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Article

Development of Hybrid Titania/Polybenzoxazine Composite for Enhance Thermomechanical, Flame Retardancy and Dielectric Properties

by
Shakila Parveen Asrafali
†,
Thirukumaran Periyasamy
†,
Chaitany Jayprakash Raorane
,
Ramkumar Vanaraj
,
Vinit Raj
and
Seong-Cheol Kim
*
School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Sustainability 2023, 15(2), 1639; https://doi.org/10.3390/su15021639
Submission received: 18 November 2022 / Revised: 11 January 2023 / Accepted: 12 January 2023 / Published: 14 January 2023
Browse Figures
Versions Notes

Abstract

:
Polybenzoxazines (Pbzs) are a recently developed class of thermosetting polymeric materials possessing low surface free energy with nonfluorine or nonsilicon content. In the present study, a new type of Pbz-BN/TiO2 composite was fabricated using benzoxazine monomer bis(6-phenyl diazenyl-3-phenoxy-3,4-dihydro-2H-1,3-benzoxazinyl) benzonitrile and inorganic TiO2 fillers by a simple and inexpensive process. The thermal curing method was found to be effective for preparing superhydrophobic surfaces combining low surface energy and surface roughness. The presence of the benzonitrile group in the benzoxazine monomer paves the way for accelerating the curing of the benzoxazine monomer, as shown by the DSC analysis. The as-prepared Pbz/TiO2 surfaces containing 5 wt% of TiO2 generated a superhydrophobic surface exhibiting a static water contact angle (SWCA) of 146°. In addition, the effect of inorganic fillers on the thermal, mechanical and dielectric properties of the Pbz/TiO2 composites was investigated in detail.

1. Introduction

Polybenzoxazine (Pbz), a new class of thermosetting phenolic resins, has been developed to overcome the shortcomings of traditional phenolic resin while keeping the advantages of cost-effectiveness, heat resistance and flame retardancy. Benzoxazine-based thermosets exhibit high glass transition temperature and high modulus, even though they have relatively low cross-link densities owing to strong hydrogen bonding restricting segmental mobility and impeding network formation [1,2,3,4,5]. In spite of these, Pbz is considered a new class of low surface energy material and exhibits a large number of interesting properties, such as near-zero shrinkage during curing, high carbon content, low water absorption, high thermal stability, excellent electrical properties, etc. Low surface energy is important for many practical applications in coatings, self-cleaning materials and biomaterials [6,7,8,9].
Several studies have been conducted to improve the mechanical properties of polymers, such as strength, toughness and elastic modulus, among which the combination of nanoparticles (NPs) is one of the most current research topics. Since NPs are usually aggregated due to strong van der Waals forces, it is very difficult to achieve monodispersity in a resin matrix at the nanoscale. Agglomerated fillers not only suffer from the mechanical properties of the cured matrix, but also act as initiation points of cracks and fractures, which even deteriorate the mechanical properties. In other words, one of the critical issues is to achieve nonaggregated dispersion of the integrated NPs to impart the polymer matrix its remarkable mechanical, electrical and thermal properties. Their dispersion characteristics and interfacial adhesion can be improved by modifying the NP surface with suitable dispersants or polymer coating [9,10,11,12,13,14,15,16].
Modification of nanofillers with functional benzoxazine monomer (Bzo-BN) has proven to be a promising approach to prepare nanocomposites by exploiting the high flexibility of benzoxazine molecular design by synthesizing titania/polybenzoxazine nanocomposites via the thermal curing process. Transparent hybrid films were obtained, suggesting the dispersion of nanosized titania particles in a polybenzoxazine matrix. Novel polymer composites with nano-TiO2 content reinforced with polybenzoxazine were prepared. The adhesion between nano-TiO2 and Pbz-BN was found to be strong, and the distribution of nanofillers was relatively uniform; a novel benzoxazine with benzonitrile functionalization (Bzo-BN) was prepared and blended with TiO2 (with different ratios), leading to the formation of highly dispersible organic/inorganic polybenzoxazine/TiO2 hybrid composites [17,18,19,20,21,22,23,24].
The effect of dispersion of different wt% of TiO2 particles in benzoxazine was investigated by analyzing their polymer properties, viz., mechanical, thermal, water resistance and dielectric properties. TiO2 was used in this work, as it has a linear coefficient of thermal expansion closer to that of the polymer matrix and other excellent properties, such as high strength and surface toughness and excellent wear resistance. Although several studies on the effect of various dispersants on the mechanical behavior of polybenzoxazine nanocomposites have been reported previously, no studies based on benzoxazine/TiO2 matrices have been reported. Therefore, our preparation and evaluation procedure provides a good way to facilitate the dispersion of inorganic NPs with benzoxazine dispersants and to further improve the mechanical properties of benzoxazine/TiO2 composites.

