Journal of Composites Science

Research

Jump to: Review

22 pages, 7322 KB

Open AccessArticle

Performance of Pultruded FRP Beam-Column Connections Under Different Design Parameters

by Said Abdel-Monsef, Alaa Elsisi, Hassan Maaly and Ossama El-Hosseiny

J. Compos. Sci. 2025, 9(9), 487; https://doi.org/10.3390/jcs9090487 - 8 Sep 2025

Viewed by 478

Abstract

In frame structures, connections play a vital role in governing both serviceability and ultimate strength. For pultruded fiber-reinforced polymer (PFRP) frames, connection design is even more critical due to the anisotropic and viscoelastic nature of the composite materials used in the primary elements [...] Read more.

In frame structures, connections play a vital role in governing both serviceability and ultimate strength. For pultruded fiber-reinforced polymer (PFRP) frames, connection design is even more critical due to the anisotropic and viscoelastic nature of the composite materials used in the primary elements (e.g., beams and columns) and their joints. This study presents a finite element model (FEM) to evaluate the influence of several connection parameters—namely, connection stiffening, bolt diameter, washer diameter, and clamping force—on the elastic behavior of beam-column joints composed of PFRP elements. The results demonstrate that stiffening the upper and lower connection angles significantly enhances joint performance. Increasing the bolt diameter improves moment capacity, reduces rotational deformation, decreases stress concentrations around bolt-hole edges, and increases both minor principal and compressive stresses beneath the bolt shank. Similarly, a larger washer diameter contributes to higher connection stiffness and reduces stress concentrations at bolt holes. Although the clamping force has a relatively modest effect on global connection behavior, it positively influences the through-thickness stress distribution in the angle beneath the bolt shank. Finally, regression equations were developed to quantify the relationship between rotation, moment, bolt diameter, washer diameter, and clamping force, providing a valuable tool for the design and optimization of PFRP connections in structural applications. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

25 pages, 7254 KB

Open AccessArticle

Punching Strengthening of Lightweight Aggregate Reinforced Concrete Flat Slabs Using Fiber-Reinforced Polymers

by Esraa Abaza, Mohamed T. Elshazli, Ahmed Elbelbisi, Hamdy Shehab and Mahmoud Zaghlal

J. Compos. Sci. 2025, 9(9), 485; https://doi.org/10.3390/jcs9090485 - 7 Sep 2025

Viewed by 585

Abstract

Lightweight Aggregate Reinforced Concrete (LWARC) is increasingly used in structural systems to reduce dead load, especially in flat slabs. This study focuses on LWARC-incorporating polystyrene foam as a partial aggregate replacement, achieving a dry unit weight reduction from 23.0 kN/m³ to 19.0 [...] Read more.

Lightweight Aggregate Reinforced Concrete (LWARC) is increasingly used in structural systems to reduce dead load, especially in flat slabs. This study focuses on LWARC-incorporating polystyrene foam as a partial aggregate replacement, achieving a dry unit weight reduction from 23.0 kN/m³ to 19.0 kN/m³. While beneficial for lowering dead loads, this substitution exacerbates punching shear vulnerability, necessitating innovative strengthening solutions. Fiber-Reinforced Polymers (FRPs), recognized for their high strength-to-weight ratio, corrosion resistance, and adaptability, are employed to address these limitations. This paper evaluates the punching shear strengthening of LWARC flat slabs using externally bonded carbon fiber-reinforced polymer (CFRP) sheets, embedded through-section (ETS) steel bars, and ETS glass fiber-reinforced polymer (GFRP) bars. Ten specimens were tested under concentric loading, including an unstrengthened control slab. Experimental results were compared with predictions from ECP 203-2023, ACI 318-19, and BS 8110 to assess code applicability. Strengthened specimens demonstrated significant improvements in punching capacity and ductility. The ETS steel bar technique increased punching strength by 41% compared to the control, while inclined reinforcement configurations outperformed vertical layouts by 24% due to optimized shear transfer. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

27 pages, 4573 KB

Open AccessFeature PaperArticle

Basalt vs. Glass Fiber-Reinforced Polymers: A Statistical Comparison of Tribological Performance Under Dry Sliding Conditions

by Corina Birleanu, Razvan Udroiu, Mircea Cioaza, Paul Bere and Marius Pustan

J. Compos. Sci. 2025, 9(8), 444; https://doi.org/10.3390/jcs9080444 - 18 Aug 2025

Viewed by 904

Abstract

The variety of fiber types embedded in fiber-reinforced polymer (FRP) composites determines different tribology performance properties. In this work, the tribological properties under dry sliding conditions of glass fiber-reinforced polymer (GFRP) and basalt fiber-reinforced polymer (BFRP) were investigated and compared. Laminated composite specimens [...] Read more.

