To tackle the challenge of manufacturing highly filled composite materials via melt compounding and injection molding, the authors proposed a novel approach based on Diels-Alder (DA) chemistry. Polycaprolactone oligomers (PCLolig, Mw = 2000 g/mol) were firstly crosslinked by DA bonds, and then the resultant network PCLolig-DA was also connected to maleimide functionalized Al2O3 particles (Al2O3-M)

In order to prepare the high-performance electromagnetic interference (EMI) shielding materials to cope with the increasingly serious electromagnetic (EM) radiation pollution situation, in this work, epoxy/Ag nanowire/thermal annealed graphene aerogel composites (EP/AgNW/TAGA) with three-dimensional (3D) bicontinuous conductive skeleton are prepared through a vacuum-assisted impregnation method. By

A bulk modification method is developed in this paper to achieve a new nanoparticle-reinforced silicone rubber composite with high strength and strong adhesion. Different from existing modification methods, an adhesion promoter is added in order to improve the adhesive property in addition to the surface modified silica nanoparticle. Furthermore, the adhesion promoter also exhibits an excellent compatibility

Multilayered aramid nanofiber/silver nanowire (ANF/AgNW) films using AgNW as internal conductive layers and ANF as outer protective layers were fabricated via a multiple filtration layer-by-layer process and subsequent hot-pressing. The electromagnetic interference (EMI) shielding and mechanical properties of the multilayered ANF/AgNW films were significantly improved through hydrogen bonding between

Flax fibre mats are promising and versatile biosourced reinforcements that can be used in composite parts obtained using various processing routes. To optimise their impregnation and the end-use properties of composites, it is crucial to better understand the process-induced evolution of their microstructure and their permeability. In this study, flax fibre mats were subjected to in situ X-ray microtomography

To explore the effects of thermal shock cycles on ZrC-C composites, their microstructure, coefficient of thermal expansion (CTE), compressive strength and internal friction behavior after different thermal shock cycles were studied. As the thermal shock cycle between 1500 ℃ and room temperature increased from 0 to 30, the CTE of the ZrC-C composites with the ZrC/PyC (Pyrolytic carbon) weight ratio

In this paper, a shape-stabilized and flexible phase change film is prepared based on polyethylene glycol (PEG), which is stabilized by the co-operation of cellulose nanofibers (CNF) and expanded graphite (EG). The thermal conductivity of the prepared film is enhanced by boron nitride (BN). The results show that the thermal conductivity of the prepared film can reach to 10.83 W/(m·K) along the in-plane

Primary load-bearing composite structures require high laminate quality. This is achieved by autoclave prepreg processing where high external pressures enhance consolidation. As a result, parts of simple geometry can be manufactured with void contents less than 1%. However, defects such as wrinkles and voids are typically found within more complex structures. This research investigates defect formation

The present work focuses on the modelling of transient incompressible two phase flow during vacuum assisted resin transfer molding (VARTM) in the presence of high permeability media (HPM). A novel depth-averaged technique coupled with level set has been introduced to capture the spatio-temporal variation of preform compaction, permeability, transverse seepage flow from the HPM to the porous preform

In this work, we have established a multiscale model to accurately calculate the effective thermal conductivity of the composite of graphene and polyamide-6 (PA-6) and use this model to search for the optimal orientation distribution of the graphene flakes to maximize the composite thermal conductivity. Compared with the direct results of large-scale molecular dynamics simulations on the validation

A new experimental technique is proposed to measure the pressure gradient in corner laminates with the aim of guiding manufacturing practices that can produce composites laminates to the desired thickness. A pressure mapping sensor was placed between a metal mould tool and a silicone sheet that acts as an idealised composite part. The compaction pressure loss in internal corners and rise in external

The heterogeneous and anisotropic nature of fiber reinforced polymers induces the initiation of various damage mechanisms at different scales. Even though full-field surface measurements may successfully track damage development, such approaches do not provide insights into the material bulk. The present work aims at comparing surface and bulk full-field measurements (via Digital Image/Volume Correlation)

The Wet Compression Moulding (WCM) process is a recently re-introduced production technique increasingly adopted in industry, most commonly in the automotive sector, for high volume production of structural reinforced plastics components. To date, process design parameters have been established through experiences gained by technologists. To develop an understanding of the influence of process and

