Introduction

MacDiarmid and coworkers discovered the significant features of conjugated polyacetylene to be a conducting polymer in the last century, notably in 1976, and how to enhance its ability over the full range from insulator to metal [1]. In general, conjugated polymers have been described as an alternating single (σ-bond) and double (π-bond) bonds along the carbon atoms on the alternating units[2] such as polyaniline [3, 4], polyacetylene [5, 6], polyfuran [7], polystyrene [8, 9], and Poly(vinyl carbazole) [10]. The hybridization of the carbon atom in the π-bond is sp2pz which overlap over the polymer skeleton, allowing the electron mobilization and charge transfer. Okutan et al. [11] studied the Impedance spectroscopy of polyaniline as a conductive polymer coated hydrogel. Ahlatcıoğlu [10] investigated the electro-optical properties of nanoclay/ poly(N-vinyl carbazole) nanoclay composites. Wang et al. [12] prepared polyolefin (COC)/polystyrene vitrimers (PSVMs) to reduce e-waste environmental contamination by using recycled printed circuit boards.

The conjugated polymer's diverse applications in various technologies have recently received a lot of attention due to their ability to combine the unique properties of conventional polymers such as low weight, good mechanical and flexibility with those of conventional semiconductors such as light emission and absorption, and tunable conductivity.Conjugated polymers, for example, have been used in a variety of critical applications, including electrods[13], solar cell [14, 15], optoelectronic devices [16,17,18], supercapacitor [19, 20], sensors [21, 22], smart fabrics [7, 23], transistors [24] and medical applications [25, 26].

Fluorination of the conjugated polymer skeleton has recently emerged as a promising method for improving the conjugated polymer's performance conductivity [27, 28]., fluorinated polymers are marked by high thermal resistance, besides their reactivity to different chemicals and good mechanical properties, which qualify them to be applied in membranes, coatings, and other applications [29,30,31].

On the other hand, Oxime is an organic group that belongs to imine with a general formula RR’C = N–OH with an organic side chain with hydrogen (R and R’). It is usually generated from carbonyl compounds with hydroxylamines via condensation. Also, oxime bonds are more stable than the corresponding hydrazone or imine at physiological pH, which is useful in biomedical applications [32]. Further, oxime is integrated in many industrial applications, such as Nylon 6 via synthesis of Caprolactam [33], as antidotes for nerve agents to treat organophosphorus poisonous [34], and commercial fragrances such as buccoxime and Stemone [35]. Also, owing to the properties of oxime bond formation, oxime chemistry is used for bioconjugation with only water as a side product [36, 37], and perillaldehyde is an artificial sweetener in Japan [38]. Oxime ligation has been utilized to functionalize polymers with micro and macromolecules of interest such as polycaprolactone [39], polyketoester [40], methacrylate [41], glycoproteins [42], bovine serum albumin, [43] vinyl levulinate [44]. As a matter of fact, oxime ester is less used in polymer applications. However recently, polyoxime ester has been used to enhance the performance of thermoset polymers [45, 46].

Styrene is a vital raw material in different industrial applications. Polystyrene sulfonate (PSS) has been widely used in a variety of applications over the last few decades, including electric devices as a hole transport material in polymer solar cells (PSCs) [15, 47], dye removal [48], polymer- stabilizer [49] and medical applications [50,51,52].

In this study, a new fluoro oxime ester ((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl) acetamide) (AIFPA) was synthesized by combining (E)-N-(4-fluorophenyl)-2-(hydroxyimino) acetamide with acrylic acid and polymerizing it via free radical polymerization (PAIFPA). Furthermore, the as-synthesized polymer has been incorporated into the grafting process with styrene sulfonate (PAIFPA-co-PSS). The chemical structures of fluoro oxime ester, PAIFPA, and PAIFPA-co-PSS were approved with FTIR and 1H NMR analysis. The molecular weight of both PAIFPA and PAIFPA-co-PSS was studied using 1H NMR analysis. Eventually, dielectric studies and optical properties have been explored for PAIFPA and PAIFPA-co-PSS.