The variety of fiber types embedded in fiber-reinforced polymer (FRP) composites determines different tribology performance properties. In this work, the tribological properties under dry sliding conditions of glass fiber-reinforced polymer (GFRP) and basalt fiber-reinforced polymer (BFRP) were investigated and compared. Laminated composite specimens with different fiber content were manufactured by vacuum bagging and autoclave curing. Tensile and flexural mechanical properties, as well as pin-on-disk tribological properties of the composite specimens, were analyzed. A design of experiments was performed considering the influence of fiber weight fraction, fiber type, and sliding speed on the coefficient of friction (COF), specific wear rate (K), and contact temperature. A multifactorial ANOVA was performed to identify the significance and contribution percentage of each factor. Deep investigations to understand the wear mechanisms were performed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results of the statistical analysis showed that the interaction between fiber type and sliding speed had the most significant influence on the COF (31.36%), while the fiber weight fraction had the predominant effect on the specific wear rate (22.04%), and the sliding speed was the most influential factor affecting temperature (82.88%). BFRP composites consistently performed better than GFRP in all tribological metrics, such as coefficient of friction, specific wear rate, and contact temperature. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

26 pages, 7205 KB

Open AccessArticle

Influence of Different Dosages of Rice Husk Particles on Thermal, Physical, Mechanical and Rheological Properties of Polypropylene-Based Composites

by Ilnur Fayzullin, Aleksandr Gorbachev, Svetoslav Volfson, Gulnur Zhakypova, Saken Uderbayev, Abdirakym Nakyp and Nurgali Akylbekov

J. Compos. Sci. 2025, 9(8), 443; https://doi.org/10.3390/jcs9080443 - 17 Aug 2025

Viewed by 1022

Abstract

This study investigates the effect of rice husk content (0–60 wt.%) on the thermal, mechanical and rheological properties of polypropylene composites prepared by extrusion and injection molding. A temperature-invariant approach was applied to analyze the viscoelastic properties, allowing the combination of data obtained [...] Read more.

This study investigates the effect of rice husk content (0–60 wt.%) on the thermal, mechanical and rheological properties of polypropylene composites prepared by extrusion and injection molding. A temperature-invariant approach was applied to analyze the viscoelastic properties, allowing the combination of data obtained at different temperatures. The results show that as the husk content increases, the elastic modulus and hardness rise linearly, while the impact strength and elongation at break significantly decrease. Composites with 40–50% filler exhibit a balanced combination of strength and stiffness, as confirmed by the summary data in the table (provide references). The application of the temperature-invariant viscosity method confirmed its effectiveness in evaluating the flow properties of composite melts. The obtained results have practical significance for the development of eco-friendly polymer materials with natural fiber fillers. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

11 pages, 1617 KB

Open AccessArticle

Mechanics of Interfacial Debonding in FRP Strengthening Systems: Energy Limits and Characteristic Bond Lengths

by Nefeli Mitsopoulou and Marinos Kattis

J. Compos. Sci. 2025, 9(8), 412; https://doi.org/10.3390/jcs9080412 - 4 Aug 2025

Viewed by 659

Abstract

This study examines the energy behavior of a strengthening system consisting of a Fiber Reinforced Polymer (FRP) plate bonded to a rigid substrate and subjected to tensile loading, where the adhesive interface is governed by a bilinear bond–slip law with a vertical descending [...] Read more.

This study examines the energy behavior of a strengthening system consisting of a Fiber Reinforced Polymer (FRP) plate bonded to a rigid substrate and subjected to tensile loading, where the adhesive interface is governed by a bilinear bond–slip law with a vertical descending branch. The investigation focuses on the interaction between the elastic energy stored in the FRP and the adhesive interface, as well as the characteristic lengths that control the debonding process. Analytical expressions for the strain energy stored in both the FRP plate and the adhesive interface are derived, enabling the identification and evaluation of two critical characteristic lengths as the bond stress at the loaded end approaches its maximum value

l_{c}

, at which the elastic energies of the FRP and the adhesive interface converge, signaling energy saturation; and

l_{m a x}

, where the adhesive interface attains its peak energy absorption. Upon reaching the energy saturation state, the system undergoes failure through the sudden and complete debonding of the FRP from the substrate. The onset of unstable debonding is rigorously analyzed in terms of the first and second derivatives of the total potential energy with respect to the bond length. It is further demonstrated that abrupt debonding may also occur in cases where the length exceeds

l_{c}

when the bond stress reaches its maximum, and the bond–slip law is characterized by a vertical branch. The findings provide significant insights into the energy balance and stability criteria governing the debonding failure mode in FRP-strengthened structures, highlighting the pivotal role of characteristic lengths in predicting both structural performance and failure mechanisms. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

23 pages, 2793 KB

Open AccessArticle

Doping Carbon Coating on Glass Fiber to Enhance Its Reinforcing Potential in a Polymer Matrix

by Siok Wei Tay, Inez Lau and Liang Hong

J. Compos. Sci. 2025, 9(7), 348; https://doi.org/10.3390/jcs9070348 - 6 Jul 2025

Viewed by 705

Abstract

This research investigates a novel hybrid E-glass fiber coated with a thin amorphous carbon (coke) layer, referred to as GF@C, designed to enhance the affinity of fiber with a polymer matrix. Acrylonitrile butadiene styrene (ABS), an engineering thermoplastic, was selected as the matrix [...] Read more.

