Fiber-reinforced Composite Resin Research Articles

Mechanical Properties of Recycled Carbon Fiber-Reinforced Resin Composites 3D Printed via Digital Light Processing

Mechanical Properties of Recycled Carbon Fiber-Reinforced Resin Composites 3D Printed via Digital Light Processing

The distinctions of the interfacial nanostructures and properties between carbon fiber reinforced fast and conventional curing epoxy composites subjected to hydrothermal treatments

The vital role of the interphase in loading transfer in carbon fiber reinforced resin composites has received considerable critical attention. In this study, to quantitatively distinguish between the effects of hydrothermal aging on the interfacial nanostructures and properties of carbon fiber reinforced fast and conventional curing epoxy composites, peak force quantitative nano-mechanics (PF-QNM) technique by atomic force microscopy (AFM) was utilized to determine the interfacial modulus, adhesion and thickness. In addition, the shear behavior was studied by short-beam strength test, and the water uptake was investigated by water adsorption test. Based on the modulus contrast of the interphase in PF-QNM modulus image, the average interfacial thickness of the fast curing epoxy composites after 18 h of hydrothermal aging was 67 nm, increased 236 % when compared with the unaged composites. It was much higher than the rise of 70 % of the conventional curing epoxy composites after 18 h of hydrothermal aging while the interfacial thickness was 69 nm. Consistently, the average interfacial thickness of the fast and conventional curing epoxy composites determined by the adhesion were 68 nm (widened 247 %) and 68 nm (widened 67 %). In a word, the interfacial thickness of the fast curing epoxy composites was about 4 times than that of the conventional curing epoxy composites after 18 h of hydrothermal aging, because of the fast curing caused microcracks and flaws. Then, after 192 h of hydrothermal aging, the decreasing of short-beam strength of the fast curing epoxy composites were almost 1.6 times than that of the conventional curing epoxy composites, due to the faster growing of microcracks and delamination on the side surface of the fast curing epoxy composites short-beam samples during testing. Lastly, the maximum water absorption and diffusion coefficient of the fast curing epoxy composites were 1.2 % and 5.5 × 10−7 cm2/s respectively, which were both 1.3 times that of the conventional curing epoxy composites. Significantly, all the results proved that, attributing to the fast curing caused microcracks and flaws in the fast curing epoxy composites, through which water preferred to enter a composite along the fibers and interphase, the interphase in the fast curing epoxy composites were more sensitive to the hydrothermal aging than the conventional curing epoxy composites. Therefore, the water uptake, interfacial thickness and short-beam strength of the fast curing epoxy composites changed faster.

To Compare and Evaluate the Fracture Resistance of Three Post Endodontic Restorations Including Silver Amalgam, Dual Cure Composite Resin and Fibre Reinforced Composite Resin

Background: Endodontically treated teeth are thought to be more prone to fracture. The last stage in a successful root canal treatment is to restore root canal-treated teeth with a permanent, definitive postendodontic restoration. Dehydration, dentin loss during endodontic procedures, and the elimination of significant anatomic elements like cusps, ridges, and the pulp chamber's arched roof—all of which contribute significantly to the normal tooth's support—are the causes of the fracture of endodontically treated teeth. Consequently, intracoronal strengthening is necessary to prevent tooth fracture, especially in the posterior teeth where compressive stresses brought on by occlusal forces can cause tooth fractures.1 Since core materials typically replace a significant portion of the tooth structure and must withstand multidirectional masticatory forces,their compressive strength is crucial.2  Aim: The purpose of this study was to compare the compressive strengths of three direct post enododontic restorations.  Material and Methods: There are thirty extracted maxillary premolars chosen. After receiving root canal therapy, the teeth were divided randomly into three groups for immediate post-endodontic restorations: (i) silver amalgam (ii)Fiber-reinforced composite resin (iii) dual cure glass- reinforced composite resin . After that, a Universal Testing Machine was used to apply compressive stress on the teeth.  Statistical Analysis: Fracture loads will be compared statistically, and the data will be analysed using version 21.0 of SPSS software, analysis of variance and the Post-hoc test for multiple comparisons.  Result and Conclusion: Within the limits of the study, it showed that the post hoc tests reveal that the mean difference of compressive load strength is significant between all the groups, Amalgam has highest load strength followed by Fiber reinforced composite. Dual cure composite has lowest compressive load strength.