Experimental and methods

Materials

4-fluoroaniline and chloral hydrate (Oxford Laboratory), sodium sulfate and hydroxylamine (Merc), benzoyl peroxide and polystyrene sod.sulfonate (Modern Lab chemicals, Egypt), chloroform (Sigma), HCl (Elnasr Co., Egypt).

Measurement techniques:

The 1H NMR spectra were performed using a Bruker Advance II 400 MHz spectrometer using deuterated dimethylsulfoxide as the solvent. The XRD has been performed via PANalytical X’Pert Pro with Cu-Kα radiation (λ = 0.154060 nm) at 30 kV and 30 mA. The patterns have been collected within the Bragg’s angle (2θ) ranging between 10° and 80°. FTIR-ATR spectral data was collected in the range of 4000–400 cm−1 using the spectrometer VERTEX 80 (Bruker Corporation, Germany). Ultraviolet–visible absorption spectra were measured using Jasco V-630 UV–VIS (Japan) in the wave length region of 200–1000 nm. Investigations on the samples dielectric properties were carried out at room temperature utilizing a Novocontrol high-resolution alpha analyzer over the frequency range of 10–1–107 Hz. In order to create a parallel-plate capacitor cell, the studied samples, each having a thickness that ranged from 1 to 2 mm, were sandwiched between two freshly polished brass electrodes that had a top electrode diameter of 10 mm like (Scheme 1). The complex permittivity, denoted by the equation ε* = ε′-iε′′, was determined by applying a sinusoidal voltage with an amplitude of 1 V to a frequency range covering 10–1–107 Hz. The examined composites can be characterized for complex dielectric spectroscopy by any of the complex parameters that are connected to each other by the equation that is presented below.

$${\varepsilon }^{*}\left(\omega \right)={\varepsilon^\prime}\left(\omega \right)-i{\varepsilon^{\prime\prime}}\left(\omega \right)=\frac{1}{{M}^{*}}=\frac{{\sigma }^{*}}{i\omega {\varepsilon }_{o}}$$
(1)

where M* is the complex dielectric modulus, σ* is the complex electric conductivity, ω is the angular frequency and εo is the vacuum permittivity (see Scheme 2).

Scheme 1
scheme 1

Schematic illustration of electrical measurement

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Scheme 2
scheme 2

(E)-N-(4-fluorophenyl)-2-(hydroxyimino)acetamide synthesis

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Methods

(E)-N-(4-fluorophenyl)-2-(hydroxyimino)acetamide synthesis

At 50 °C, 4-fluoroaniline (74 mmol, 4 mL) was dissolved dropwise (using a 1 mL syringe for addition) in 250 mL of 0.1 M HCl solution. Then hydroxylamine HCl (259 mmol, 9.5 g) followed by sodium sulfate (600 mmol, 42 g) were added. Chloral hydrate (88.8 mmol, 7.6 g) was dissolved in the solution, which was then stirred overnight at 50 ± 5 °C. The suspension was filtered and the filtrate discarded. The solid was washed with water and allowed to air dry for at least 24 h [53].

(E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl)acetamide synthesis (AIFPA)

1 mol of (E)-N-(4-fluorophenyl)-2-(hydroxyimino) acetamide was condensed with 1 mol of acrylic acid at 60 5 C for 2 h while stirring. Brownish sticky amidoester was obtained and confirmed using TLC, then measured qualitatively.

Poly((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl)acetamide) synthesis (PAIFPA)

PAIFPA was synthesized via free radical polymerization. Where, 0.2 g of benzoyl peroxide was added to a preweighed amount of AIFPA dissolved in 20 mL of DMF and refluxed at 80 ± 5 ◦C, stirring for 5 h. Eventually, the net product was washed several times with chloroform and dried in a vacuum furnace at 100 ◦C for 24 h.