2. Materials and Methods

2.1. Chemicals and Material

The materials, instrumentation methods, synthesis of precursors, i.e., 4-(phenyl diazenyl) phenol (PAP) and 4,4′ bis(4-aminophenoxy) benzonitrile (APBN) and structure analysis of these precursors are given in the Supplementary Materials.

2.2. Synthesis of Bis(6-Phenyl Diazenyl-3-Phenoxy-3,4-Dihydro-2H-1,3-Benzoxazinyl) Benzonitrile (Bzo-BN)

To start with, paraformaldehyde (1.8 g, 0.06 mol) was dissolved in DMSO (50 mL) at 100 °C. To the dissolved solution, the synthesized diamine (APBN, 3.2 g, 0.01 mol) and the phenol (PAP, 3.9 g, 0.02 mol) were added in parts, and the reaction mixture was further increased to 130 °C. After completion of reaction, the reaction mixture was allowed to reach room temperature, and the product precipitated in 1N NaOH solution. The collected precipitate was water washed to remove any unreactants, filtered and dried at 60 °C to afford brown powder of Bzo-BN monomer (Scheme 1) [25]. Yield: 82%.
FT-IR (KBr, cm−1): 936 (stretching vibrations of the oxazine ring), 1256 and 1045 (asymmetric and symmetric stretching vibrations of C-O-C), 1177 (stretching of C-N-C), 1340 (CH2 wagging), 2246 (-CN stretching vibrations), 1445 (trans N=N stretching vibrations); 1H-NMR (CDCl3, ppm): 5.4 (s, Ha, 4H), 4.6 (s, Hb, 4H) and 6.5–8.0 (m, aromatic protons); 13C-NMR CDCl3, ppm): 79 (O-CH2-N), 50 (Ar-CH2-N), 115 (-CN), 94 (Ar (C)-CN) and 110–155 (aromatic carbons).

2.3. Preparation of Pbz-BN/TiO2 Composites

Pbz-BN/TiO2 composites with varying ratios of TiO2 were prepared. Briefly, the synthesized Bzo monomer and TiO2 (1 wt% of Bzo-BN) were mixed with THF and stirred well to form a homogeneous solution. This solution was then poured onto a Petri dish, pretreated with dichlorodimethyl silane (for easy release of the cured film) and then cured, maintaining the temperature at 250 °C for 3 h. The cured films were then taken out with care. The Pbz/TiO2 composite thus prepared was denoted as Pbz-BN/T1. Similarly, other ratios of Pbz/TiO2 composites were denoted as Pbz-BN/T0, Pbz-BN/T3 and Pbz-BN/T5, respectively, with varying weight ratios of TiO2.

3. Results

3.1. Structural Analysis of Benzoxazine Monomer (Bzo-BN)

The FT-IR spectra of the synthesized benzoxazine monomer (Bzo-BN) are shown in Figure 1. It can be seen from the figure that the benzoxazine ring is characterized by the absorption bands at 936 cm−1, due to the stretching vibrations of the oxazine ring. Moreover, the benzoxazine ring also gives its characteristic absorption band at 1219 and 1021 cm−1 due to the asymmetric and symmetric stretching vibrations of the C-O-C bond and the C-N-C bond, respectively [26]. The nitrile (-CN) group shows its characteristic absorption bands at 2246 cm−1. Figure 2 illustrates the 1H-NMR and 13C-NMR spectra of the benzoxazine monomer (Bzo-BN). The oxazine ring protons [O-CH2-N (a) and Ar-CH2-N (b)] show two singlets at 5.4 and 4.6 ppm, respectively [25,27,28]. The aromatic ring protons are located between 6.5 and 8.0 ppm. The 13C-NMR spectrum shows the characteristic carbon resonances of Bzo-BN. The methylene carbons [O-CH2-N (a) and Ar-CH2-N (b)] of the oxazine ring resonate at 79 and 50 ppm, respectively. The carbon of the benzonitrile group resonates at 115 ppm, and the aromatic carbon attached to the benzonitrile group resonates at 94 ppm [29]. All other aromatic carbons resonate between 110 and 155 ppm, respectively.