Effects of different surface treatments on surface topography and bond strength in the repair of fiber-reinforced dentin composite.

This study aimed to evaluate the effects of different surface treatments on the repair bond strength between a fiber-reinforced dentin composite and a posterior composite. Forty fiber-reinforced dentin composite resin blocks (4 mm × 4 mm × 4 mm) were separated into eight groups (n = 5) according to the surface preparation methods: (G1) negative control group, (G2) adhesive application, (G3) 50% dimethylsulfoxide (DMSO) application, (G4) 50% DMSO + adhesive application, (G5) 37% phosphoric acid etch + adhesive application, (G6) air abrasion + adhesive application, (G7) 37% phosphoric acid etch + 50% DMSO application + adhesive application, and (G8) air abrasion +50% DMSO application + adhesive application group. The composite surfaces were repaired in two layers with a posterior composite. Composite sticks were subjected to a micro tensile bond strength (μTBS) test. Fractured surfaces were evaluated using a stereomicroscope (×25). Short fiber-reinforced composite samples' surfaces were investigated by scanning electron microscope (SEM). Shapiro Wilk, one-way ANOVA, and Tukey HSD tests were used for statistical evaluation. The highest average (μTBS) values were observed in G8, whereas the lowest mean μTBS values were evident in the G1 group. Statistically significant μTBS values were found in all adhesive-applied groups when compared with the negative control group. Notably, the application of 50% DMSO without adhesive did not lead to a statistically significant increase in μTBS values. SEM images demonstrated that acid etching partially eliminated residues on the composite surface, while air abrasion had a detrimental effect on the integrity of fiber structures. In the repair of fiber-reinforced dentin composite with a posterior composite, adhesive application is an effective approach. The treatment of 50% DMSO without adhesive did not confer a statistically significant advantage, and the supplemental use of acid etch or air abrasion did not show an additional benefit compared to adhesive-only repairs. Adhesive application emerges as a potent and effective strategy for the repair of bur-roughened fiber-reinforced dentin composites. With its limitations, the study highlights the efficacy of adhesive-only repairs without the necessity for additional surface treatments.

Bond strength comparison of a fiber-reinforced composite resin: Different dentin conditions and preparation techniques.

This study aimed to compare the bond strength of a fiber-reinforced composite resin with traditional and bulk-fill composite resins under different dentin conditions and preparation techniques. Eighty molar teeth, excluding the mesio-distal half of the occlusal dentin surfaces of each teeth, were isolated with acid-resistant nail varnish and stored in a demineralisation solution (pH 4.5). After mechanical removal of the varnish, the teeth were buried in acrylic resin blocks. In every composite resin group, one-half of the specimens were prepared with a diamond bur and another half with Er: YAG laser. Then, the specimens were divided into four groups of composite resins (Filtek Z250, G-aenial Posterior, SonicFill 2, Ever X Posterior) (n = 10). Shear bond strengths were measured using a universal testing device, and failure types were determined with stereomicroscope images. SEM images were obtained at 1000× magnification. Data were analyzed using a three-way analysis of variance (ANOVA), and Bonferroni correction was used for multiple comparisons (p = .05). Differences in the dentin surface affected the bond strength results (p < .05), whereas there was no significant difference between cavity preparation methods (p > .05). EverX Posterior showed the highest bond strength results. Within the limitations of this study, fiber-reinforced composite resin exhibited successful bond strength results in addition to improved mechanical properties. RESEARCH HIGHLIGHTS: Fiber-reinforced composite had successful bond strength values. Bond strength values of sound dentin groups were higher than those of caries-affected dentin groups. The use of an Er: YAG laser for preparation did not lead to insufficient bond strength results.