Poly((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl)acetamide)-co-polystyrene sulfonate synthesis (PAIFPA-co-PSS)

In a round flask; 0.2 g of benzoyl peroxide (BPO) was added to a preweighed amount of PAIFPA dissolved in DMF, then 2 g of polystyrene sulfonate was added. The reaction vessel was allowed to reflux at 70 ± 5 ◦C for 5 h with stirring. The net product was washed several times with chloroform and dried in a vacuum furnace at 100 ◦C for 24 h (see Fig. 1).

Fig. 1
figure 1

ketoxime and aldoxime esters

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Results and discussion

Synthesis of AIFPA

Herein, AIFPA was synthesized by reacting (E)-N-(4-fluorophenyl)-2-(hydroxyimino)acetamide with acryloyl group as shown in Scheme 3. Acryloyl groups are an enaone form with acrylic groups as α,β–unsaturated carbonyl moiety with a C = C double bond at which electrophilic addition occurs, at C = O; nucleophilic addition and substitution occur. The carboxylic group reacts with alcohol, oxime, ammonia,..…etc. and it has a conjugated double bond [54]. Acrylic polymer is also used in nail polish [55], as capping agents [56], and as polymer electrolyte in dye-sensitized solar cells (DSSCs).

Scheme 3
scheme 3

(E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl)acetamide synthesis

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Scheme 3 represents AIFPA synthesis, where its chemical structure is recogenized by 1H NMR (Fig. 2a), which shows (DMSO-d6) δ/ppm: 7.98 (s, NH amide), 7.90 (s, CH aldimine), 7.18–7.51 (m, 4H benzene), 6.43 (s, H 1-ethylene trans), 6.62 (s, H 1-ethylene cis), 6.49 (s, H 1-ethylene gem); IR cm−1 (Fig. 2) shows ν: 3133 (C = CH alkene, stretch for sp2 carbon), 3013 (NH, stretch), 1764 (C = O, stretch), 1656 (-C = C- alkene, stretch), 1554 (NO, stretch), 1218 (C-O, ester, stretch), 989 (-CH bending R-CH = CH2), 805 (p-subst. benzene). The fragmentation pattern of AIFPA is illustrated in Scheme 5 where, MS m/z: 236 (50%).

Fig. 2
figure 2

1H NMR of: a AIFPA, b PAIFPA, and c PAIFPA-co-PSS

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Synthesis of PAIFPA and PAIFPA-co-PSS

Scheme 4 demonstrates the predictable polymerization route of PAIFPA and PAIFPA-co-PSS via free radical generation using BPO.

Scheme 4
scheme 4

Poly((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl)acetamide)-co-polystyrene sulfonate synthesis

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Scheme 5
scheme 5

fragmentation pattrern of AIFPA

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1HNMR assured the chemical structure of the resulting PAIFPA and PAIFPA-co-PSS. Where, Fig. 2b represents 1HNMR of PAIFPA (DMSO-d6) δ/ppm: 7.91 (s, NH amide), 7.66 (m, CH aldimine), 6.98–7.22 (m, 4H benzene), 6.78 (d, H 1-CC = O gem), 6.14 (d, H 1-CC = O cis), 2.95 (s, CH methine, 1 alpha –C = C), 2.82(s, CH methine, 1 alpha C), 2.42 (m, CH methine, 1 beta –C), 1.69 (m, CH2 methylene), 1.06 (s, CH3 methyl). On the other hand, Fig. 2c shows 1HNMR of PAIFPA-co-PSS (DMSO-d6) δ/ppm: 7.98 (s, NH amide), 7.81–7.95 (m, 4H benzene of PSS), 7.56(m, CH aldimine), 7.41–7.49 (m, 4H benzene of PAIFPA), 7.18 (m, 1 -NC(= O)), 5.82 (m, H 1-CC = O cis), 3.3 (m, CH methine, 1 beta -C), 3.09 (m, CH methine, 1 beta -C), 2.83 (d, CH methine, 1 alpha –C = C), 2.57 (m, CH methine, 1 alpha C), 2.69 (m, CH methine, 1 alpha –C(= O)), 1.94 (td, CH2 methylene), 1.23 (s, CH3 methyl) (see Fig. 2).