This research investigates a novel hybrid E-glass fiber coated with a thin amorphous carbon (coke) layer, referred to as GF@C, designed to enhance the affinity of fiber with a polymer matrix. Acrylonitrile butadiene styrene (ABS), an engineering thermoplastic, was selected as the matrix to form the composite. The carbon coating was produced by pyrolyzing a lubricant oil (Lo) layer applied to the glass fiber strands. To promote the formation of graphite crystallites during carbonization, a small amount (x wt.% of Lo) of coronene (Cor) was added to Lo as a dopant. The resulting doped fibers, denoted GF@C_Lo-Cor(x%), were embedded in ABS at 70 wt.%, leading to significant improvements in mechanical properties. At the optimal doping level (x = 5), the composite achieved a Young’s modulus of 1.02 GPa and a tensile strength of 6.96 MPa, substantially higher than the 0.4 GPa and 3.81 MPa observed for the composite with the pristine GF. This enhancement is attributed to a distribution of graphite crystallites and their graphitization extent in the carbon coating, which improves interfacial bonding and increases chain entanglement. Additionally, GF@C_Lo-Cor(x%)–ABS composites (x = 0 and 5) exhibit significantly higher dielectric constant–temperature profiles than GF–ABS, attributed to the formation of diverse chain adsorption states on the C-coating. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Graphical abstract

12 pages, 2165 KB

Open AccessArticle

Flexible Piezoresistive Sensors Based on PANI/rGO@PDA/PVDF Nanofiber for Wearable Biomonitoring

by Hong Pan, Yuxiao Wang, Guangzhong Xie, Chunxu Chen, Haozhen Li, Fang Wu and Yuanjie Su

J. Compos. Sci. 2025, 9(7), 339; https://doi.org/10.3390/jcs9070339 - 30 Jun 2025

Cited by 2 | Viewed by 742

Abstract

Fibrous structure is a promising building block for developing high-performance wearable piezoresistive sensors. However, the inherent non-conductivity of the fibrous polymer remains a bottleneck for highly sensitive and fast-responsive piezoresistive sensors. Herein, we reported a polyaniline/reduced graphene oxide @ polydopamine/poly (vinylidene fluoride) (PANI/rGO@PDA/PVDF) [...] Read more.

Fibrous structure is a promising building block for developing high-performance wearable piezoresistive sensors. However, the inherent non-conductivity of the fibrous polymer remains a bottleneck for highly sensitive and fast-responsive piezoresistive sensors. Herein, we reported a polyaniline/reduced graphene oxide @ polydopamine/poly (vinylidene fluoride) (PANI/rGO@PDA/PVDF) nanofiber piezoresistive sensor (PNPS) capable of versatile wearable biomonitoring. The PNPS was fabricated by integrating rGO sheets and PANI particles into a PDA-modified PVDF nanofiber network, where PDA was implemented to boost the interaction between the nanofiber networks and functional materials, PANI particles were deposited on a nanofiber substrate to construct electroactive nanofibers, and rGO sheets were utilized to interconnect nanofibers to strengthen in-plane charge carrier transport. Benefitting from the synergistic effect of multi-dimensional electroactive materials in piezoresistive membranes, the as-fabricated PNPS exhibits a high sensitivity of 13.43 kPa⁻¹ and a fast response time of 9 ms, which are significantly superior to those without an rGO sheet. Additionally, a wide pressure detection range from 0 to 30 kPa and great mechanical reliability over 12,000 cycles were attained. Furthermore, the as-prepared PNPS demonstrated the capability to detect radial arterial pulses, subtle limb motions, and diverse respiratory patterns, highlighting its potential for wearable biomonitoring and healthcare assessment. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

13 pages, 17065 KB

Open AccessArticle

Eco-Friendly Magnetically Active Textiles: Influence of Magnetic Fields, Pumpkin Seed Oil, and Propolis Microparticles on Complex Dielectric Permittivity Components

by Ioan Bica, Eugen Mircea Anitas, Gabriela Eugenia Iacobescu and Larisa Marina Elisabeth Chirigiu

J. Compos. Sci. 2025, 9(5), 237; https://doi.org/10.3390/jcs9050237 - 9 May 2025

Cited by 1 | Viewed by 823

Abstract

This study presents the fabrication and characterization of magnetically active textiles using cotton fibers impregnated with suspensions of pumpkin seed oil, carbonyl iron microparticles, and propolis microparticles. The textiles were utilized to manufacture planar capacitors, enabling an investigation of the effects of static [...] Read more.

This study presents the fabrication and characterization of magnetically active textiles using cotton fibers impregnated with suspensions of pumpkin seed oil, carbonyl iron microparticles, and propolis microparticles. The textiles were utilized to manufacture planar capacitors, enabling an investigation of the effects of static magnetic fields and the introduced microparticles on the components of complex dielectric permittivity. The results reveal that the dielectric properties of the fabricated textiles are highly sensitive to the applied magnetic field intensity, the frequency of the alternating electric field, and the composition of the impregnating suspension. The experimental findings suggest that the dielectric loss and permittivity can be finely tuned by adjusting the magnetic flux density and the proportion of propolis microparticles. The multifunctional nature of these magnetically responsive textiles, combined with the bioactive properties of the incorporated natural components, opens promising pathways for applications in smart textiles, biomedical devices, and sensor technologies. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

17 pages, 5233 KB

Open AccessArticle

Anisotropy and Strain Rate Sensitivity of Additively Manufactured Polymer Composites in Tension and Compression: Effects of Type and Orientation of Fibres

by Md Niamul Islam, Konstantinos P. Baxevanakis and Vadim V. Silberschmidt

J. Compos. Sci. 2025, 9(4), 186; https://doi.org/10.3390/jcs9040186 - 11 Apr 2025

Viewed by 814

Abstract

Comprehensive analysis of the anisotropic nature of additively manufactured (AM) parts caused by their fabrication method requires attention, as current quasi-static experiments on AM specimens are used to determine strength and stiffness. This study investigates the anisotropic mechanical behaviour of AM polymer composites [...] Read more.