A microcomputed tomography analysis of adaptation in premolars with flared root canals restored with different digitally custom fabricated post materials

Statement of problemPreserving and strengthening the remaining tooth structure of compromised flared root canals after endodontic treatment is challenging. PurposeThe purpose of this in vitro study was to compare the adaptation of milled polymer- infiltrated ceramic, fiber-reinforced composite resin, and high-performance semicrystalline thermoplastic resin posts as used to restore mandibular premolars with flared root canals. Material and methodsForty sound mandibular premolars were randomly divided into 4 groups: custom Vita Enamic (CV), custom fiber-reinforced composite resin (CF), custom polyetherketoneketone (CP), and prefabricated fiber (RF) posts. After endodontic treatment, each tooth was sectioned 1.5 mm occlusal to the cementoenamel junction. Then, the post space was prepared and flared, except the RF group, to a depth of 9 mm. The post space in RF group was prepared with a post drill. For the CV, CF, and CP groups, the posts were milled, finished, and cemented to their corresponding teeth. Each tooth was scanned using a microcomputed tomography device, and the reconstructed images were analyzed in mesiodistal, buccolingual, and horizontal planes. The cement thickness, cement volume, and volume of voids were measured. The data were analyzed using 3-way ANOVA (cement thickness) and 2-way ANOVA (cement volume and voids volume) tests followed by the post hoc Tukey test (α=.05). ResultsThe 3-way ANOVA test revealed a significant interaction (P<.001) between material type, section, and surface on the cement thickness. The mean cement thickness in the RF group was significantly higher than in the CV group (P=.001) and CF group (P=.005). The least mean cement thickness was at the apical section followed by the cervical and middle sections. Regarding cement volume, the 2-way ANOVA test showed statistically significant interaction between material type and section. The mean cement volume in the RF group was significantly lower than in the CV group (P=.001), CF group (P=.001), and CP group (P=.001). The highest mean cement volume was in the cervical section followed by the middle and apical sections. The 2-way ANOVA test showed statistically significant interaction (P<.001) between material type and section on the volume of voids. Significant differences were found between the mean volume of voids at the cervical and middle sections (P=.001) and the cervical and apical sections (P=.002). ConclusionsCompared with prefabricated fiber posts, digitally fabricated polymer-infiltrated ceramic and fiber-reinforced composite resin posts had a thinner cement layer with minimal thickness at the apical section. The digitally fabricated posts had higher cement volume, especially at the cervical section, than prefabricated fiber posts. High volumes of voids were related to the cervical section of all tested posts.

The influence of fitness and type of luting agents on bonding strength of fiber-reinforced composite resin posts

The influence of fitness and type of luting agents on bonding strength of fiber-reinforced composite resin posts

Novel stable aqueous emulsion of vinyl sizing agents for strong adhesion force between carbon fiber and vinyl resin

The sizing process is the best surface modification method to improve the interfacial properties of carbon fiber reinforced resin composites. In order to reinforce the interfacial adhesion of carbon fiber(CF)/vinyl resin (VE) composites, one novel emulsifying main slurry (NYDA) and resin (NE) were designed and synthesized from the view of the covalent bond between the CF and VE. The slurry NY-NE (2 wt% emulsion) exhibited excellent storage stability for three months. For introducing abundant active functional groups (C=C) to the NY-NE sized carbon fibers (NCF) surface, the interlaminar shear strength (ILSS) of NCF/VE composites (62.44 MPa) has increased by 69.31 % compared with unsizing carbon fiber (UCF)/VE composites (36.88 MPa). Moreover, the interfacial adhesion between CF and VE was also enhanced by the formation of C=C groups on the CFs surface to react with the VE effectively, which reinforced the interfacial layer to well transfer the load among the composite resin.

Bridging the Gap: A Case Report of Tooth Replacement using Resin-Bonded Fiber- Reinforced Composite Resin

This case report details the prosthetic replacement of a mobile mandibular left central incisor using a Fibre-Reinforced Composite resin (FRC) with a denture tooth pontic along with splinting of periodontally compromised teeth adjacent teeth. FRC is ideal because it offers excellent mechanical and esthetic properties, especially when combined with splinting for periodontally weakened teeth. The clinical procedure included selecting an acrylic denture tooth and bonding it to adjacent teeth using FRC without invasive tooth preparation procedures. The prosthetic tooth was shaped, polished, and finished to blend with the surrounding teeth, providing the patient with proper occlusion and esthetics. The patient experienced no discomfort or adverse effects during the follow-up period, and both the esthetic and functional outcomes were satisfactory. FRC offers a conservative, low-cost alternative to implant prostheses and can improve the patient’s long-term periodontal outcome. However, it is essential to note that regular follow-up visits and proper maintenance are necessary to prolong the lifespan of the restoration.

Effect of polyethylene fiber orientation on fracture resistance of endodontically treated premolars

Polyethylene fibers have been reported to improve the fracture resistance of endodontically treated teeth, but their optimal orientation is unclear. The purpose of this in vitro study was to evaluate the effects of different fiber positions and orientations on the fracture resistance of endodontically treated premolar teeth. One hundred endodontically treated maxillary premolars were divided into 2 groups according to the cavity design, mesio-occluso-distal and occluso-buccal, and each group was divided into 5 subgroups (n=10) according to the polyethylene fiber orientation on the pulpal floor: unidirectional horizontal (from mesial to distal), unidirectional vertical (from buccal to palatal), bidirectional (buccopalatal and mesiodistal), circular (around the walls), and without fibers (control group). The cavities were restored with fiber-reinforced composite resin and conventional composite resin. All the teeth were fractured with a universal testing machine and analyzed as catastrophic failure or reparable failure. A 1-way ANOVA was used to compare fracture strength values (α=.05). The tested groups with different fiber orientations showed significantly higher fracture load than the control group (P<.05). No statistically significant difference was observed among the fiber orientations (P>.05). Most of the favorable fractures were occlusal to the cemento-enamel junction, and adhesive failure were seen in the mesio-occluso-distal and occluso-buccal cavities. The highest percentage of unfavorable fractures and mixed failures was observed in the control group. The fiber orientation pattern in the mesio-occluso-distal and occluso-buccal cavities did not differ significantly in the fracture resistance of endodontically treated maxillary premolar teeth.

Evaluation of the Shear Bond Strength of Immediate and Delayed Restorations of Various Calcium Silicate-Based Materials with Fiber-Reinforced Composite Resin Materials.

Due to significant tissue loss in teeth requiring pulp treatments, hermetic restoration of the remaining dental tissues is one of the most crucial factors in determining the treatment's success. The adhesion of composite resins to calcium silicate cements (CSCs) is considered challenging. Consequently, it is crucial to identify the optimal method for obtaining optimal adhesion. The aim of the present study is to evaluate the shear bond strength (SBS) values of immediate and delayed restorations with fiber-reinforced composites on powder-liquid, premixed, and resin-containing flowable CSCs. In the present study, the SBS values obtained after immediate (14 min) and delayed (7 days) restorations of three different CSCs (NeoMTA2, NeoPutty, and TheraCal PT) with three different resin composite materials (EverX FlowTM, EverX PosteriorTM, and Filtek Z550) were compared. The fracture types were evaluated using a stereomicroscope and SEM. TheraCal PT had the highest SBS values for both immediate and delayed restorations, and the comparison with other materials showed a statistically significant difference (p = 0.001). In contrast, there was no statistically significant difference between the SBS values of NeoMTA and NeoPutty (p > 0.05). In both immediate and delayed restorations, there was no statistically significant difference between nanohybrid and fiber-reinforced composites (p > 0.05). The simple use and strong bonding ability of TheraCal PT with composite resins may provide support for the idea that it is suitable for pulpal interventions. Nevertheless, due to the in vitro nature of this study, additional in vitro and clinical studies are required to investigate the material's physical, mechanical, and biological properties for use in clinical applications.

Post-Endodontic Restorations Using Direct Fiber-Reinforced Composite Resins: A Case Report

Endodontically treated teeth always poses a challenge for dentists while reconstruction using the post and core system. This paper describes the clinical steps involved in reconstruction of maxillary anterior teeth. Endodontic treatment was performed first, followed by the placement of a fiber-reinforced resin post. The crown was then reconstructed with a composite restoration. Fiber posts have excellent properties, including elasticity, translucency, adaptability, tenacity, and resistance to traction and impact. They are also easy to apply, making them a viable alternative to traditional materials. The objectives of this article are to describe the various properties of fiber-reinforced composite resins with an exploration of their failure causes.

Performance of direct and indirect onlay restorations for structurally compromised teeth

Research is lacking on the restoration of structurally compromised posterior teeth using direct composite resin or indirect restorations. The purpose of this in vitro study was to measure the fracture resistance and microleakage of different onlay restorations fabricated by using conventional and digital computer-aided design and computer-aided manufacturing (CAD-CAM) to restore structurally compromised teeth. Mandibular molars (n=54) were prepared for onlay restorations. Teeth were allocated to 3 groups (n=18) according to the type of restoration materials, nanohybrid composite resin (Grandio blocs), resin hybrid ceramic (SHOFU Block HC), and fiber-reinforced composite resin (everX Posterior). Onlays were bonded using a dual-polymerized adhesive resin cement. All specimens were thermocycled, followed by cyclic loading. Based on the type of investigation conducted, fracture resistance, and microleakage test, each group was then divided into 2 equal subgroups (n=9). The collected data were statistically analyzed with the chi-square of the Fischer exact test (α=.05). Fracture resistance testing revealed a statistically significant difference between groups (P<.001). The fiber-reinforced composite resin demonstrated the highest fracture resistance, with statistically significantly less microleakage compared with the other groups (P=.013). Direct fiber-reinforced composite resin could be considered a suitable alternative to CAD-CAM composite resin for the restoration of structurally compromised teeth.

Restoration of a Vital Tooth With Extensive Crown Destruction Using Glass Fiber and Polyethylene Fiber-reinforced Composite Resin: A Clinical Case.

Conservative restorative dentistry has been evolving in the last 25 years, focusing mainly on the development of direct restorative materials. Resin-based composites remain an excellent conservative alternative for restoration of teeth with extensive caries lesions. Over time, several strategies have been proposed to improve the mechanical properties of these composites so that they can adequately withstand masticatory forces. Glass fiber-reinforced resin-based composites and their use in situations where there is great loss of tooth structure have gained popularity due to their favorable mechanical properties. Combined techniques with polyethylene fibers can further enhance their clinical performance. This study presents a brief review of their most important qualities and potential use in direct restorative procedures. In addition, a clinical case is described where a vital tooth with extensive coronal destruction was restored using polyethylene fibers embedded in glass fiber-reinforced flowable resin under resin-based composite. The reinforcement of both the remaining tooth structure and the restoration with fibers is a valid treatment option since the network structure formed by the fiber reinforcement can increase the longevity of the direct composite restorations. There are few reports in the literature describing the use of a combined technique using polyethylene fibers embedded in glass fiber-reinforced flowable resin under resin-based composite. Thus, clinical follow-up of this case is required.