Moreover, 1HNMR is a promising application for identifying molecular weight as the areas under resonance peaks match with the molar concentration of the moieties in the analyzed sample [57]. Josephat U. Izunobi and Clement L. Higginbotham conducted a comparative study of the polymer number-average molecular weight (Mn) for (MPEG-NH2) and (MPEG-b-PLL(Z)) as model homopolymer and block copolymer, respectively using 1HNMR, GPC, and MALDI-TOFMS [58]. Mary L. Harrell and David E. Bergbreiter analyzed the number-average molecular weight of MPEG and its acetate derivative using 1HNMR.

The number of repeating unite (n) in each of PAIFPA, and PAIFPA-co-PSS has been calculated according to the following equation [58]

$${n}_{x= \frac{{a}_{x}{m}_{y}{n}_{y}}{{a}_{y}{m}_{x}}}$$
(2)

where ax is the area or intensity of the 1HNMR peak of moiety x; mx is the number of protons of moiety x; ay is the area or intensity of the 1HNMR peak of moiety y; ny is the number of repeating units of moiety y; and my is the number of protons of moiety y.

$${n}_{\mathrm{PAIFPA}= \frac{{{\varvec{a}}}_{CH}{{\varvec{m}}}_{CH3}{{\varvec{n}}}_{CH3}}{{{\varvec{a}}}_{CH3}{{\varvec{m}}}_{CH}}}$$
(3)

where aCH is the sum of CH integerals

$$=\frac{(314.05+11.69)\times 3\times 1}{55.02\times 1} =28.5\approx 29$$

Hence; \(\mathrm{Mn\;of\;PAIFPA}=235.19+\left(29\times 274\right)+237.21=8418.4\approx 8418\)

$${n}_{\mathrm{PAIFPA}-\mathrm{co}-\mathrm{PSS}= \frac{{{\varvec{a}}}_{CH}{{\varvec{m}}}_{CH3}{{\varvec{n}}}_{CH3}}{{{\varvec{a}}}_{CH3}{{\varvec{m}}}_{CH}}}$$
figure a

Where aCH is the sum of CH integerals in PSS moiety

$$=\frac{(546.17+35.3)\times 3\times 1}{8.84\times 1} =179.3\approx 179$$
figure b

Hence; \(\mathrm{MnofPAIFPA}-\mathrm{co}-\mathrm{PSS}=235.19+\left(29\times274\right)+\left(179\times193.18\right)+207.2=42967.1\approx42968\)

$$=42967.1\approx 42968$$

Figure 3 shows the ATR-FTIR of PAIFPA, and PAIFPA-co-PSS. For PAIFPA, the weak band at 3084 cm−1 is assigned to C = CH stretching vibration, while the band at 2985 cm−1 is refered to N–H stretching vibration. Tt 2960 cm−1 and 2935 cm−1, respectively asymmetric and symmetric stretching of CH2 is observed [59]. The band at 1409 cm−1 for the C-H bending alkane methyle group. The strong band at 1160 for C-O ester stretching vibration. The band at 1714 cm−1 and 1602 cm−1 is attributed to C = O and C = N, respectively [60, 61]. The stretching vibration of C = C–C aromatic ring is assigned at 1508 cm−1 [62]. A band of amide II is seen at 1546 cm−1 [63]. The weak band at 1438 cm−1 corresponds to aromatic C–C bonds and C-H wagging [62, 64]. The bending vibration of aliphatic CH in methylene group is shown at 1397 cm−1 [65]. The stretching vibration of C-F is observed at 1324 cm−1 [66]. The stretching vibration of C-O is seen at 1166 cm−1. The bending vibration of the monosubstituted alkene is presented at 989 cm−1.The band at 836 cm−1 is assigned to the plane of aromatic C-H. C-H and C-F out of plane bending vibration is related to bands at 519 cm−1 and 499 cm−1 [66].