Comprehensive analysis of the anisotropic nature of additively manufactured (AM) parts caused by their fabrication method requires attention, as current quasi-static experiments on AM specimens are used to determine strength and stiffness. This study investigates the anisotropic mechanical behaviour of AM polymer composites reinforced with short and continuous carbon fibres, examining various filament orientations, loading directions and strain rates. Utilising the fused deposition modelling (FDM) technique, nylon and carbon fibres were fabricated into composites with controlled orientations. Mechanical tests were conducted in different directions to assess the tensile and compressive properties of these composites, with results showing enhanced tensile strength and stiffness in continuous-fibre (CF) composites compared to short-fibre (SF) ones, particularly in longitudinal orientations. The compressive behaviour revealed complex effects of type and orientation of reinforcing fibres, with CF composites demonstrating superior stiffness but lower strength than SF composites in specific orientations. Strain rate sensitivity analysis for the least anisotropic (quasi-isotropic) cases indicated that tensile strength decreased slightly with the increased strain rate while compressive strength increased. These findings underline the critical effect of fibre orientation and type on mechanical properties and suggest potential applications of AM composites in scenarios demanding tailored anisotropic behaviours, including structural optimisation and numerical modelling for various loading conditions. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

26 pages, 25600 KB

Open AccessArticle

Enhancing Mechanical Properties of 3D-Printed PLA Composites Reinforced with Natural Fibers: A Comparative Study

by Nisakorn Somsuk, Supaaek Pramoonmak, Boonsong Chongkolnee, Ponlapath Tipboonsri and Anin Memon

J. Compos. Sci. 2025, 9(4), 180; https://doi.org/10.3390/jcs9040180 - 8 Apr 2025

Cited by 4 | Viewed by 2119

Abstract

Polylactic acid (PLA) is widely used in 3D printing for its biodegradability and ease of processing, but its brittleness and low impact strength often restrict its suitability for more demanding applications. The novelty of this work lies in its direct comparative approach: we [...] Read more.

Polylactic acid (PLA) is widely used in 3D printing for its biodegradability and ease of processing, but its brittleness and low impact strength often restrict its suitability for more demanding applications. The novelty of this work lies in its direct comparative approach: we systematically reinforce PLA with two distinct agricultural residues—rice husk and rice straw—under identical conditions to clarify how particle size (100 vs. 200 mesh) and NaOH surface treatment affect mechanical performance. Composite filaments containing 5–20 wt% of each fiber were produced and 3D-printed into standard tensile and flexural specimens. The results show that, although tensile strength declines at higher fiber loadings, tensile modulus, flexural strength, and impact resistance can improve significantly—particularly with 200-mesh and NaOH-treated fibers. Fourier transform infrared (FTIR) spectroscopy confirms partial lignin removal and enhanced cellulose exposure, improving fiber–matrix adhesion, which is corroborated by scanning electron microscopy (SEM) observations of reduced voids. This comparative study demonstrates that surface-treated, finely milled rice husk and rice straw significantly enhance PLA’s stiffness and toughness, offering a sustainable alternative to conventional polymeric additives. The insights gained here on fiber content, chemical treatment, and 3D printing parameters can guide the broader industrial adoption of these natural fiber-reinforced PLA composites, particularly in automotive and construction applications that require lightweight, durable materials. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

24 pages, 9732 KB

Open AccessArticle

Development and Validation of a Desktop 3D Printing System with Thermo-Mechanical In Situ Consolidation for Continuous Fiber-Reinforced Polymer Composites

by Hannes Oberlercher, Marius Laux, Gean Henrique Marcatto de Oliveira and Sergio T. Amancio-Filho

J. Compos. Sci. 2025, 9(3), 128; https://doi.org/10.3390/jcs9030128 - 10 Mar 2025

Viewed by 2171

Abstract

A controlled laminate consolidation is one of the most essential approaches in the production of fiber-reinforced thermoplastics components. With the use of specific consolidation models, almost the entire strength potential of the material can be exploited. However, a controlled thermo-mechanical in situ consolidation [...] Read more.

A controlled laminate consolidation is one of the most essential approaches in the production of fiber-reinforced thermoplastics components. With the use of specific consolidation models, almost the entire strength potential of the material can be exploited. However, a controlled thermo-mechanical in situ consolidation (TMIC) strategy in the fused filament fabricated (FFF) process of continuous fiber-reinforced polymer composites (CFRPC) has not been considered so far and leads to deconsolidation defects in the 3D-printed material. These defects in terms of micro and macro volumetric flaws in the joining zone indicate a poor process parameter selection and inadequate thermo-mechanical consolidation. These imperfections lead to a reduction in the fiber volume content and a significant deterioration in the mechanical properties. In this work, a self-developed test rig is presented, which is able to influence and monitor the consolidation during the additive manufacturing (AM) process with a TMIC unit in a controlled manner. To evaluate the test rig, the mechanical construction and the implemented sensors were tested for full functionality. Subsequently, test specimens were fabricated for mechanical characterization using three-point bending (3PB) tests and microstructural analysis. Based on these results, the influence of TMIC, with its dependent process parameters (consolidation force, temperature, printing speed), is presented. A perspective on the future development of controlled consolidation in AM of CFRPC is shown. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Graphical abstract