Evaluation of Stress Distribution in Root Canal Treated Maxillary Incisors Treated with Different Fiber-Reinforced Composite Resins by Finite Element Analysis

Amaç: Bu çalışmanın amacı, maksiller kesici dişte horizontal ve oblik iki farklı kırık tipine sahip diş modellerinde farklı fiberle güçlendirilmiş kompozit rezin (FGKR) restorasyonlarının fonksiyonel kuvvetler altında oluşturduğu stresin sonlu elemanlar analizi (SEA) yöntemiyle değerlendirilmesidir. &#x0D; Materyal ve Metod: Kök gelişimi tamamlanmış bir maksiller kesici diş mikrobilgisayarlı tomografi cihazında taranmıştır. Elde edilen bilgilerle üç boyutlu kök gelişimi tamamlanmış maksiller kesici diş modeli oluşturularak, horizontal ve oblik kırığa sahip iki farklı grup oluşturulmuştur. Örnek model esas alınarak, kök kanal tedavisi yapılmış horizontal ve oblik kırık hattı oluşturulmuş, maksiller kesici diş modelleri farklı FGKR ile restore edilerek üç boyutlu olarak simüle edilmiştir. Ardından dişlerde fonksiyonel kuvvet altında oluşan stresler SEA yöntemiyle değerlendirilmiştir.&#x0D; Bulgular: FGKR kullanılan modellerde kök dentininin servikal bölgesi ve restoratif materyalde oluşan stresler azalmıştır. Tüm modeller incelendiğinde hem kök dentininin servikal bölgesinde hem de restoratif materyalde en yüksek stres değerleri yalnızca kompozit rezin kullanılan modellerde görülmüştür. En düşük stres değerleri ise prefabrik uzun cam fiber post kullanılan modellerde görülmüştür. Horizontal kırık hattına sahip olan modellerde oblik kırık hattına sahip modellere göre oluşan streslerin daha fazla olduğu görülmüştür.&#x0D; Sonuç: Kron fraktürüne sahip dişlerde FGKR kullanımı hem kök dentininin servikal bölgesinde oluşan stresleri hem de restoratif materyaldeki stresleri azaltmaya yardımcı olacaktır.

Use of fiber-containing materials in restorative dentistry

It is aimed at providing chewing function in restorative treatment in dentistry, to protect the tooth structure based on the minimally invasive approach and to meet the aesthetic expectations of the patient. Studies including application techniques are carried out to improve the mechanical and physical properties of composite resins and to reduce polymerization shrinkage. The success of composite restorations has increased with the use of fibers and fiber-reinforced composite resin materials, and the indications of composite resins as direct restoration material have expanded thanks to the production of newly developed fiber-reinforced composite resin materials and their use with the biomimetic restoration technique. In this review, information about the properties and types of fiber structures, advantages, disadvantages, and application areas is explained.

Effect of Different Silane Coupling Agents on the Bond Strength between Hydrogen Peroxide-Etched Epoxy-Based- Fiber-Reinforced Post and Composite Resin Core.

The aim of the study was to evaluate the effect of various silane coupling agents on the micro-push-out bond strength between a hydrogen peroxide-etched epoxy-based fiber-reinforced post and composite resin core. Seventy-five cross-linked epoxy-based fiber-reinforced posts were etched with 24% hydrogen peroxide for 10 min. Then they were divided into five groups according to various silane coupling agents and bonded to a composite core. A Universal Testing Machine was utilized to evaluate the push-out bond strength. In addition, all groups' modes of failure were assessed. The push-out bond strength data in MPa were analyzed using ANOVA and a Tukey HSD post hoc test to reveal any difference between the groups. Results revealed that the application of a two-bottle silane coupling agent exhibited the highest bond strength, while the application of a one-bottle silane coupling agent demonstrated the lowest bond strength for a hydrogen peroxide-etched fiber post bonded to a composite core material, which was statistically significant (p < 0.05). The strongest association with the highest bond strength was found with the two-bottle silane coupling agent when compared to the one-bottle. The study highlighted that the application of a silane-coupling agent may affect the bond strength between composite and epoxy-based fiber-reinforced posts.

