivity can be overcome by considering the factors affecting the composite properties such as geometry, morphology, aspect ratio, shape and size. Here we suggest a new model by considering the shape factor (S) of the composite system as:

log σ c = \frac{Φ p \cdot log σ p + Φ f \cdot S \cdot log σ f}{Φ p \cdot e^{Φ f} + Φ f \cdot S \cdot e^{Φ p}}

The experimental conductivity values are applied to the above proposed equation and the result is given in Figure 11. The resultant conductivity value from proposed model is in good agreement with the experimentally measured values. This finding has been considered encouraging for developing new and innovative thermoplastic composite materials for using augmented tensile strength and nano-electronics devices.

Figure 11.

Theoretical and experimental conductivity based on proposed model.

Conclusions

Poly (butyl methacrylate) nanocomposites with enhanced dielectric constant and mechanical properties were developed by incorporating Nd₂O₃ nanoparticles via in situ polymerization method. The SEM images showed the homogenous dispersion of nanoparticles in the PBMA chain. The result from XRD revealed a systematic and ordered arrangement of Nd₂O₃ nanoparticles in the PBMA matrix. The tensile strength of PBMA composites was substantially enhanced with the interaction of nanoparticles, however, the elongation at break decreased with the addition of nanoparticles. The nanocomposite reinforced with 5 wt% Nd₂O₃ nanoparticles showed the highest mechanical strength compared with other percentage of filler loading. The experimental data of tensile strength was compared with different theoretical assumptions from Einstein, Mooney and Pukanszky models. Among the different theoretical assumptions, Pukanszky model was found to be in good agreement with the experimental tensile values indicating better interfacial interaction between the PBMA and Nd₂O₃ nanoparticles. The DC conductivity of PBMA was significantly improved with the addition of Nd₂O₃ nanoparticles. The experimental DC conductivity values were also correlated with the various theoretical assumptions by Scarisbrick and McCullough models. All these models fail to explain the conductivity of composite material and therefore we proposed a new model for theoretical conductivity which is well fitted with experimental conductivity.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was financially supported by KSCSTE, Government of Kerala, India (Order No. 566/2017/KSCSTE).

ORCID iD

MT Ramesan

References

Prashantha

Rashmi

Lee

. Preparation and characterization of carbon nanotube filled poly (2-hydroxyethylmethacrylate) nanocomposites. High Perform Polym 2012; 25: 97–103.

Bashir

Shakoor

Ahmed

, et al. Polypyrrole-Fe₂O₃ nanocomposites with high dielectric constant: in situ chemical polymerization. Polym Polym Compos 2018; 26: 233–241.

Shakoor

Rizvi

Foot

PJS

. Synthesis and characterisation of polyaniline/montmorillonite nanocomposites. Polym Polym Compos 2009; 17: 359–363.

Suhailath

Ramesan

. Effect of neodymium-doped titanium dioxide nanoparticles on the structural, mechanical, and electrical properties of poly (butyl methacrylate) nanocomposites. J Vinyl Addit Technol 2018; 25: 9–18.

Benabid

Khrachi

Zouai

, et al. Impact of co-mixing technique and surface modification of ZnO nanoparticles using stearic acid on their dispersion into HDPE to produce HDPE/ZnO nanocomposites. Polym Polym Compos 2019; 27: 389–399.

Martínez

Onofrio

González

. Mossbauer study of a Fe₃O₄/PMMA nanocomposite synthesized by sonochemistry. Hyperfine Interact 2013; 224: 99–107.

Ramesan

Nushhat

Parvathi

, et al. Nickel oxide @ polyindole/phenothiazine blend nanocomposites: preparation, characterization, thermal, electrical properties and gas sensing applications. J Mater Sci Mater Electron 2019; 30: 13719–13728.

Wang

Chang

Bian

, et al. Study on the preparation of graphene oxide/silica/natural rubber latex composites by different process. Polym Polym Compos 2019; 27: 135–142.

Jiang

Shi

, et al. The modification mechanism and the effect of magnesium chloride on poly (vinyl alcohol) films. RSC Adv 2019; 9: 1602–1612.

10.

Demir

Koynov

Akbey

, et al. Optical properties of composites of PMMA and surface-modified zincite nanoparticles. Macromolecules 2007; 40: 1089–1100.

11.

Rajendran

Mahendran

Krishnaveni

. Effect of CeO₂ on conductivity of PMMA/PEO polymer blend electrolytes. J New Mater Electrochem Syst 2003; 6: 25–28.

12.

Tabanli

Bilir

Eryurek

. Optical properties and Judd–Ofelt analysis of Nd₂O₃ nanocrystals embedded in polymethyl methacrylate. J Rare Earths 2017; 36: 170–178.

13.

Zheng

Gao

, et al. The role of rare earth lanthanum oxide in polymeric matrix brake composites to replace copper. Polymers 2018; 10: 1027.

14.

Bazzi

Brenier

Perriat

, et al. Optical properties of neodymium oxides at the nanometer scale. J Lumin 2005; 113: 161–167.

15.

Suhailath

Ramesan

. Investigations on the structural, mechanical, thermal, and electrical properties of Ce-doped TiO₂/poly (n-butyl methacrylate) nanocomposites. J Therm Anal Calorim 2019; 135: 2159–2169.

16.

Kovanda

Jindová

Lang

, et al. Preparation of layered double hydroxides intercalated with organic anions and their application in LDH/poly(butyl methacrylate) nanocomposites. Appl Clay Sci 2010; 48: 260–270.

17.

Nihmath

Ramesan

. Synthesis, characterization, processability, mechanical properties, flame retardant and oil resistance of chlorinated acrylonitrile butadiene rubber. Polym Adv Technol 2018; 29: 2165–2173.

18.

Bueche

. Mullins effect and rubber-filler interaction. J Appl Polym Sci 1961; 5: 271–281.

19.

Milner

Bunget

Farha

, et al. Modeling tensile strength of materials processed by accumulative roll bonding. J Manuf Process 2013; 15: 219–226.

20.

Taherian

. Development of an equation to model electrical conductivity of polymer-based carbon nanocomposites. ECS J Solid State Sci Technol 2014; 3: 26–28.

21.

Tjong

RKY

. Electrical conductivity and dielectric response of poly (vinylidene fluoride)–graphite nanoplatelet composites. Synth Met 2010; 160: 1912–1919.

22.

Jasna

Priyanka

Mathew

Evaluation of spectral, thermal, flame retardant, dielectric, solvent diffusion and transport behavior of novel nanocomposite derived from chlorinated styrene butadiene rubber and manganous tungstate. Polym Compos 2018; 39: E1880–E1889.

23.

Latha

Prakash

Karuthapandian

. Facile fabrication of visible light-driven CeO₂/PMMA thin film photocatalyst for degradation of CR and MO dyes. Res Chem Intermed 2013; 39: 5223–5240.

24.

Yuvakkumar

Hong

. Nd₂O₃: novel synthesis and characterization. J Sol-Gel Sci Technol 2015; 73: 511–517.

25.

Bahuleyan

Induja

Ramesan

. Influence of titanium dioxide nanoparticles on the structural, thermal, electrical properties, and gas sensing behavior of polyaniline/phenothiazine blend nanocomposites. Polym Compos 2019; 40: 4816–4826.

26.

Suhailath

Ramesan

. Effect of nano Ce doped TiO₂ on AC conductivity and DC conductivity modeling studies of poly (n-butyl methacrylate). J Electron Mater 2018; 47: 6484–6493.

27.

Sannakki

Anita . Dielectric properties of PMMA and its composites with ZrO₂. Phys Procedia 2013; 49: 15–26.

28.

Sankar

Parvathi

Ramesan

. Structural characterization, electrical properties and gas sensing applications of polypyrrole/Cu-Al₂O₃ hybrid nanocomposites. High Perform Polym 2020; 32: 719–728.

29.

Suhailath

Ramesan

. Effect of ceria nanoparticles on mechanical properties, thermal and dielectric properties of poly (butyl methacrylate) nanocomposites. Polym Compos 2020; 41: 2344–2354.

30.

Ramesan

Surya

. Studies on electrical, thermal and corrosion behaviour of cashew tree gum grafted poly (acrylamide). Polym Renew Resources 2016; 7: 81–100.

31.

Nihmath

Ramesan

. Development of novel elastomeric blends derived from chlorinated nitrile rubber and chlorinated ethylene propylene diene rubber. Polym Test 2020; 89: 106728.

32.

Hemlata Maiti

. Mechanical, morphological, and thermal properties of nanotalc reinforced PA6/SEBS-g-MA composites. J Appl Polym Sci 2015; 132: 41381.

33.

Einstein

Fürth

. Investigations on the theory of the Brownian movement. Mineola: Dover Publications, 1956.

34.

Ahmed

Jones

. A review of particulate reinforcement theories for polymer composites. J Mater Sci 1990; 25: 4933–4942.

35.

Pukanszky

. Influence of interface interaction on the ultimate tensile properties of polymer composites. Composites 1990; 21: 255–262.

36.

Sohi

NJS

Bhadra

Khastgir

. The effect of different carbon fillers on the electrical conductivity of ethylene vinyl acetate copolymer-based composites and the applicability of different conductivity models. Carbon 2011; 49: 1349–1361.

37.

Wolf

Willert-Porada

. Electrically conductive LCP–carbon composite with low carbon content for bipolar plate application in polymer electrolyte membrane fuel cell. J Power Sources 2006; 153: 41–46.

38.

Scarisbrick

. Electrically conducting mixtures. J Phys D Appl Phys 1973; 6: 2098–2110.

39.

McCullough

. Generalized combining rules for predicting transport properties of composite materials. Compos Sci Technol 1985; 22: 3–21.

Studies on mechanical properties,dielectric behavior and DC conductivity of neodymium oxide/poly (butyl methacrylate) nanocomposites

Abstract

Keywords

Introduction

Experimental

Materials and methods

Synthesis of PBMA/Nd2O3 nanocomposites

Characterization

Results and discussion

Morphological studies

XRD analysis

Dielectric properties

Mechanical studies

Tensile modeling studies

Einstein model

Mooney model

Pukanszky model

DC conductivity studies

Theoretical modeling of DC conductivity

Scarisbrick model

McCullough model

Proposed model for PBMA/Nd2O3 composites

Conclusions

Footnotes

Declaration of conflicting interests

Funding

ORCID iD

References

Synthesis of PBMA/Nd₂O₃ nanocomposites

Proposed model for PBMA/Nd₂O₃ composites