21 pages, 9879 KB

Open AccessArticle

High-Cycle Fatigue Behaviour and Structural Robustness of Glass Fibre-Reinforced Polymer Tiled Web-Core Sandwich Panel Unit Cells in Load-Bearing Structures

by Jordi Uyttersprot, Wouter De Corte and Wim Van Paepegem

J. Compos. Sci. 2024, 8(12), 538; https://doi.org/10.3390/jcs8120538 - 17 Dec 2024

Cited by 1 | Viewed by 959

Abstract

This paper explores the fatigue behaviour and robustness of tiled web-core sandwich panels used in glass fibre-reinforced polymer bridges, which are increasingly favoured for their lightweight and corrosion-resistant properties. Fatigue tests are conducted on unit cell specimens with manually induced crack initiation, simulating [...] Read more.

This paper explores the fatigue behaviour and robustness of tiled web-core sandwich panels used in glass fibre-reinforced polymer bridges, which are increasingly favoured for their lightweight and corrosion-resistant properties. Fatigue tests are conducted on unit cell specimens with manually induced crack initiation, simulating accidental damage scenarios in glass fibre-reinforced polymer bridge components. The objective is to assess the integrity of individual unit cells when subjected to a localized force at the top flange after damage initiation. The fatigue tests reveal three phases in the behaviour of a tiled unit cell. Initially, there is a substantial rapid stiffness degradation with crazing crack appearance within the cross-section. Subsequently, a plateau phase occurs, with limited stiffness degradation and stable crazing cracks, the duration of which depends on the applied fatigue load. Lastly, rapid stiffness degradation with substantial crack growth leads to ultimate failure within roughly a thousand cycles. Further analysis using digital image correlation reveals strain concentrations at the location of crazing cracks and crack propagation occurring interlaminarly but not through the plies of the top and bottom flanges, ensuring a robust design. This research enhances the understanding of the tiled sandwich panels, offering prospects for resilient load-bearing structures in glass fibre-reinforced polymer bridges and structural engineering applications. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

13 pages, 3213 KB

Open AccessArticle

Tailored Compositions of Ni-Ti-Sn Nanopowders Deposited on Polymer Fiber Optics Through Flash Evaporation

by Elango Natarajan, Anil Chouhan, Santheraleka Ramanathan, Kalaimani Markandan, Santhosh Mozhuguan Sekar, Chun Kit Ang, Nagarajan Deivanayagampillai and Gérald Franz

J. Compos. Sci. 2024, 8(12), 526; https://doi.org/10.3390/jcs8120526 - 13 Dec 2024

Cited by 1 | Viewed by 1024

Abstract

Fiber coatings protect the glass surface of fiber from extrinsic environmental factors. The coating of shape memory alloy over fiber is useful in sensor fabrication where the state of deformation is affected by the phase transformation of the coated material. In addition, coated [...] Read more.

Fiber coatings protect the glass surface of fiber from extrinsic environmental factors. The coating of shape memory alloy over fiber is useful in sensor fabrication where the state of deformation is affected by the phase transformation of the coated material. In addition, coated plastic fibers can be used in elevated temperature environments. To this end, the present research aims to investigate the effect of the Ni-Ti-Sn composite coating over the fiber. Homogeneous particle distribution, agglomeration, porosity and the ability to obtain uniform coating thickness have been general concerns in fiber coatings. Hence, the present study comprehensively investigated the mechanical and thermal behavior as well as morphological properties of Ni-Ti-Sn nanopowders deposited on polymer fiber optics. Five sets of polyamide-coated samples with different Ni-Ti-Sn proportions were fabricated and characterized. Morphological studies confirmed that an even coating thickness enhanced the mechanical integrity and optical performance. The optimum composition demonstrated superior tensile strength of 29.5 MPa and a 25% increase in elongation compared to the uncoated sample. The Ni-Ti-Sn alloy composition investigated in the present study is promising for industrial applications where thermal stability and mechanical performance are warranted. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

14 pages, 11409 KB

Open AccessArticle

Mesoscopic Simulation on Centrifugal Melt Electrospinning of Polyetherimide and Polyarylethernitrile

by Han Guo, Yuzhe Huang, Jia Chen, Hongyu Huo, Gongqiu Peng, Baoyan Zhang and Yong Liu

J. Compos. Sci. 2024, 8(11), 480; https://doi.org/10.3390/jcs8110480 - 19 Nov 2024

Viewed by 1101

Abstract

Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains [...] Read more.

Polyetherimide (PEI) and polyarylethernitrile (PEN) are high–performance materials for various applications. By optimizing their fiber morphology, their performance can be further enhanced, leading to an expanded range of applications in carbon fiber composites. However, developing processes for stable and efficient fiber production remains challenging. This research aims to simulate the preparation of high–performance ultrafine PEI or PEN fibers using electrospinning. A mesoscopic simulation model for centrifugal melt electrospinning was constructed to compare and analyze the changes in molecular chain orientation, unfolding, fiber diameter, and fiber yield under high-voltage electrostatic fields. The simulation results showed that temperature and electric field force had a particular impact on the diameter and yield of PEI and PEN fibers. Changes in rotational speed had negligible effects on both PEI and PEN fibers. Additionally, due to their different molecular structures, PEI and PEN, which have different chain lengths, exhibit varied spinning trends. This study established a mesoscopic dynamic foundation for producing high-performance ultrafine fibers and provided theoretical guidance for future electrospinning experiments. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

17 pages, 26255 KB

Open AccessArticle

The Influence of the Amount of Technological Waste on the Performance Properties of Fibrous Polymer Composites

by Jozef Dobránsky, Miroslav Gombár and Patrik Fejko

J. Compos. Sci. 2024, 8(11), 470; https://doi.org/10.3390/jcs8110470 - 13 Nov 2024

Viewed by 1121

Abstract

The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which [...] Read more.