An interlayer flame retardant method to effectively fire retardant and reinforce CF/EP composites by nanofiber film intercalation

As an advanced material with wide application, carbon fiber reinforced epoxy resin matrix composites (CF/EP) are flammable, but the traditional flame retardant methods negatively affect its molding process, heat resistance, mechanical properties, and how to solve this problem has been a challenge. This paper adopts a novel flame retardant method of inserting nanofiber films of flame retardant into the interlayer of the composite laminate to achieve fire resistance, higher strength, and toughness of the composite. In this work, pentaerythritol phosphate (PEPA) nanofiber films with phenoxy resin (PKHH) as a carrier was prepared by electrospinning and placed between the layers of CF/EP laminates. The results show that a dense charring layer with isolation and protection functions can be formed between the layers of the CF/EP intercalated by the nanofiber films during combustion. Accordingly, the nanofiber film containing 50 wt% PEPA with the thickness of only 30 μm increased the LOI value of CF/EP from 27.8% to 34.7%, while reducing the THR and pSD by 14% and 27.2% respectively. What’s more, due to the Ex-situ toughening effect of the nanofibers, the flexural strength, interlaminar shear strength, and compression strength after the impact of the modified CF/EP were increased by a maximum of 11.2%, 11.3%, and 12.2% compared to unmodified CF/EP. This work proves the feasibility of interlayer flame retardant fiber reinforced resin composites, and provides a new method to prepare high-performance flame-retardant composites.

Hybrid layout and additive manufacturing of continuous carbon/glass fibers reinforced composites, and its effect on mechanical properties

Material extrusion has been applied to the preparation of continuous fiber reinforced resin composites successfully. However, due to the limitations of the characteristics of a single fiber material, the prepared composites usually can only obtain the reinforcement of a single properties. In this study, the effects of the content ratio and arrangement mode of carbon/glass fiber layers in the 3D printed composites on tensile and impact properties were investigated, and the influence of mixed fibers was analyzed by failure morphology. The hybrid continuous carbon/glass fiber reinforced nylon composite parts with good balanced tensile and impact properties were obtained in the experiment, compared with single carbon fiber reinforced nylon composites, the impact strength increased to 250% of the original, while the tensile strength lost only 7%. Tensile strength and impact strength of the printed hybrid composites with the same fiber content and different arrangement are different by 20% and 35%, respectively. The tensile strength of 3D printed hybrid continuous fiber composites was accurately predicted by establishing a model considering hybrid effect.

Progressive conductivity modular assembled fiber reinforced polymer composites for absorption dominated ultraefficient electromagnetic interference shielding

Mechanical strong and durable fiber reinforced polymer composites (FRPC) with adjustable electromagnetic interference (EMI) shielding performance are urgently needed due to the rapid growing of electronics in civil and military fields. However, regulating the electromagnetic feature of fiber reinforced resin composites for tunable and absorption-dominated EMI shielding performance is still a great challenge due to the fixed electromagnetic properties of the continuous fabrics. Herein, an ultraefficient fiber reinforced epoxy resin EMI shielding composite with extremely low reflection, adjustable electromagnetic shielding feature and strong mechanical properties is fabricated through a facile progressively conductive fabric modular assembly. By decorating electromagnetic particles to obtain customized electromagnetic functional fiber cloths and progressively conductive modular design, this multi-layered fiber reinforced epoxy resin composites enable the arbitrary regulation of the electromagnetic wave reflection and absorption capabilities, leading to an excellent average EMI shielding effectiveness of 78.6 dB and extremely low reflectivity (R) of 0.05 in X-band frequency range. In addition, benefitting from the reasonable fabric arrangement and asymmetric layered structure, the composite also exhibits excellent mechanical properties. The tensile strength is 283.1 MPa, and the energy absorption reached 15.9 J under the impact of 20 J. Our work demonstrated that this progressive conductivity modular assembly is a reliable and efficient strategy to develop highly efficient EMI shielding FRPC composites with adjustable and absorption-dominated shielding feature, and is highly promising for applications in next-generation electronic devices.