Ceramic-polymer Composites Research Articles

Flexible dielectric spacer with tunable dielectric properties for metamaterial absorber application

The development of a flexible and robust metamaterial absorber is a great motivation for the new generation of microwave absorbers covering any conformal shape. Ceramic–polymer composites with variable dielectric constant within the microwave frequencies are proposed as a flexible middle dielectric spacer (MDS) layer to provide an additional degree of design freedom for metamaterial absorber applications. By varying the dielectric constant of the MDS layer, the resonance band of the metamaterial absorber can be tuned while retaining a low profile in addition to enhancing its electromagnetic performance for transverse magnetic (TM) polarized waves. To formulate these composites, tetragonal structured barium titanate (BaTiO3) powder is selected as an excellent candidate when mixed with elastomer polydimethylsiloxane (PDMS), resulting in high mechanical strength substrates. Experimentally, samples with a range of dielectric permittivity from 2.81 to 5.67 were obtained for a 0%–20% volume fill fraction of BaTiO3 in PDMS. The obtained dielectric permittivities are consistent with the Bruggeman effective medium theory. Utilizing an optimized composition (10% BaTiO3), resulting in = 4 substrate, an X-band flexible absorber is designed and fabricated to absorb more than 90% of incident electromagnetic waves within a frequency band of 8.16–12.12 GHz.

The effect of extrusion and injection molding on physical, chemical, and biological properties of PLLA/HAp whiskers composites

This paper deals with physical, chemical and biological properties of polymer-ceramic composites based on poly(l-lactide) (PLLA) with the addition of 10, 20 or 30 % (by weight) of hydroxyapatite (HAp) whiskers, produced by a combination of twin-screw extrusion and injection molding techniques. The materials obtained were tested for morphology (scanning electron microscopy), chemical composition (energy dispersive x-ray spectroscopy, infrared spectroscopy), processing properties (melt flow rates and density), thermal properties (differential scanning calorimetry, thermogravimetry), strength (static tensile test, impact strength) and surface properties (optical profilometry, contact angle measurements). The biological evaluation was performed by in vitro assessment of the manufactured materials’ cytotoxicity, level of colonization by osteo- and fibroblasts and level of adhesion displayed by a microbial pathogen, referred to as the Staphylococcus aureus. The results indicate an influence of the applied processing path on the properties of the filler particles − the apatite whiskers were significantly shortened. On the other hand, we have demonstrated the possibility of obtaining PLLA/HAp composites with good strength parameters, precise geometric shape and slightly improved surface properties. The results of biological evaluation revealed that all of the materials obtained displayed low cytotoxicity and a high level of colonization, irrespective of the content of hydroxyapatite. The only exception was the composite containing 10 % HAp, for which we observed weaker fibroblast adhesion compared to other materials. In turn, the level of colonization by S.aureus grew with the increase in HAp content in polymers. Results of biological evaluation indicate that although obtained polymers display favorable properties in terms of eukaryotic cell adhesion/colonization, they may also provide advantageous surface conditions for bacterial development. Therefore, inclusion of antimicrobial to the materials obtained may be necessary and should be further investigated. Nevertheless, the results obtained certainly provide useful information from the point of view of designing and manufacturing of biocomposites for bone tissue engineering applications.

Enhancing Neural Stem Cell Stimulation with Structured Piezoelectric Composites: An In Vitro Study

Spinal cord injuries can cause permanent tissue damage with debilitating and lasting effects on patients. Electrical stimulation has been established as an effective approach for promoting neural regeneration. However, the clinical applicability of these techniques is limited by the necessity for wired connections and external power supplies, which increases risk of infection. Piezoelectric materials have the inherent ability to form electric surface potentials when subjected to a mechanical stress and can provide wireless electrical stimulation. However, current materials are not optimized for neurological applications as they are mechanically mismatched with neural tissue, and have poor biocompatibility. Further, reproducible systems for optimizing material design and stimulation paradigms have yet to be established. Here a new, advanced fabrication process to produce scalable, tuneable piezoelectric ceramic–polymer composites based on [K0.5Na0.5]NbO3 and polydimethylsiloxane is provided. It is demonstrated that these composites can be successfully utilized for the growth of neural stem cells, which are shown to survive, proliferate, retain stemness, and differentiate into their daughter populations. Neuronal differentiation appears to be preferred on poled substrates, in comparison to glass coverslips and unpoled substrates. It is shown that the composites can autonomously generate surface potentials, which opens new possibilities to study piezoelectrically induced electrical stimulation.

Giant flexoelectric response of uniformly dispersed BT-PVDF composite films induced by SDS-assisted treatment

Polymer-ceramic composites are commonly used as flexoelectric films. In existing studies, the flexoelectric effect of composites are generally improved by adjusting the material structures or adding ferroelectric materials. Further improvement of flexoelectric response has encountered a bottleneck. Considering from a new perspective, this study innovatively proposes to prepare the uniformly dispersed BT-PVDF composite films with giant flexoelectric response by surfactant SDS-assisted treatment. According tothe engineering applications, tilt sensors have been fabricated with the SDS/BT-PVDF composite films. The prepared tilt sensors can accurately sense the tilt change in a small-angle range (0-10°) between the coaxial connecting parts, the response signal changes significantly (49.25-72.35mV/°), and the response speed can reach 0.166 s. The research provides a new idea for improving the flexoelectric response and also paves a way for developing tilt sensors through a low-cost, facile, and reliable method, showing potential applications including bending sensing and structural health monitoring.

Study of frequency dependence properties of CCTO-BT/polymer composites

In the current study, the calcium copper titanate (CCTO)/polymer, barium titanate (BT)/polymer, and CCTO-BT/polymer composites with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression molding processes. The composites are characterized for the frequency dependence on dielectric properties, conductivity, impedance spectroscopy, and electrical modulus. X-ray diffraction (XRD) patterns of CCTO-BT/polymer composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric properties of hybrid CCTO-BT/polymer composites with 10 vol% CCTO 10 vol% BT, 12 vol% CCTO 8 vol% BT, and 8 vol% CCTO 12 vol% BT was found relatively better than those of the single ceramic filler reinforced polymer composites. AC conductivity analysis shows a significant improvement in the results of hybrid filler-filled CCTO-BT/polymer composites in comparison with single filler-filled polymer composites. Thus, impedance analysis confirms higher insulating properties for 8 vol% CCTO 12 vol% BT and 12 vol% CCTO 8 vol% BT hybrid CCTO-BT/polymer composites with respect to the single and other hybrid ceramic polymer composites. The analysis suggests the hybrid CCTO-BT/polymer composites to be adopted as a possible dielectric material for energy storage devices and other electronic applications.

Polymer-ceramic composites for bone challenging applications: Materials and manufacturing processes

The continuous advancement of bone restoration technologies is crucial for the creation of innovative materials that possess enhanced functional and technological capabilities. One promising area of research focuses on the development of composite materials combining polymers and ceramics for bone regeneration. These materials offer several advantages over traditional bone grafting materials, including the ability to be customized to meet the specific needs of individual patients and a reduced risk of disease transmission. In recent years, significant progress has been made in the development of polymer-ceramic biomaterials with improved capacities for bone regeneration. This progress has primarily concentrated on enhancing mechanical properties, biodegradability, and biocompatibility. The objective of this overview is to present the latest advancements in composite ceramic polymers used for bone regeneration, encompassing the corresponding manufacturing processes as well as the materials employed in these biomaterials.

Physicochemical and biological analysis of composite biomaterials containing hydroxyapatite for biological applications.

Bone tissue regeneration is one of the main areas of tissue engineering. A particularly important aspect is the development of new innovative composite materials intended for bone tissue engineering and/or bone substitution. In this article, the synthesis and characterization of ceramic-polymer composites based on polyvinylpyrrolidone, poly(vinyl alcohol) and hydroxyapatite (HAp) have been presented. The first part of the work deals with the synthesis and characterization of the ceramic phase. It was demonstrated that the obtained calcium phosphate is characterized by a heterogeneity and porosity indicating simultaneously its large specific surface area. Additionally, in the wound healing test, it was shown that the obtained powder supports the regeneration of L929 cells. Next, HAp-containing composite materials were obtained in the waste-free photopolymerization process and characterized in detail. It was proved that the obtained composites were characterized by sorption properties and stability during 12-day incubation in simulated physiological liquids. Importantly, the obtained composites showed no cytotoxic effect against the L929 murine fibroblasts - the cell viability was 94.5%. Then, confocal microscopy allowed to observe that murine fibroblasts effectively colonized the surface of the obtained polymer-ceramic composites, covering the entire surface of the biomaterial. Thus, the obtained results confirm the high potential of the obtained composites in the application of bone tissue regenerative medicine.

SH-wave scattering by the interface crack of piezoelectric ceramic polymer composites

The scattering of SH waves by interfacial crack in piezoelectric ceramic polymer composites is investigated. The mixed boundary condition are reduced to dual integral equations using Fourier transforms, and the series and Schmidt methods are used to solve an unknown quantity in crack displacement, and the expression of stress intensity factor at crack tip is obtained. The method was verified by degrading the piezoelectric ceramic polymer to the piezoelectric ceramic material. Finally, the crack propagation under different conditions such as frequency and angle are analyzed, as well as the influence of different piezoelectric ceramic polymer materials on crack propagation. It is of great significance for fracture propagation. This method can also be used as a guide for SH wave scattering of different interface cracks in real life, such as multi-cracks, rectangular crack and penny-shaped crack, so it can also be used as a starting point for future research.

Bioinspired ceramic-polymer composites with hierarchical nacre-mimetic structure via accumulative rolling technique

Constructing nacre-mimetic architecture in ceramic-polymer composites is an effective approach to improve fracture toughness. Here, ceramic-polymer composites with nacre-mimetic brick-and-mortar structure were fabricated using an accumulative rolling technique. Non-isometric and flaky Ti3AlC2 powders with ultrafine dimensions along with Al2O3 and h-BN powders with micron-sized dimensions were employed as constituents and the effect of their size on mechanical properties was investigated. The results showed that the flaky ceramic powders were preferentially aligned along the rolling direction under the shear force exerted by the rollers, and formed staggered stacking layers. Significant differences in the characteristic dimensions of flaky ceramic powders contributed to a hierarchical structure of the composites. Compared with the composites containing merely ultrafine-sized Ti3AlC2 flakes, the strength of composites decreased when Ti3AlC2 flakes were replaced by larger Al2O3 and h-BN flakes. However, such substitution inhibited the crack propagation, leading to a stable crack growth behavior featured by rising R-curves owing to the activation of various extrinsic toughening mechanisms, including crack deflection, uncracked-ligament bridging and pull-out of ceramic platelets. The accumulative rolling technique offers a simple but effective means for toughening ceramic materials and optimizing their functional properties along specific directions.

Dominant role of ceramic connectivity in microwave dielectric properties of porous ceramics

The connectivity of constituting phases plays an important role in the physical properties of composites and porous materials, while it is still overlooked in many cases. In the present work, CaTiO3 is used as the model material to clarify the effect of ceramic connectivity on the microwave dielectric properties of porous ceramics. CaTiO3-A and CaTiO3-B porous ceramics are prepared by partial sintering at 700–1200 °C and sintering at the optimum temperature of 1350 °C with the aid of porogen, respectively. With increasing the sintering temperature from 700 to 1000 °C, the relative density of CaTiO3-A ceramics maintains around 58%, while their εr, Qf, and τf increase dramatically (20.4–48.2, 968–4,237 GHz, and 443.9–724.2 ppm/ °C). The three parameters are even higher in CaTiO3-B ceramic with a similar relative density of 54.1% (69.1, 5,658 GHz, and 782.9 ppm/ °C). The huge variation in microwave dielectric properties is attributed to the significantly improved ceramic connectivity with sintering temperature observed from microstructure analysis. Finite element analysis further reveals that the ceramic connectivity plays the dominant role in the microwave dielectric properties by deciding the electric field distribution in CaTiO3 phase and pores and hence their contribution to dielectric response. The exponent α in exponential dielectric mixing rule is employed to describe the ceramic connectivity, and the trinary relationship among the microwave dielectric properties, constitution, and microstructure of porous ceramics is well constructed. This relationship can be extended to ceramic-polymer and ceramic-ceramic composites, which brings new perspectives for designing such microwave dielectric materials.

Preface

This Proceedings contains the selected papers of the 2023 3rd International Conference on Energy Engineering, New Energy Materials and Devices (NEMD 2023), which was held via virtual form in Guangzhou, China from March 24th to 26th, 2023.NEMD 2023 is aimed at the academic and scientific community and the productive sectors of the region, with the aim of disseminating academic and research work; moreover, promotes the exchange of experiences between researchers as well as the participation of the productive sectors in research, extension, technological development, and innovation activities, contributing to the strengthening the relationship between universities, enterprises and institutions.This Conference was articulated with different topics around the themes of Energy Engineering, New Energy Materials and Devices to discuss on the research findings, their possibilities and challenges. The relevance of the NEMD 2023 conference theme to a wide range of disciplines is reflected in the papers that have been submitted for publication. The topics covered in the Proceedings includes: Solar Photovoltaic Power Generation System, Principle and Technology of Solar Cell, Distributed Energy System Technology, Energy Conversion and Application, Green Energy Materials, etc.. All the papers, being reviewed through a double-blind review process, are original contributions to the topics and shown the research works that are doing in the field of the described theme.We had about 60 participants all around the world. The scientific program of the Conference was composed of keynote speech, oral presentation, and academic investigation. Assoc. Prof. Jing Guo from Xi’an Jiaotong University, China, who has published more than 80 academic publications, over 4600 SCI citations, with an H-factor of 40 (Google Academic), made a keynote speech on Ceramic-Polymer Composites Prepared via Cold Sintering Process. Ceramicpolymer composites have attracted much attention due to the excellent combined physical and chemical properties. However, most of the ceramics are sintered at high temperatures, typically higher than 1000 °C, which are not compatible with the processing temperatures of polymers. Thus, it is challenging to integrate ceramics with polymers in a onestep sintering process. Cold sintering process proposed in 2016 provides a route for the densification of ceramics at temperatures lower than 350 °C. He discussed the recent development of cold sintered electronic materials based on ceramic-polymer composites. The brilliant speeches of each speaker provided a feast of knowledge for all the participants, allowing them to communicate with each other and get some academic advice or suggestion.Our sincere thanks and gratitude to all the participants for making such a comprehensive NEMD Conference and Proceedings, which contribute to the enhancement and development in related fields. We are grateful to the Technical Program Committee for their valuable time and advice. Special thanks to the members of the Journal of Physics: Conference Series for making this Proceedings published. We appreciate the effort from those involved and look forward to a more successful conference next year.The Committee of NEMD 2023Committee Member are available in the pdf

Thermal and mechanical energy harvester based on flexible PVDF/PLZT polymer-ceramic composites

Thermal and mechanical energy harvester based on flexible PVDF/PLZT polymer-ceramic composites

High dielectric Al2O3-(20–30 wt%) HDPE composites processed via cold sintering

In the present work, the dielectric properties of cold sintered alumina (Al2O3) reinforced with 20–30 wt% HDPE composite was investigated. The Al2O3-HDPE composites were successfully processed via cold sintering at extremely low temperature in the range of 80–120 °C for 120 min with the application of uniaxial pressure of 500 MPa under vacuum. In fact, cold sintering is a promising method to consolidate ceramic-polymer composites with very large difference in melting points and other thermo-physical/chemical properties. In the present work, high dielectric constant (ε’) of 11.73 and low dielectric loss (tanδ) of 0.0076 measured for Cold Sintering Processed (CSPed) Al2O3-20HDPE and a little low ε’ of 9.13 and low tanδ of 0.0066 was evident for CSPed-Al2O3-30HDPE at 1 MHz. Such differences in the dielectric properties of the Al2O3-20,30 HDPE composites depend on the crystallite size, dangling bond density and microstrain of the materials. Increase in ε’ with temperature is noticed for CSPed-A20H. Moreover, for CSPed-A20H at 1 MHz the temperature variation of dielectric constant (TCC) of 186.94 ppm/°C (or 0.018694 %/°C) was estimated and it reflects a marginal variation of ε’ with temperature. The coefficient of thermal expansion (CTE) of 87.25 × 10−6 °C−1 and 109.3 × 10−6 °C−1 was estimated for CSPed-A20H and CSPed-A30H, respectively. Overall, the cold sintered Al2O3-20HDPE composites exhibited comparable or better dielectric properties than Al2O3 based materials (as reported in the literature) processed by conventional sintering or cold sintering processes.

Improved coefficient thermal expansion and mechanical properties of PTFE composites for high-frequency communication

With the combined advantages of polymers and ceramic fillers, Polymer-ceramic dielectric composites are widely used in microwave substrates due to their excellent dielectric properties, good mechanical properties, and easy formability. To optimize the properties of polymer composites, it is necessary to enhance the compatibility between polymer matrix and ceramic filler. In this study, to realize polytetrafluoroethylene (PTFE) composites with low dielectric constant, low dielectric loss, good mechanical properties and appropriate coefficient of thermal expansion, PTFE/SiO2 composites were prepared by demulsification treated PTFE and modifying SiO2 with silane treatment. Compared with PTFE composites, the mechanical properties of PTFE/SiO2 composites prepared by the demulsification treatment were improved at a low SiO2 content. Compared with the untreated PTFE composites, treated PTFE composites exhibit better properties such as lower dielectric loss, good mechanical properties and lower CTE. Furthermore, the composites show low dielectric constant and loss even at frequencies up to 10 GHz.

Cycling of block copolymer composites with lithium-conducting ceramic nanoparticles.

Solid polymer and perovskite-type ceramic electrolytes have both shown promise in advancing solid-state lithium metal batteries. Despite their favorable interfacial stability against lithium metal, polymer electrolytes face issues due to their low ionic conductivity and poor mechanical strength. Highly conductive and mechanically robust ceramics, on the other hand, cannot physically remain in contact with redox-active particles that expand and contract during charge-discharge cycles unless excessive pressures are used. To overcome the disadvantages of each material, polymer-ceramic composites can be formed; however, depletion interactions will always lead to aggregation of the ceramic particles if a homopolymer above its melting temperature is used. In this study, we incorporate Li0.33La0.56TiO3 (LLTO) nanoparticles into a block copolymer, polystyrene-b-poly (ethylene oxide) (SEO), to develop a polymer-composite electrolyte (SEO-LLTO). TEMs of the same nanoparticles in polyethylene oxide (PEO) show highly aggregated particles whereas a significant fraction of the nanoparticles are dispersed within the PEO-rich lamellae of the SEO-LLTO electrolyte. We use synchrotron hard x-ray microtomography to study the cell failure and interfacial stability of SEO-LLTO in cycled lithium-lithium symmetric cells. Three-dimensional tomograms reveal the formation of large globular lithium structures in the vicinity of the LLTO aggregates. Encasing the SEO-LLTO between layers of SEO to form a "sandwich" electrolyte, we prevent direct contact of LLTO with lithium metal, which allows for the passage of seven-fold higher current densities without signatures of lithium deposition around LLTO. We posit that eliminating particle clustering and direct contact of LLTO and lithium metal through dry processing techniques is crucial to enabling composite electrolytes.

Fabrication and testing of bioinspired microstructured alumina composites with sacrificial interpenetrating polymer bonds

Bioinspired composites exhibit well-defined microstructures, where anisotropic ceramic particles are assembled and bonded by an organic matrix. However, it is difficult to fabricate these composites where both the ceramic particles and organic matrix work together to unlock toughening mechanisms, such as shear dissipation, particle rotation and interlocking, etc, that lead to stiff, strong, and tough mechanical properties. Here, we produce composites inspired by seashells, made of alumina microplatelets assembled in complex microstructures and that are physically bonded by a small amount of interpenetrated polymer network (IPN) made of polyacrylamide (PAM) and poly-N-isopropylacrylamide (PNIPAM). The fabrication employs magnetically assisted slip-casting to orient the microplatelets as desired, and in situ gelation of the IPN, followed by drying. The process was successful after carefully tuning the slip casting and gelation kinetics. Samples with horizontal, vertical, and alternating vertical and horizontal microplatelets orientations were then tested under compression. It was found that the IPN threads bonding the microplatelets acted as sacrificial bonds dissipating energy during the compression. Paired with the alternating microstructure, the IPN significantly enhanced the compressive toughness of the composites by 205% as compared to the composites with horizontal or vertical orientation only, with less than 35% reduction on the stiffness. This study demonstrates that microstructure control and design combined with a flexible and tough matrix can effectively enhance the properties of bioinspired ceramic polymer composites.

Microstructure and mechanical properties of BT/PVTC composite ferroelectric thin films.

Ferroelectric ceramic polymer composites have become the preferred electrocaloric materials due to their light weight and high polarization strength. But the mechanical properties were desired to be improved. In this study, the polyvinylidene fluoride trifluoro ethylene chloride (PVTC) and barium titanate (BT) composites were prepared, and the microstructure and mechanical properties were investigated by molecular dynamics simulations and experiments. It was found that with the increase of BT ceramic content in the composites, the yield stress is significantly reduced, which can be reduced by 16.07%. By comparing with the experimental data, the agglomeration and stress mechanism of the composites were proposed. The microstructure of the composite was analyzed using radial distribution function, self-diffusion coefficient, and glass transition temperature. The agglomeration mechanism of the composite was revealed from the microscopic point of view, and the rationality of the agglomeration behavior was verified by experiments. The calculations were performed by Material Studio 2019 software and the COMPASS force field was adopted.

Improving the performance of flexible composites based on 3-3 interconnected skeletons for piezoelectric energy harvesting

With the rapid development of microelectronics and portable devices, flexible piezoelectric electricity generators (FPEGs) as self-powered devices have attracted extensive attention. Piezoelectric ceramic-polymer composites with good flexibility is the core component of FPEGs. Having high d33 and g33 values is also essential for power generation. Herein, the porous ceramic skeleton is prepared using PZT based as the ceramic powder and polyurethane sponge as the template, followed by compounding the porous ceramic skeleton with polydimethylsiloxane (PDMS) by vacuum impregnation to prepare a 3-3 interconnected composite. When the ratio of ceramic phase in the ceramic slurry is 75 wt%, the volume fraction of the ceramic phase in the composite can achieve 37 vol%. Before compounding PDMS, porous ceramics are polarised, which is called pre-polarisation. The d33 value of the pre-polarised composites can reach 158 pC/N as compared to not polarising the porous ceramic and then polarising it after composite; the improvement is 48%. In addition, the g33 value of the pre-polarized composites is up to 144 mV m/N. Moreover, the 3.0 × 1.2 × 0.2 cm3 FPEG can generate a maximum output voltage of 15 V and a maximum short circuit current of 167 nA at 9% compression strain. The maximum instantaneous power density is 990 nW/cm2, thereby providing a new idea for piezoelectric power generation.

Biomimetic Gradient Bouligand Structure Enhances Impact Resistance of Ceramic-Polymer Composites.

Biological materials relied on multiple synergistic structural design elements typically exhibit excellent comprehensive mechanical properties. Hierarchical incorporation of different biostructural elements into a single artificial material is a promising approach to enhance mechanical properties, but remains challenging. Herein, a biomimetic structural design strategy is proposed by coupling gradient structure with twisted plywood Bouligand structure, attempting to improve the impact resistance of ceramic-polymer composites. Via robocasting and sintering, kaolin ceramic filaments reinforced by coaxially aligned alumina nanoplatelets are arranged into Bouligand structure with a gradual transition in filament spacing along the thickness direction. After the following polymer infiltration, biomimetic ceramic-polymer composites with a gradient Bouligand (GB) structure are eventually fabricated. Experimental investigations reveal that the incorporation of gradient structure into Bouligand structure improves both the peak force and total energy absorption of the obtained ceramic-polymer composites. Computational modeling further suggests the substantial improvement in impact resistance by adopting GB structure, and clarifies the underlying deformation behavior of the biomimetic GB structured composites under impact. This biomimetic design strategy may provide valuable insights for developing lightweight and impact-resistant structural materials in the future.

Enabling high dielectric constant and low loss tangent in BaTiO3–epoxy composites through a 3D interconnected network structure of ceramic phase

Constructing ceramic–polymer composites with a 3–3 connectivity is an effective strategy to achieve a notable increase in the dielectric constant at low ceramic contents. However, the dielectric data of the 3–3 composites with a low ceramic content (<10 vol. %) are still limited, and further investigation is thus required. Herein, composites with a 3–3 connectivity, in which BaTiO3 (BTO) and epoxy are self-connected in three dimensions, were developed and constructed at low BTO contents (2.0–8.3 vol. %). A three-dimensional network structure of the BTO ceramic (3D-BTO) was constructed via the sacrificial template method using polyurethane foam as the template. The dielectric constant and loss tangent of the composites increased with increasing BTO content. At a BTO content of 8.3 vol. %, the dielectric constant of the composite considerably increased to 33.4 at 1 kHz, which was ∼10-fold higher than that of neat epoxy (3.5). The loss tangent had a low value of< 0.030. By comparing with several theoretical models, the dielectric constants of the composites were well fitted with the effective medium theory model at low fitting factors (n = 0.008–0.013). The considerable increase in the dielectric constant of the composites with a low loss tangent at a low BTO content was attributed to the strong interfacial polarization and continuous polarization pathways through the interconnected 3D-BTO network structure in the composites. This study fills the gap in the literature by providing missing data on the dielectric properties of 3–3 composites at low ceramic contents (<10 vol. %), as well as a theoretical prediction.