The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which belongs to a group of high-tech polymers, was chosen as the analyzed material. In accordance with the set goals, the rheological, mechanical, and structural properties of the material were evaluated using ANOVA analysis in the experimental part of the work, depending on the mass ratio of the recycled material added to the virgin material. The influence of the proportion of recycled material on the lifetime of moldings by the method of their exposure at an elevated temperature for a defined time was also assessed. During the research, it was found that at a concentration of up to 40 wt. % of recyclate, its mechanical properties do not change significantly. At a concentration of 50 wt. %, there is a rapid decrease in mechanical properties. In the long term, it can also be said that the addition of recyclate significantly affects the service life of the components. No significant changes in morphology were observed during the analysis of structural properties. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

23 pages, 10593 KB

Open AccessArticle

Mechanical, Durability, and Microstructure Characterization of Pervious Concrete Incorporating Polypropylene Fibers and Fly Ash/Silica Fume

by Hassan Bilal, Xiaojian Gao, Liborio Cavaleri, Alamgir Khan and Miao Ren

J. Compos. Sci. 2024, 8(11), 456; https://doi.org/10.3390/jcs8110456 - 3 Nov 2024

Cited by 10 | Viewed by 3538

Abstract

Pervious concrete, because of its high porosity, is a suitable material for reducing the effects of water precipitations and is primarily utilized in road pavements. In this study, the effects of binder-to-aggregate (B/A) ratios, as well as mineral admixtures with and without polypropylene [...] Read more.

Pervious concrete, because of its high porosity, is a suitable material for reducing the effects of water precipitations and is primarily utilized in road pavements. In this study, the effects of binder-to-aggregate (B/A) ratios, as well as mineral admixtures with and without polypropylene fibers (PPFs) (0.2% by volume), including fly ash (FA) or silica fume (SF) (10% by substitution of cement), on the mechanical properties and durability of pervious concrete were experimentally observed. The experimental campaign included the following tests: permeability, porosity, compressive strength, splitting tensile strength, and flexural strength tests. The durability performance was evaluated by observing freeze–thaw cycles and abrasion resistance after 28 d curing. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA-DTA), and scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) were employed to investigate the phase composition and microstructure. The results revealed that, for an assigned B/A ratio identified as optimal, the incorporation of mineral admixtures and fibers mutually compensated for their respective negative effects, resulting in the effective enhancement of both mechanical/microstructural characteristics and durability properties. In general, pervious concrete developed with fly ash or silica fume achieved higher compressive strength (>35 MPA) and permeability of 4 mm/s, whereas the binary combination of fly ash or silica fume with 0.2% PPFs yielded a flexural strength greater than 6 MPA and a permeability of 6 mm/s. Silica fume-based pervious concrete exhibited excellent performance in terms of freeze–thaw (F-T) cycling and abrasion resistance, followed by fiber-reinforced pervious concrete, except fly ash-based pervious concrete. Microstructural analysis showed that the inclusion of fly ash or silica fume reduced the harmful capillary pores and refined the pore enlargement caused by PPFs in the cement interface matrix through micro-filling and a pozzolanic reaction, leading to improved mechanical and durability characteristics of pervious concrete. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

32 pages, 14430 KB

Open AccessArticle

Mechanical Properties of Natural Jute Fiber-Reinforced Geopolymer Concrete: Effects of Various Lengths and Volume Fractions

by Abdulrhman Dhaif Allah Abdo Mohammed, Wang Ronghui and Ghasan Fahim Huseien

J. Compos. Sci. 2024, 8(11), 450; https://doi.org/10.3390/jcs8110450 - 1 Nov 2024

Cited by 3 | Viewed by 2804

Abstract

Enhancing the fracture strength and ductility of concrete through the incorporation of various types of synthetic and natural fibers with varying textures and contents remains challenging. Natural fibers, being versatile and eco-friendly construction materials, can be an excellent alternative to synthetic fibers. However, [...] Read more.

Enhancing the fracture strength and ductility of concrete through the incorporation of various types of synthetic and natural fibers with varying textures and contents remains challenging. Natural fibers, being versatile and eco-friendly construction materials, can be an excellent alternative to synthetic fibers. However, studies on natural fiber-reinforced (especially through the incorporation of jute fibers) novel composites like geopolymer binders remain deficient. Thus, the effects of various lengths (15, 25 and 35 mm) and volume contents (0.10, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70%) of natural jute fibers on the mechanical performance of fiber-reinforced geopolymer concrete were studied. The results revealed that jute fiber reinforcement remarkably affected the workability, compressive strength, fracture strengths, water absorption and microstructure properties of the proposed geopolymer concretes. Increasing the fiber length and volume fractions in the geopolymer matrix lowered the slump values and workability and increased the compressive strength. The specimen prepared with a fiber length of 35 mm and volume fractions of 0.70% displayed the lowest slump value (28 mm) and highest compressive strength (31.5 MPa) at 28 days. In addition, the specimens made with fiber volume fractions of 0.10, 0.20, 0.30, and 0.40% showed a significant improvement in the splitting tensile and flexural strengths. However, increasing the volume of the jute fibers up to 0.50% led to a slight drop in the fracture strength of the geopolymers. The specimens prepared with a length of 25 mm and a volume of 0.40% achieved the highest enhancement of splitting tensile strength (18.7%) and flexural strength (29.1%) at 28 days. In short, sustainable geopolymer concrete with high fracture performance can be obtained by incorporating natural jute fibers, leading to practical applications in the construction sector. The proposed green concrete may enable a reduction in solid waste, thus promoting a more sustainable concrete industry. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