Thermoplastic braid-trusion is a composite manufacturing process that combines braiding and pultrusion of hybrid yarns containing reinforcement and polymer fibers. During pultrusion, the melting of the polymer fibers leads to complex morphological changes at the macro, meso and micro scales. We introduce here a multiscale numerical simulation methodology to model this process. In this methodology,

In-plane permeability of small area (100 × 50 mm) alumina fiber woven fabrics grafted with aligned carbon nanotubes (CNT) was quantified by placing them in series with a glass mat of known permeability during a flow experiment. The methodology was first validated on a reference woven textile. Permeability values matched those obtained by a direct method within a margin of ±15%. Permeabilities of radial-aligned

Traditional modifiers with low-molecular-weight often result in a rigid interface between reinforcing fibers and matrix. This study built a flexible interphase for a linear low-density polyethylene and bamboo fiber (LLDPE/BF) composite by synthesizing a silane-based flexible macromolecular modifier (γ-APS-PAEE). FTIR analysis indicated that γ-APS-PAEE bridged BF and LLDPE by chemical bonding and good

Influences of fillers [including multi-walled carbon nanotubes (MWCNTs), SiC nanowires, methyl-polyhedral oligomeric silsesquioxanes (methyl-POSS) and boron phenolic resin] on the characteristics of porous structure in char layers of ethylene propylene diene monomer (EPDM) composites were studied using experimental solid rocket motor (SRM). Comparing to basic formulation (Porosity: 78.25%), char layers

Liquid composite molding (LCM) simulations for processes such as resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM) face serious challenges while modelling resin flow through dual scale fabrics such as bi-directional (BD) (stitched or woven) fabrics and triaxial fabrics as it requires characterization of two permeability values: inter-tow gap or bulk permeability and tow

This paper presents an experimental investigation of the multi-scale toughening mechanisms for improving the interlaminar fracture toughness, low-velocity impact damage resistance and compression-after-impact (CAI) strength of continuous carbon fibre-epoxy composite laminates using carbon nano- and micro-fillers spanning the nanometer to millimeter length scales. The fillers used in the epoxy matrix

Nano-fillers have attracted a large amount of attention in enhancing the mechanical properties of polymer bonded explosive (PBX), due to the strong interfacial interactions. However, the addition of inert components reduces the energy output and makes the processing, recycling and re-utilization of energetic composites quite unfavorable. To improve the mechanical properties while maintaining detonation

Polymer-based thermal conductivity composites composed with nanoscale fillers are promising thermal conductors to dissipate accumulated heat of integrated circuits in electronic devices, while interfacial thermal resistance (ITR) and disordered conductive pathways caused by the size effect of fillers limit their heat transfer performance. Herein, gravitational-driven ice-templated oriental arrangement

This research employed an integrated design method with 3D printing to endow a base polymer for unique mechanical properties, i.e., enhanced effective elastic modulus or negative Poisson’s ratio using continuous carbon fibres (CCF). A multidisciplinary technique integrating homogenisation-based topology optimisation and fibre placement methodology is developed for 3D printing set-up with a fused filament

Composites with hollow structures have received attention worldwide for microwave absorption because of their light weight, high strength and unique wave absorption properties. In this study, the complex permittivity and complex permeability were determined for epoxy resin (EP) with different carbonyl iron particle (CIP) contents. These results were used to design a series of CIP/EP composites with

There are two types of flow mechanism in prepreg processing: shear flow, in which resin and fibers flow together, and percolation flow, in which resin flows out of the gaps between fibers. In this study, we experimentally evaluated how these flow mechanisms change during cure including the gelation stage. Results of compression tests at various initial degree of cure at the start of compression showed

Matrix cracking of carbon fibre reinforced polymer composites at super cold temperatures, such as liquid hydrogen temperature, is a major issue for lightweight fuel storage, because the microcracks induced by the high thermal residual stresses in the matrix can cause fuel leaks and degrade the structural integrity of the storage vessel. Herein, we report a new method of toughening carbon fibre composites

Composite laminate thickness tapering is essential for weight efficient structures. This is achieved by terminating specific plies, but these can in turn act as sites for delamination initiation. One area of importance is the spacing between adjacent ply drops, which can have a significant impact on the delamination stress. In this work, a novel tape scarfing method that applies a tapered profile to

The effect of inter-ply sliding was investigated for multi-ply Non-Crimp Fabric (NCF) preforms during the Double Diaphragm Forming (DDF) process. A Finite Element (FE) model was employed to investigate the influence of the ply layup sequence and the coefficient of friction between fabric-fabric and fabric-diaphragm interfaces. Simulation results indicate that in-plane fibre compression, caused by dissimilar

This study investigates the shape memory behavior of epoxy-based pultruded flat laminates reinforced with unidirectional glass fibers. To evaluate the shape memory performance of the composite material, a series of tests by bending flat specimens to the shape programming angle has been conducted. The shape fixity and shape recovery ratios for the pultruded composite specimens with 90° fiber orientation

Applying acoustic emission method to understand the damage and failure mechanism of hybrid composites is challenge for industry. For this study, nine types of carbon/glass fiber-reinforced hybrid laminate composite specimens with different structure and indentation were subjected to tensile experiments. The AE signals collected during the tensile process were post-processed using cluster analysis based

A copolymer of P(S-co-BCB-co-GMA) synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization was coated on the surface of poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibres, followed by grafting 2, 2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (AHHFP) to obtain 6F-PBO@P-GMA fibres. The corresponding 6F-PBO@P-GMA fibres/modified cyanate ester wave-transparent laminated

In order to study the axial compression behavior of short columns confined with carbon fiber reinforced polymers (CFRP), 21 specimens were tested under monotonic loading. Four failure modes were classified based on the test results which were adhesive layer failure, compression failure, buckling failure and local buckling failure. With the improvement of external reinforcement effect, the failure mode

In this work, a novel type of phosphorus containing hyperbranched polysiloxane (P-HBPSi) was synthesized by sol–gel method, and then utilized to functionalize graphene oxide (P-HBPSi@GO). The P-HBPSi@GO hybrids were mixed with TPU by melt compounding. The SEM observation revealed that the P-HBPSi@GO dispersed homogeneously in the TPU matrix with good compatibility. The TPU/P-HBPSi@GO-2.0 maintained

The Automated Fibre Placement (AFP) process has gained traction as an efficient manufacturing method for large and complex composite structures. An AFP machine uses a computer-controlled arm with a head at the end capable of constant placement of uncured pre-impregnated carbon fibre tows grouped together to form bands. While AFP offers benefits through automation, certain defects inherent to the manufacturing

Rubbers with dynamic covalent bonds generally require external stimuli to trigger the healing process, e.g. high temperature, which caused inconvenience to utilize. In contrast, rubbers based on noncovalent supramolecular networks can be spontaneously repaired under mild conditions, but usually exhibit kPa level on the mechanical properties. In this paper, a rapid self-healing composite film with considerable

A MX/CF/Epoxy composite with a 3D network structure was prepared through a one-step impregnation method. Compared with the simple doping of MXene into the polymer matrix, the 3D structure greatly reduces the amount of absorbing filler while improving the microwave absorbing performance of epoxy resin, which realizes the economical and efficient use of absorbing agents. The MX/CF/Epoxy composite has

The translaminar fracture toughness and its dependence on the environmental condition are key considerations in designing aerospace-grade composites with a high damage tolerance to severe service conditions in terms of temperature and moisture. The present work characterises and models the hygrothermal effects on the translaminar fracture toughness of an interlaminar toughened aerospace carbon/epoxy

Being the key process of a promising scalable production method, mechanical peeling is often used to construct high-quality van der Waals (vdW) heterostructures. By combining molecular dynamics (MD) studies and theoretical analysis, the investigation of the process of peeling heterostructures at different angles is reported. Taking vdW interaction into account, we present a theory that considers the

This paper investigates the effect of Z-pin insertion angles (60°, 75° and 90°) on low-velocity impact mechanical response and damage mechanism for cross-ply and quasi-isotropic layups. The laminates were impacted with 25 J, 40 J and 60 J to obtain different mechanical response and damage status (permanent dent, delamination and backside damage). Experimental results demonstrate that the impact resistance

Increasing interfacial shear strength (IFSS) has been observed to improve fracture toughness within carbon fiber/epoxy laminates. However, a direct correlation between IFSS of carbon fiber surface treatments and open-hole compressive (OHC) strength has never been established. Here the effects of systematically altering electrochemical oxidation surface treatments (0, 2 and 3.4 Amps) and sizing deposition

Hyperbranched fluorine and epoxy containing PBO precursor (epoxy-preFHBPBO) was synthesized and utilized as interface compatibilizer to synchronously improve the mechanical and dielectric properties of poly(p-phenylene-2, 6-benzobisoxazole) (PBO) fibres reinforced bisphenol A dicyanate ester (BADCy) resins (PBO fibres/FHBPBO-co-BADCy) laminated composites. 1H NMR, 13C NMR, and FTIR analyses confirmed

Owing to the flexible and controllable characteristics, the magnetic composite film becomes an ideal option for future portable, efficient and multifunctional magnetic soft actuators. Here, an anisotropic magneto-sensitive elastomer film (MSEF) composite based on polydimethylsiloxane (PDMS) and high concentration of carbonyl iron particles (CIPs) was developed. The off-plane design of CIP structures

Fused filament fabrication (FFF) technology is one of the most widely used 3D printing methods. Due to the high orientation of the fillers caused by printing, the development of thermally conductive composites suitable for FFF has broad prospects. Although there have been some studies on the effect of h-BN content on the thermal conductivity of composites, there are very few studies on the effect of

Polylactic acid (PLA) with eco-friendliness exhibits extensive potential applications. In order to enhance fire-resistance of PLA, this manuscript reports the preparation of boron-containing ammonium polyphosphate (B-APP) using 3-aminophenyl boronic acid and ammonium polyphosphate through ion exchange reaction, and incorporated into PLA matrix. The limiting oxygen index (LOI) of PLA-5% B-APP was increased

In this study, the effect of rapid laser heating, which is typical during laser-assisted fiber placement (LAFP), on the micro- and meso- structure of the thermoplastic tape was investigated. Thermoplastic tapes were heated above the melting temperature with different heated lengths (30 and 80 mm and heating times (0.2 and 0.8 s) in a dedicated experimental setup. In-situ and ex-situ characterization

Layered zinc N, N’-piperazine (bismethylene phosphonate) functionalizing reduced graphene oxide (rGO@ZnPB) was prepared via in-situ method for the reduction of fire hazards of epoxy resin (EP), as well as the improvement on its thermal and mechanical properties. The results reveal a better flame retardancy of rGO@ZnPB than either rGO or ZnPB at the same loading level for EP. Remarkably, EP with 5.0

The location of isolated SiO2 nanoparticles (NPs) grafted with silane or poly(methyl methacrylate) (PMMA) brushes and their agglomerates in a phase-separated PMMA/poly(styrene-acrylonitrile) (SAN) blend is investigated. The isolated NPs can be selectively distributed at the interface of PMMA/SAN blend, while their agglomerates are selectively distributed in one phase of blend matrix. Without the interference

The present work focuses on the characterization of the in-plane and out-of-plane behavior of a three-dimensional angle-interlock woven composite. In-plane tensile and compression tests, short beam shear tests and through-the-thickness compressive tests were carried out to assess the mechanical behavior of the composite material. The results are presented in terms of stress–strain responses, elastic

Carbon black (CB) is a principal filler in rubber industry due to its excellent reinforcing effect and low-cost. It is of significant importance but challenging to modify the inert CB for addressing the dilemma of increased energy loss raised by the addition of CB. In this work, we reported the functionalization of CB through redox polymerization of rhodanine on its surface, and utilized the modified

Lightweight and multifunctional thermoconductive electromagnetic interference (EMI) shielding nanocomposites with excellent EMI shielding performance and heat dissipation are in high demand for the development of the next generation of highly integrated electronic devices. Herein, a scalable fabrication method for multifunctional nanocomposites with tunable thermal conductivity and superior EMI shielding

Ultrasonic welding (USW) provides a cost-efficient method for joining fiber reinforced thermoplastic composite (FRTP) which is increasingly used in various industries as a kind of emerging lightweight material. As a result of the distinct 3D fibrous and porous network structures of FRTP together with the ultrafast and multiphysical features of USW, a great deal of interest has been generated to study