3.2. Polymerization Behavior of Hybrids

DSC of the hybrids was performed to study the polymerization behavior of the benzoxazine monomer in the presence of TiO2 by monitoring the typical exothermic peak attributed to the ring-opening polymerization of benzoxazine (Bzo-BN) and its hybrids (Bzo-BN/T0-T5). The DSC curves in Figure 3 and values in Table 1 show that the neat benzoxazine monomer exhibits an exothermic curve with Tonset at 224 °C, Tmax at 243 °C and Tfinal at 256 °C. In comparison, for the hybrids, the exothermic curve shows that Tonset slightly shifted to a lower temperature (218 °C), and Tmax and Tfinal shifted to 251 and 262 °C, respectively. This result indicates that the ring-opening polymerization of the benzoxazine monomer has been accelerated by the presence of the nitrile group (acting as a catalyst) and thus lowers its onset of curing temperature. The addition of TiO2 particles into the Bzo monomer shifts the maximum and final curing temperature to a higher value, which could be due to the trapped TiO2 particles inside the monomer. Moreover, the ΔH value of Bzo-BN/TiO2 hybrids decreases with increasing TiO2 content. This is due to the fact that with increased TiO2 content, the Bzo content in the Bzo-BN/TiO2 hybrid decreased obviously, thus reducing their enthalpy values. A similar exothermic curing behavior was observed for bisphenol-A-based benzoxazine (BA-a)/inorganic nanofibers (30 wt%), where the maximum curing temperature of neat BA-a (240 °C) was shifted to 250 °C with the incorporation of the inorganic materials [30,31].

3.3. Morphology of PBz-BP/TiO2 Composites

Figure 4 shows the SEM micrographs of the Pbz-BN/TiO2 composites. The smooth surface of pure polybenzoxazine is clearly visible in the figure. As the titanium content increases (from 1 to 5% by weight), the surface of the composites loses its smoothness and becomes rough. It also shows the formation of homogeneous hybrid material and fine dispersion of titanium particles [32]. As the TiO2 content increases to 5% loading, few voids or gaps appear on the surface of the composites. AFM images (Figure 5) of polybenzoxazine and their composites show that the size of the nodules formed by the Pbz-TiO2 particles is uniform and has a uniform distribution, as seen in the SEM images. The surface roughness of polybenzoxazine-silica hybrids was calculated from AFM measurements using Equation (1) [33],
Rt = Rp + Rv
where Rt is the total roughness of the measured sample, Rp is the maximum peak height of the profile and Rv is the maximum valley depth of the profile. The total roughness was found to be 8, 83, 109 and 128 nm for Pbz-BP:T0, Pbz-BP:T1, Pbz-BP:T3 and Pbz-BP:T5, respectively. The roughness value increases with increasing titanium content from 1 to 5 wt%, which is consistent with the AFM images.

3.4. Surface Properties of the Polybenzoxazine-Titania Hybrids

As is known, superhydrophobic surfaces can be prepared by combining low surface area and free energy materials with rough structures. In this case, Pbzo-BN with a network of hydrogen bonds and nitrile structures was used as a low surface area and free energy material [34]. The addition of TiO2 NPs was able to form rough structures. Figure 6 shows the WCAs of neat polybenzoxazine and polybenzoxazine-titania hybrid (Pbz-BP:T1, Pbz-BP:T3 and Pbz-BP:T5) coatings with different mass ratios of TiO2 NPs. The pure Pbz coating showed hydrophobicity with a WCA of 87°. With the increase in the additional amount of TiO2 NPs, the hydrophobicity of the Pbz/TiO2 also increased significantly with a linear increase in WCA from 87 to 146 °C. The hydrophobicity of polybenzoxazine was improved by incorporating TiO2 nanoparticles even at low concentrations (e.g., 5 wt% TiO2). The increased hydrophobicity of the Pbz-BP:T5 hybrid is attributed to the air trapped in the voids of the rough surface and preventing water from entering the nanoparticles, leading to an increase in the contact angle with water [35].

3.5. Dynamic Mechanical Properties of Titanium-Modified Polybenzoxazine Hybrids

The dynamic mechanical properties of the hybrid materials in comparison to neat polybenzoxazine were examined. Figure 7 shows the storage modulus (E′) and loss modulus (E″) as a function of temperature. The storage modulus of the neat Pbz drops slowly to 125 °C, after which there is a sharp drop with a glass transition temperature (Tg) of 147 °C obtained from the maximum loss modulus. The storage moduli of the composites in the glassy state increase with the inclusion of titanium particles and rise more on further increasing the content of titanium in the hybrids [36,37,38]. This behavior indicates that the dispersed titanium nanoparticles are effective to reinforce the polybenzoxazine matrix. The drastic improvement of the storage modulus of polybenzoxazine by hybridization with a small amount of titanium nanoparticles (5%) can be attributed to the reinforcing role of the titanium nanoparticles and the increase in the polymerization degree of polybenzoxazine via their nitrile group on the ring-opening polymerization similar to the role of silica, clay and other inorganic nanomaterials on polybenzoxazine nanocomposites as previously reported [37,39]. In addition, the hybrids show higher Tg than the neat resin. The Tg of pure polybenzoxazine was found to be 147 °C, but for the composites, the Tg increased with increasing nanofiller content (Tg of Pbz-BP/T5 is 164 °C). The hard and rigid inorganic regions create an obstacle to the movements of random chain segments in the matrix. This restricted mobility of the segmental molecular chains results in increased Tg values. A similar increase in Tg values is observed in PBA-a composites with other inorganic nanofibers, ranging between 185 and 193 °C [40,41,42,43].

3.6. Cross-Link Density of Pbz/TiO2 Composites

The cross-link density (CLD), γc is the number of network chain molecules per unit volume of the cured polymer. The cross-linking density of highly cross-linked thermoset materials can be determined by modulus measurements using the modulus constitutive equation given below [44],
γc = ε’/3RT
where ɛ’ = storage tensile modulus (from DMA), and T = temperature in K corresponding to the value of the storage modulus, R = gas constant
Table 2 shows the interconnect density of the Pbz/TiO2 composites. The cross-linking density of the pure polymer, i.e., Pbz-BN/T0, was found to be 3.7 × 10−5 mol m−3, while the cross-linking density of the composite, i.e., Pbz-BN/T5, was found to be 4.3 × 10−5 mol m−3. It can be seen that the cross-linking density obviously increases with the increase in the nanoparticle content in the composites. The main reason is that the nanoparticles behave as natural cross-linkers by forming intermolecular hydrogen bonds between the hydroxyl groups of the nanoparticles and the -OH,-CN of the polybenzoxazine (s), thus limiting their molecular motion [2,45].

3.7. Thermal Stability of Pbz/TiO2 Composites

The thermal stability of the hybrids was studied by thermogravimetric analysis to investigate the effect of dispersed titanium particles on the thermal stability of the polybenzoxazine matrix. Figure 8 shows the TGA profiles under nitrogen atmosphere of pure Pbz and the composites containing various percentages of titanium. For pure Pbz, Ti, T5 and T10 are 286, 326 and 354 °C with a char yield of 42.6%. The incorporation of titanium particles in the Pbz matrix led to an increase in thermal stability. The initial 5% and 10% degradation was found to be 296, 351 and 374 °C for Pbz-BN/T1, 308, 364 and 386 °C for Pbz-BN/T3, and 313, 378 and 403 °C for Pbz-BN/T5. For example, the char yield increased from 42.6 to 46.4, 51.2 and 53.7% with the addition of 0, 1, 3 and 5 wt% titania, suggesting that the dispersed titanium particles in the matrix act as a thermal insulator to protect the Pbz matrix. In addition, the composites also contain a nitrile group, by which the thermal stability showed a greater improvement. This could be attributed to the maximized adhesion between the organic (Pbz) and inorganic (titanium) sites, which further protect the organic matrix with thermal insulation [46,47,48].