19 pages, 51632 KB

Open AccessArticle

Three-Dimensional Printing Limitations of Polymers Reinforced with Continuous Stainless Steel Fibres and Curvature Stiffness

by Alison J. Clarke, Andrew N. Dickson, Vladimir Milosavljević and Denis P. Dowling

J. Compos. Sci. 2024, 8(10), 410; https://doi.org/10.3390/jcs8100410 - 6 Oct 2024

Cited by 1 | Viewed by 2185

Abstract

This study investigates the printability limitations of 3D-printed continuous 316L stainless steel fibre-reinforced polymer composites obtained using the Materials Extrusion (MEX) technique. The objective was to better understand the geometric printing limitations of composites fabricated using continuous steel fibres, based on a combination [...] Read more.

This study investigates the printability limitations of 3D-printed continuous 316L stainless steel fibre-reinforced polymer composites obtained using the Materials Extrusion (MEX) technique. The objective was to better understand the geometric printing limitations of composites fabricated using continuous steel fibres, based on a combination of bending stiffness testing and piezoresistive property studies. The 0.5 mm composite filaments used in this study were obtained by co-extruding polylactic acid (PLA), with a 316 L stainless steel fibre (SSF) bundle. The composite printability limitations were evaluated by the printing of a series of ’teardrop’ shaped geometries with angles in the range from 5° to 90° and radii between 2 and 20 mm. The morphology and dimensional measurements of the resulting PLA-SSF prints were evaluated using

μ

CT scanning, optical microscopy, and calliper measurements. Sample sets were compared and statistically examined to evaluate the repeatability, turning ability, and geometrical print limitations, along with dimensional fluctuations between designed and as-printed structures. Comparisons of the curvature bending stiffness were made with the PLA-only polymer and with 3D-printed nylon-reinforced short and long carbon fibre composites. It was demonstrated that the stainless steel composites exhibited an increase in bending stiffness at smaller radii. The change in piezoresistance response of the PLA-SSF with load applied during the curvature bending stiffness testing demonstrated that the 3D-printed composites may have the potential for use as structural health monitoring sensors. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

20 pages, 7405 KB

Open AccessArticle

Stress Analysis of Glass Fiber-Reinforced Polymer Lap Joints with Modified Adhesives at Various Temperatures

by Hasan Caglar, Sridhar Idapalapati, Mohit Sharma and Chian Kerm Sin

J. Compos. Sci. 2024, 8(10), 406; https://doi.org/10.3390/jcs8100406 - 4 Oct 2024

Viewed by 1863

Abstract

This study examines stress distributions in adhesive joints under various loading and temperature conditions. Finite element analysis (FEA) was employed to compute the peel and shear stresses at the adhesive interface and bondline mid-section. Dependency analysis shows that mid-section peel stress significantly impacts [...] Read more.

This study examines stress distributions in adhesive joints under various loading and temperature conditions. Finite element analysis (FEA) was employed to compute the peel and shear stresses at the adhesive interface and bondline mid-section. Dependency analysis shows that mid-section peel stress significantly impacts the experimental shear strength of SLJs more than shear stress. This insight highlights the need to carefully analyze peel stress and bending moment factors. The analytical solutions proposed by Goland and Reissner were analyzed with modifications by Hart-Smith and Zhao. Hart-Smith’s approach performed more effectively, especially when the adhesive layer thickness (t_a) was 0.5 mm and the overlap length to thickness ratio (c/t_a) was ≥20. FEA revealed stress distributions at the adhesive/adherend interface and bondline mid-section. DP490 adhesive joints exhibited lower stresses than EA9696. Temperature variations significantly affected joint behavior, particularly above the adhesive’s glass transition temperature (T_g). Both EA9696 and DP490 adhesive joints displayed distinct responses to stress and temperature changes. The parabolic and biquadratic solutions for functionally graded adhesive (FGA) joints were compared. The biquadratic solution consistently yielded higher shear and peel stress values, with an increase ranging from 15% to 71% compared to the parabolic solution at various temperatures because of the larger gradient of the Young’s modulus distribution near the overlap ends. The ratio of peak peel stress to peak shear stress suggests that selecting an adhesive with a superior peel strength or primarily reducing the peak peel stress by functionally grading is advisable, particularly if the adhesive is brittle. The comparison of stress distributions emphasizes the importance of selecting adhesives based on stress type, temperature, and solution methods in optimizing adhesive bonding applications. These findings provide valuable insights for thermomechanical applications where thermal stimuli may be used for controlled debonding. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

14 pages, 4235 KB

Open AccessArticle

Recycled Low Density Polyethylene Reinforced with Deverra tortuosa Vegetable Fibers

by Tahani Zorgui, Hibal Ahmad, Mehrez Romdhane and Denis Rodrigue

J. Compos. Sci. 2024, 8(10), 394; https://doi.org/10.3390/jcs8100394 - 1 Oct 2024

Cited by 1 | Viewed by 1942

Abstract

In this work, natural fibers extracted from the medicinal aromatic plant Deverra tortuosa, with different sizes (S1 = 2 mm and S2 = 500 μm), were incorporated into recycled low density polyethylene (rLDPE) to produce sustainable biocomposites. Compounding was performed with different [...] Read more.