Fig. 3
figure 3

ATR-FTIR of a AIFPA b PAIFPA, and c PAIFPA-co-PSS

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Bands at 1034 cm−1 and 1007 cm−1 correspond to asymmetric and symmetric stretching of S = O. A band at 670 cm−1, which was attributed to the SO−3 group, confirmed the presence of PSS in the complex [67, 68]. These data indicate that the polymer consists of the SO−3 group and the complexation between fluorobenzene and sulphonated polystyrene.

ketoxime and aldoxime esters were synthesized in a very simple method by Kumar et al. [69] at which oxime reacted with acid in presence of a catalyst at room temperature.

X-ray Diffraction (XRD)

Figure 4 represents the XRD of PAIFPA, and PAIFPA-co-PSS. In contrast to the reality of fluorine atoms being macromolecule chain polarity booster leading to enhancing the crystallite regions by increasing the intermolecular forces, causing a higher crystallinity, PAIFPA has a broad single diffraction peak at 2θ = 19.2° and virtually no crystal diffraction was witnessed. The observed amorphous diffraction may be induced because of the bulky fluorinated phenyl groups attached to the polymer skeleton, which generate looser chain packing and decrease the well-organized arrangement of the chain as well [70]. On the other hand, grafting PAIFPA with PSS enhances the crystallinity due to the existence of sulpher where a small peak is detected at 2θ = 7.1° [48, 49]. Moreover, the presence of sulfonate ions increases intermolecular forces as the peak at 2θ = 19.2°becomes less broad and their intensity increases, and there are additional peaks appearing at 2θ = 44.6° and 64.9° due to the electrostatic attraction between the negative charge of sulfonate ions and the positive charge generated on fluorine due to resonance as shown in Scheme 7. This means that the crystallinity increases and the interaction between PAIFPA and PSS.

Fig. 4
figure 4

XRD of (a) PAIFPA, and (b) PAIFPA-co-PSS

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The crystainaty indexs of both PAIFPA, and PAIFPA-co-PSS were calculated according to Eq. (1) [71]:

$$crystallinity index\% = \frac{Intergrated area of crystaine peaks}{Tota integerated area} \times 100$$
(4)

where, the crystallinity indexs of PAIFPA, and PAIFPA-co-PSS were 36.23 and 77.99%, respectevily.

Optical properties

Figure 5 shows the UV–Vis of PAIFPA, and PAIFPA-co-PSS. As seen in Fig. 5a, the two peaks, 208 nm and 232 nm, are assigned to n-π* and π-π* due to the presence of C = O, C = N, and C = C [72]. After the addition of PSS, the peaks at 208 nm and 232 nm are shifted to 204 nm and 226 nm (blue shift) ( Fig. 5b) [68], which is matched with the fact of the electrostatic interaction between both fluorobenzene and sulfonated polystyrene.

Fig. 5
figure 5

UV–Vis spectra of a PAIFPA, and b PAIFPA-co-PSS

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The value of information obtained from the absorption coefficient (α), such as the optical band gap energy and the electronic band structure, is important for investigating the optical properties of a material. The absorption coefficient (α) is related to absorbance (A) and thickness of sample (d) according to the following [73]:

$$\alpha (\uplambda )= \frac{2.303}{d} A$$
(5)

Figure 6 illustrates the relation between absorption coefficient (α) and photon energy (hʋ). The extrapolation of the linear portion of the curve with zero values of photon energy gives the values of the absorption edge. As seen, the value of the absorption edge of PAIFPA-co-PSS is lower than its value in PAIFPA. This means that the reaction between PAIFPA and PSS reorders the atoms of the PAIFPA-co-PSS and increases its crystallinity, as confirmed by XRD.

Fig. 6
figure 6

Relation between absorption coefficient (α) and hʋ of a PAIFPA, and b PAIFPA-co-PSS

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The optical transitions caused by photons of energy hʋ > Eg can be investigated using the following relationship for near edge optical absorption [73].

$$\alpha h\upsilon ={B(h\upsilon -{E}_{g})}^{n}$$
(6)

where B is constant, Eg is the band gap energy between valence and conduction band and n is called the power factor that characterize the optical transition. The power n takes value ½ for direct transition and 2 for indirect one.

The relation between (αhʋ)2 and (αhʋ)0.5 and hʋ for PAIFPA, and PAIFPA-co-PSS is depicted in Fig. 7. As seen, the values of direct and indirect band gap energy for PAIFPA are lower than those for copolymer. This means that the addition of PSS to PAIFPA changes their electronic structure. The reaction between PSS and PAIFPA increases the gap that separates the two localized states in PAIFPA-co-PSS and increase the potential barrier between them. As a result, the transfer of charge carriers between the localized states becomes difficult.

Fig. 7
figure 7

Relation between (αhʋ)1/2 and (αhʋ).2 versus hʋ for a PAIFPA, and b PAIFPA-co-PSS

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When photon energy hʋ < Eg, the absorption of photons is associated to the existence of localized tail states in the forbidden gap that related to the amorphous nature of material. The width of this tail is known as the Urbach tail that indicates the defect levels in the forbidden band gap and calculated using the following formula [74].

$$\alpha ={\alpha }_{0 }\mathrm{exp}\left(\frac{h\upsilon }{{E}_{u}}\right)$$
(7)

where α0 is a constant and Eu is the Urbach energy. Figure 8 illustrates the relation between ln α against hʋ. The relation give straight line whose the reciprocal of this slope give the value of Eu. Values of band tail energy for PAIFPA is greater than that for PAIFPA-co-PSS which affirmed that the crystallinity is increasing by interacting PAIFPA with PSS.

Fig. 8
figure 8

Relation between ln (α) versus (hʋ) for a PAIFPA, and b PAIFPA-co-PSS

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Dielectric properties

The electronic structure of π-conjugated polymers is generated from the hybridized wavefunction (sp2pz) of the carbon atom of the repeat unite. Semiconducting polymers are recognized to possess energy bands generated from the σ-band and σ*-band energy levels related to the σ-bonds between adjacent carbon atoms (sp2) which tighten the structure together and the pz wavefunctions associated with π-bond which endow unique properties of the conjugated polymers as semiconductors [75]. The obtained results show electrical conductivity values for PAIFPA ranging from 6.12 × 10–8 to 7.11 × 10–7 S.cm−1 at low and high frequency, respectively. Scheme 6 illustrates the possible charge mobilization among the PAIFPA macromolecule structure under an electric field. The expected electron conjugation occurs across fluorobenzene to the amide moiety. And as is well known, fluorine is an electron-donating group by resonance (+ M) creating a free electron radical cloud inside the benzene ring allowing reciprocal resonance in the benzene ring passing through the amide group which qualifies PAIFPA to be a p-type semiconducting polymer. On the other hand, contrary to expectations, electrical conductivity values of PAIFPA-co-PSS range from 5.48 × 10–10 to 7.75 × 10–8 S.cm−1 at low and high frequency, respectively, and this may back to the generated electrostatic attraction between fluorine and sulfonate ion leading to atom rearrangement and crystallinity increase as shown in XRD. In general and as is clear in Scheme 7, the sulfonate group is an electron- withdrawal group by resonance (–M) forming a hole (n-type) represented by a positive charge inside the benzene ring.

Scheme 6
scheme 6

Conjugation mechanism of PAIFPA

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Scheme 7
scheme 7

Conjugation mechanism of PAIFPA-co-PSS

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It is possible to determine a material's ability to store electrical charges by evaluating their dielectric measurement. Figure 9 represents the relation between the logarithm of dielectric constant (ε') and dielectric loss (ε") against the logarithm of frequency (log f) for PAIFPA, and PAIFPA-co-PSS. This is due to the ability of dipoles in samples to align themselves in the field direction, as well as charge accumulation between electrodes.By increasing the frequency, the charge is unable to follow the rapid change in the electric field and " decreases. At higher frequencies than 100 kHz, however, the dielectric constant remains constant and is frequency independent. However, when the frequency decreases, the dielectric constant ε'rises. Because of interfacial space-charging polarization, it can be concluded that using thin insulation barriers does not completely prevent the accumulation of ionic charge at metallic electrodes/insulating barriers/ionic sample interfaces, as shown by the increase in ε' observed on low frequency plateaus. A permanent dipole's alignment with the field and contribution to total polarization is complete at low frequencies [76]. As seen in Fig. 9, values of ε' and ε" for PAIFPA is higher than those for PAIFPA-co-PSS due to the addition of PSS restricting the motion of PAIFPA, so its values decrease [77].

Fig. 9
figure 9

Relation between log ε' and log ε" versus log f for a PAIFPA, and b PAIFPA-co-PSS

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The frequency dependence of conductivity is the summation of the amount of DC conductivity due to free charge movements and polarization conductivity due to bound charge movements. The increase in conductivity with frequency is popular for polymer and semiconductor materials. The first behaviour takes place when the frequency is independent of conductivity,which is contributed to by the free charges found in the material, and the second behaviour takes place when the frequency depends on the conductivity because of the trapped charge and it is only active in the high frequency region [78].

Figure 10 depicts the relationship between the logarithm of conductivity (log σ) as a function of the logarithm of frequency (log f). The increase in conductivity of all samples at high frequency because of the mobility of charge carriers is high in the high frequency field. As the frequency drops, more charge accumulates at the electrode–electrolyte interface, resulting in a reduction in the number of mobile ions and, finally, a decrease in conductivity at low frequencies [79].

Fig. 10
figure 10

Relation between log σ versus log f for a PAIFPA, and b PAIFPA-co-PSS

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The total conductivity, σ (ω) is the sum of dc and ac conductivity and is described using the following equation

$$\sigma \left(\omega \right)={\sigma }_{\text{dc}}\left(\omega \right)+\sigma {\text{ac}}\left(\omega \right)$$
(8)

As seen the conductivity of PAIFPA-co-PSS is lower than that for PAIFPA, and this attributed the decreasing of the mobility of free charge carrier and increasing the crystallinity of PAIFPA-co-PSS and this agreed with the results of XRD data and optical parameters.

Conclusion

The goal of this study is to create a novel poly((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl) acetamide) (PAIFPA) and its grafted structure with styrene sulfonate (PAIFPA-co-PSS). The chemical structure of the synthesized polymers was investigated by 1H NMR, FTIR, and XRD. The molecular weight of both PAIFPA, and PAIFPA-co-PSS was evaluated via 1H NMR analysis and found to be 8418, and 42,968, respectively. Further, the optical properties of PAIFPA, and PAIFPA-co-PSS was investigated where the absorbance was found to be in the blue shift and the bandgap was ranged from 2.6 eV to 3.5 Ev. and there is an increase in the band gap for PAIFPA-co-PSS is a short-wavelength light absorbers which can be used in tandem polymer solar cells. Eventually, the dielectric properties of PAIFPA and PAIFPA-co-PSS were performed, where PAIFPA-co-PSS shows electric conductivity values less than PAIFPA. This regarded to the generated electrostatic attraction between fluorine and sulfonate ion which leads to atoms rearrangement which results to increased crystallinity and this agreed to XRD.