3.8. Flame Retardancy of Pbz/TiO2 Composites

The flammability resistance of pure Pbz and Pbz-TiO2 composites is explained as a function of the limiting oxygen index (LOI) value. One way to calculate the LOI is by TGA analysis, knowing their corresponding carbon yield values. Van Krevelen and Hofytzer used the equation [49] given below to calculate the LOI,
LOI = 17.5 + 0.4 × CY
where LOI is the oxygen limit index, and CY is the char yield (from TGA data).
The value of LOI for the pure Pbz-BN polymer was 34.5, and their composites showed LOI values of 36.1, 38.0 and 39.0 for Pbz-BN/T1, Pbz-BN/T3 and Pbz-BN/T5, respectively (Table 3). It could be observed that the LOI value of polybenzoxazine and its composites was higher than the threshold value (26). This clearly indicates that the incorporation of TiO2 nanoparticles in the Pbz system results in thermosets with good self-extinguishing and flame-retardant properties.

3.9. Dielectric Properties of Pbz/TiO2 Composites

Dielectric materials can be used to store electrical energy in the form of charge separation when the electron distributions around their constituent atoms or molecules are polarized by an external electric field. The dielectric constant is directly related to the polarizability of the material and is therefore highly dependent on its chemical structure. Figure 9 shows the values of the dielectric constant and the dielectric loss of Pbz/TiO2 composites. The values of dielectric constant and dielectric loss were found to be in the range of 3.2–2.9 and 0.94–0.78 for Pbz-BN/TiO2 composites, respectively (Table 4). Composites differ from microcomposites in three aspects: they contain small amounts of fillers, the filler particles have sizes in the order of nanometers and the interface between the filler and the polymer is large. Nanoparticles reduce the movement of the polymer chain by physical bonding [50]. The mobility of the charge carriers also decreased with particle loading, suggesting that the nanoparticles disperse the carriers by reducing their mobility, leading to a decrease in permeability with increasing frequency [33].

4. Conclusions

In this study, a novel benzoxazine monomer (Bzo-BN) containing benzonitrile moiety was synthesized using a simple Mannich condensation reaction. Titania particles (with varying contents) were directly mixed with the Bzo monomer and thermally cured by undergoing self-polymerization to produce Pbz/TiO2 composites. The curing behavior of the Bzo monomer and their hybrids with TiO2 has been highly accelerated by the presence of the benzonitrile group. A sharp increase in the contact angle for the composite Pbz-BN/T5 (146°) was observed even with a very small amount of titania loading (~ 5 wt%). In spite of this, a drastic improvement in thermal, i.e., T5 = 378 °C and T10 = 403 °C, mechanical, i.e., E’ = 3.26 GPa, and dielectric, i.e., ε’ = 2.9, properties was obtained for Pbz-BN/T5. These improvements are due to the difference in surface energies between Pbz and inorganic fillers that generated surfaces with various roughnesses causing important amelioration in the thermomechanical and dielectric properties of the neat Pbz resin. This type of conventional processing enables the use of low-cost fabrication processes and provides flexibility for designing superhydrophobic surfaces that have enough potential to be utilized in a wide range of practical applications.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/su15021639/s1, Scheme S1: Synthesis of 4-phenyl diazenyl phenol (PAP); Scheme S2: Synthesis of bis(4,4’-aminophenoxy)benzophenone (APBP); Figure S1: FT-IR spectrum of PAP; Figure S2: 1H-and 13C-NMR of PAP; Figure S3: FT-IR spectrum of APBN; Figure S4: 1H-and 13C-NMR spectra of APBN.

Author Contributions

Conceptualization, S.P.A. and T.P.; Methodology, C.J.R.; Software, R.V.; Validation, V.R., S.P.A. and T.P.; Formal analysis, C.J.R.; Investigation, R.V.; Resources, V.R.; Data curation, S.P.A.; Writing—original draft preparation, S.P.A.; Writing—review and editing, S.P.A. and C.J.R.; Visualization, T.P.; Supervision, S.-C.K.; Project administration, S.-C.K.; Funding acquisition, S.-C.K. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2020R1I1A3052258). In addition, the work was also supported by the Technology Development Program (S3060516) funded by the Ministry of SMEs and Startups (MSS, Republic of Korea) in 2021.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

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Scheme 1. Synthesis of benzoxazine monomer (Bzo-BN).
Scheme 1. Synthesis of benzoxazine monomer (Bzo-BN).
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Figure 1. FT-IR spectrum of Bzo-BN.
Figure 1. FT-IR spectrum of Bzo-BN.
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Figure 2. 1H-NMR (A) and 13C-NMR (B) spectra of Bzo-BN.
Figure 2. 1H-NMR (A) and 13C-NMR (B) spectra of Bzo-BN.
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Figure 3. DSC thermograms of (a) Bzo-BN/T0, (b) Bzo-BN/T1, (c) Bzo-BN/T3 and (d) Bzo-BN/T5.
Figure 3. DSC thermograms of (a) Bzo-BN/T0, (b) Bzo-BN/T1, (c) Bzo-BN/T3 and (d) Bzo-BN/T5.
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Figure 4. SEM images of (a) Pbz-BN/T0, (b) Pbz-BN/T1, (c) Pbz-BN/T3 and (d) Pbz-BN/T5.
Figure 4. SEM images of (a) Pbz-BN/T0, (b) Pbz-BN/T1, (c) Pbz-BN/T3 and (d) Pbz-BN/T5.
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Figure 5. AFM images of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
Figure 5. AFM images of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
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Figure 6. Static WCA of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
Figure 6. Static WCA of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
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Figure 7. DMA analysis showing storage modulus (7A) and loss modulus (7B) of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
Figure 7. DMA analysis showing storage modulus (7A) and loss modulus (7B) of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
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Figure 8. TGA thermograms of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
Figure 8. TGA thermograms of (a) Pbz–BN/T0, (b) Pbz–BN/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
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Figure 9. Dielectric constant (9A) and dielectric loss (9B) of (a) Pbz–BN/T0, (b) Pbz–BP/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
Figure 9. Dielectric constant (9A) and dielectric loss (9B) of (a) Pbz–BN/T0, (b) Pbz–BP/T1, (c) Pbz–BN/T3 and (d) Pbz–BN/T5.
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Table
Table 1. Data from DSC thermograms of Bzo-BN/TiO2 hybrids.
Table 1. Data from DSC thermograms of Bzo-BN/TiO2 hybrids.
SampleTiO2 RatioT onset (°C)T max(°C)T final (°C)
Bzo-BN/TiO20224243256
1223245258
3220248261
5218251262
Table
Table 2. DMA data of Pbz–BN/TiO2 composites.
Table 2. DMA data of Pbz–BN/TiO2 composites.
SampleTiO2 RatioDMA
Storage ModulusTg (°C)CLD
* 105 mol/m3
PBz-BN/TiO202.811473.7
13.151514.1
33.211574.2
53.261644.3
Table
Table 3. TGA data of Pbz-BN/TiO2 composites.
Table 3. TGA data of Pbz-BN/TiO2 composites.
SampleTiO2 RatioTi (°C)T5 (°C)T10 (°C)CYLOI
PBz-BN/TiO2028632635442.634.5
129635137446.436.1
330836438651.238.0
531337840353.739.0
Table
Table 4. Dielectric data of Pbz-BN/TiO2 composites.
Table 4. Dielectric data of Pbz-BN/TiO2 composites.
SampleTiO2 RatioDielectric
ConstantLoss
PBz-BN/TiO203.20.94
13.10.93
33.00.87
52.90.78
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Asrafali, S.P.; Periyasamy, T.; Raorane, C.J.; Vanaraj, R.; Raj, V.; Kim, S.-C. Development of Hybrid Titania/Polybenzoxazine Composite for Enhance Thermomechanical, Flame Retardancy and Dielectric Properties. Sustainability 2023, 15, 1639. https://doi.org/10.3390/su15021639

AMA Style

Asrafali SP, Periyasamy T, Raorane CJ, Vanaraj R, Raj V, Kim S-C. Development of Hybrid Titania/Polybenzoxazine Composite for Enhance Thermomechanical, Flame Retardancy and Dielectric Properties. Sustainability. 2023; 15(2):1639. https://doi.org/10.3390/su15021639

Chicago/Turabian Style

Asrafali, Shakila Parveen, Thirukumaran Periyasamy, Chaitany Jayprakash Raorane, Ramkumar Vanaraj, Vinit Raj, and Seong-Cheol Kim. 2023. "Development of Hybrid Titania/Polybenzoxazine Composite for Enhance Thermomechanical, Flame Retardancy and Dielectric Properties" Sustainability 15, no. 2: 1639. https://doi.org/10.3390/su15021639

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