In this work, natural fibers extracted from the medicinal aromatic plant Deverra tortuosa, with different sizes (S1 = 2 mm and S2 = 500 μm), were incorporated into recycled low density polyethylene (rLDPE) to produce sustainable biocomposites. Compounding was performed with different fiber concentrations (0 to 30% wt.) via twin-screw extrusion followed by injection molding. Based on the samples obtained, a comprehensive series of characterization was conducted, encompassing morphological and mechanical (flexural, tensile, hardness, and impact) properties. Additionally, thermal properties were assessed via differential scanning calorimetry (DSC), while Fourier transform infrared spectroscopy (FTIR) was used to elucidate potential chemical interactions and changes with processing. Across the range of conditions investigated, substantial improvements were observed in the rLDPE properties, in particular for the tensile modulus (23% for S1 and 104% for S2), flexural modulus (47% for S1 and 61% for S2), and flexural strength (31% for S1 and 65% for S2). Nevertheless, the tensile strength decreased (15% for S1 and 46% for S2) due to poor fiber–matrix interfacial adhesion. These preliminary results can be used for further development in sustainable packaging materials. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Graphical abstract

Review

Jump to: Research

22 pages, 3198 KB

Open AccessReview

High-Temperature Polyimide Composites—A Review on Polyimide Types, Manufacturing, and Mechanical and Thermal Behavior

by Vahid Daghigh, Hamid Daghigh and Roger Harrison

J. Compos. Sci. 2025, 9(10), 526; https://doi.org/10.3390/jcs9100526 - 1 Oct 2025

Viewed by 524

Abstract

Polyimide composites represent a class of advanced materials with remarkable mechanical robustness and thermal stability, making them highly suitable for applications in extreme environments. Their unique ability to maintain performance under high temperatures and corrosive conditions, combined with a favorable strength-to-weight ratio, positions [...] Read more.

Polyimide composites represent a class of advanced materials with remarkable mechanical robustness and thermal stability, making them highly suitable for applications in extreme environments. Their unique ability to maintain performance under high temperatures and corrosive conditions, combined with a favorable strength-to-weight ratio, positions them as critical components in aerospace, electronics, and automotive systems. Several leading aerospace and electronics corporations have made significant investments in incorporating polyimide composites into their products, indicating the material’s transformative potential. This review paper provides an overview of mechanical and thermal behaviors of polyimide composites, summarizing recent developments and research trends. It examines the influence of various reinforcements, processing techniques, and composite architectures on material performance under mechanical loading and thermal stress. The paper synthesizes findings from experimental studies and modeling efforts to highlight the critical factors affecting strength, durability, and thermal stability. Discussion and recommendations regarding applications in aerospace, electronics, and other high-temperature environments are provided, emphasizing the challenges and opportunities presented by these advanced materials. This review adopts a broad scope to reflect the interdisciplinary nature of polyimide research. Due to gaps in literature, this work aims to provide a foundational overview that supports future, more specialized investigations. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

52 pages, 4685 KB

Open AccessReview

Epoxy Resins and Their Hardeners Based on Phosphorus–Nitrogen Compounds

by Pavel Yudaev, Bakary Tamboura, Anastasia Konstantinova, Heeralal Vignesh Babu and Krishnamurthi Muralidharan

J. Compos. Sci. 2025, 9(6), 277; https://doi.org/10.3390/jcs9060277 - 29 May 2025

Cited by 2 | Viewed by 1801

Abstract

This review examines the fire-retardant properties of compositions that incorporate various classes of phosphorus–nitrogen compounds. Specifically, it focuses on nitrogen-containing derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phosphinates, phosphorus–nitrogen salts, and aryloxycyclophosphazenes. The findings indicate that these classes of fire retardants enhance the limiting oxygen index, decrease [...] Read more.

This review examines the fire-retardant properties of compositions that incorporate various classes of phosphorus–nitrogen compounds. Specifically, it focuses on nitrogen-containing derivatives of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, phosphinates, phosphorus–nitrogen salts, and aryloxycyclophosphazenes. The findings indicate that these classes of fire retardants enhance the limiting oxygen index, decrease heat and smoke emission indices in epoxy compositions, and facilitate the creation of self-extinguishing materials. Notably, aryloxycyclophosphazenes with reactive functional groups emerge as the most effective fire retardants, particularly in terms of their impact on the mechanical properties of epoxy compositions and compatibility with epoxy resin. This review would be a valuable resource for engineers, chemical engineers, materials scientists, and researchers engaged in the development of non-combustible polymer composites and organoelement compounds. Full article

(This article belongs to the Special Issue Polymer Composites and Fibers, 3rd Edition)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Polymer Composites and Fibers, 3rd Edition

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (22 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI