Properties Of Resulting Composites Research Articles

Fabrication of microfibrillated cellulose reinforced polypropylene composites assisted by a synergistic strategy of pre‐quaternization and paper‐making process

AbstractTo tackle the ease of aggregation issue of highly hydrophilic microfibrillated cellulose (MFC) in polypropylene (PP) that thus results in an undesired reinforcing effect, this work developed an effective and industrially feasible strategy combining pre‐quaternization of pulp fibers with paper‐making process to fabricate PP/MFC composite with enhanced performance. Effects of MFC consistency, maleic anhydride grafted polypropylene (MAPP) content, and plasma treatment of chopped PP fibers on the mechanical and thermal properties of resultant composites were systematically investigated. The surface‐quaternized MFC obtained by a low‐consistency refiner (L‐MFC) exhibited a higher aspect ratio and degree of fibrillation than the corresponding surface‐quaternized MFC obtained by a high‐consistency one (H‐MFC). It was found that there existed a synergistic effect between pre‐quaternization and the paper‐making process in promoting the dispersion of MFC in PP. As compared with L‐MFC, a higher reinforcing efficiency on PP was achieved for H‐MFC, which was because the former one was more prone to form the fibril aggregates in the PP matrix. Due to both the entangled network of MFC and its nucleation effect on PP, the heat deflection temperature (HDT) of resulting composites was largely increased up to 159.9°C, an increase of 68.7°C with respect to that of PP.Highlights The H‐MFC yielded a superior reinforcement on PP than L‐MFC. The optimum mechanical properties of PP/composites were achieved at 15% MAPP. Interfacial bonding between PP and H‐MFC was enhanced by plasma treatment. An increase in Tc of the PP matrix was noted for PP/MFC. A maximum increase of 159.9°C in HDT was achieved for PP/MFC.

Preparation and characterisation of zirconia/hydroxyapatite bioactive composites as potential dental implants

In dental implants, zirconia is well-known as a crown material due to its excellent acid and base resistances and appearance close to natural teeth. In addition, its extraordinary mechanical properties render zirconia to be a potential candidate as an implant component of a whole implanted tooth, if its biocompatibility can be improved to promote adhesion to natural hard tissues. This study aims to enhance the bioactivity of zirconia with the aim of improving its integration with gum bone. Hydroxyapatite is the major component of natural bone and is thus selected as the modifier to improve the bioactivity of zirconia. A series of zirconia/hydroxyapatite composites with varied compositions were prepared under different conditions in order to find the optimal composites for the target application. Various analytical technologies and mechanical tests are employed to characterise the structure and properties of resultant composites. Results show that the component ratio and sintering temperature have a significant influence on the composite properties. An increase in hydroxyapatite component tends to enhance bioactivity but decline mechanical strength. Composites containing 10 wt% of hydroxyapatite maintain sufficient mechanical strength under the optimal sintering conditions whilst possessing excellent bioactivity, demonstrating that hydroxyapatite-modified zirconia has the potential as dental implant materials. Sintering results suggest that mechanical strength is obtained at 1400 °C for 2 h for the composite containing 10 wt% of hydroxyapatite.

The Effect of Synthetic Zeolite on the Curing Process and the Properties of the Natural Rubber-Based Composites.

Zeolites, known for their unique structural and catalytic properties, are added to the natural rubber matrix to investigate their influence on the vulcanization process and the resultant properties of composites. The natural rubber-based composites were masticated with 4A synthetic zeolite (0, 5, 10, 15, 20, and 30 phr). The curing of the rubber compounds was monitored on a moving die rheometer at 150 °C. The isothermal DSC method was also used to study the curing process at 150 °C, 160 °C, and 170 °C. Based on the obtained results, it is assumed that there is an interaction between the components of the curing system and the surface of the zeolite particle, and that is why the vulcanization reaction starts earlier with an increase in zeolite in the rubber mixture. This underscores the significant role of zeolite in accelerating the curing reaction of natural rubber-based compounds. The composites were vulcanized in a press at 150 °C for 15 min. The chemical structure was analyzed using FTIR, and the sample morphology was examined using SEM. The degree of swelling in toluene and distilled water was determined. The tensile strength values, modulus of elasticity at 100% and 300% elongation, and elongation at break were measured using a universal testing machine. Hardness was assessed according to the Shore A scale. With a small addition of zeolite (up to 10 phr), there is no significant change in the tensile strength values. However, adding a considerable amount of zeolite to a natural rubber matrix results in a deterioration of the tested mechanical properties. It can be assumed that with large proportions of zeolite 4A MS in the composites, the mechanical properties deteriorated due to increased porosity. The amount of added zeolite affects the initial stages of thermal decomposition of the examined samples and the rest after the analysis at a temperature of 500 °C.

Improved photocatalytic activity of graphene oxide modified Ag-TiO2 for degradation of piroxicam-20 and dehydrogenation of methanol under light irradiation

BackgroundGraphene oxide (GO), an atomic sheet structure made of sp2-bonded carbon atoms with superior optoelectronic, and catalytic properties, has attracted much interest. Incorporating a carbon-rich material, onto metal-loaded TiO2 is reported to increase the photocatalytic properties of resultant composites. MethodsThis research aimed at the deposition of different amounts (1–5 wt.%) of GO using the ultrasonication method on bare TiO2 and Ag (3 wt.%)-TiO2 (AT3) and studied their influence on piroxicam-20 degradation under visible light and methanol dehydrogenation under UV light. The prepared composites' structural, optical, and morphological properties were characterized using XRD, DRS, HR-TEM, FE-SEM, and XPS. Significant findingsHRTEM analysis confirmed the existence of GO layers and spherical-shaped Ag nanoparticles deposited over the TiO2 surface. GO(5 wt.%)@Ag(3 wt.%)-TiO2 (G5@AT3) displayed better photodegradation efficiency (78 %) (k = 0.0082 min−1) under 120 min, and GO(1 wt.%)@Ag(3 wt.%)-TiO2 (G1@AT3) composite produced higher amount (427 mmol) of H2 from photocatalytic dehydrogenation of CH3OH under 5 h relative to TiO2 (2 mmol), AT3 (166 mmol) and GO(5 wt.%)@TiO2 composite (GT5) (11 mmol). HRMS analysis was performed to identify the piroxicam-20 degradation intermediates. Thus, this research provides a proactive strategy highlighting the cooperative effect of Ag and GO loading to improve the photocatalytic efficiency of TiO2 photocatalyst using both UV–visible light irradiation.

Roles of different organic-inorganic hybrid interfaces in enhancing the mechanical properties of continuous basalt fiber/epoxy composites

ABSTRACT In order to enhance the interfacial adhesion between continuous basalt fibers (CBFs) and epoxy (EP) matrix and the mechanical properties of resultant composites, the organic – inorganic hybrid compatibilization layer (OIHCL) composed of flexible 1,6-hexanediol diglycidyl ether (HDE) chains and rigid nano-silica (SiO2) is grafted on CBFs surface. With increasing the SiO2 content in the OIHCL, the structure and composition of the OIHCL change from a single layer composed of a well-dispersed SiO2 phase and continuous HDE phase to a double layer composed of an HDE/SiO2 inner-layer and aggregated SiO2 outer-layer. And, the effects of different OIHCLs on the mechanical performances of resultant composite are studied in details. The results show that the single-layer OIHCL exhibits stronger reinforcing effects in the interfacial shear strength (IFSS), tensile strength, and flexural strength of resultant composite. For example, the IFSS, tensile strength, and flexural strength of the CBFs-g-12.5%-(HDE/SiO2)/EP composite can reach 47.1 MPa, 466.1 MPa, and 660.5 MPa, respectively. Furthermore, the impact strength of the CBF/EP composites can be effectively enhanced by only grafting a flexible HDE layer on CBF surfaces. Finally, the aggregated SiO2 derived from the outer-layer of double-layer OIHCLs can deteriorate the interfacial adhesion, and all mechanical performances of resultant composites.

Enhanced interfacial and mechanical properties of glass fabric/epoxy composites via grafting silanized carbon nanotubes onto the fibers

AbstractFor enhancing the interfacial adhesion of glass fabric (GF)/epoxy composites, silanized multi‐walled carbon nanotubes (MWCNTs) were used to treat GF surface, where carboxyl MWCNTs were functionalized by silane coupling agents based on the covalent or non‐covalent bonding, followed by the vacuum infusion process of laminated composites. A detailed study was employed to confirm the effects of silanized MWCNTs uniform dispersion and interfacial properties of resultant composites. Making full use of suitable silane coupling agents (γ‐aminopropyltriethoxysilane) treatment, the uniform MWCNTs dispersion and strong fiber/matrix interfacial adhesion could be achieved. Compared with the control sample, flexural and interlaminar shear strengths of resultant composites were enhanced by about 24% and 22%, respectively, indicating superior mechanical strength for composites; flexural modulus and storage modulus in the glassy state were improved by about 36% and 68%, respectively, suggesting higher stiffness for composites; the work of fracture (Wf) under interlaminar shear tests was raised by about 188%, revealing better interlaminar fracture toughness of composites. In addition, glass transition temperature of resultant composites also increased. This work provides a guiding strategy for manufacturing fiber‐reinforced composites requiring adjustable strength, stiffness, and toughness.Highlights Silane coupling agent was grafted on MWCNTs by covalent/non‐covalent bonding. Active groups of silanized MWCNTs induced crosslinking reactions with matrix. Silanized MWCNTs dispersion and glass fiber/matrix adhesion were improved. Strengthening/toughening mechanisms of laminated composites were analyzed.

Assessing thermophysical properties of parameterized woven composite models using image-based simulations

Mesoscale simulations of woven composites using parameterized analytical geometries offer a way to connect constituent material properties and their geometric arrangement to effective composite properties and performance. However, the reality of as-manufactured materials often differs from the ideal, both in terms of tow geometry and manufacturing heterogeneity. As such, resultant composite properties may differ from analytical predictions and exhibit significant local variations within a material.We employ mesoscale finite element method simulations to compare idealized analytical and as-manufactured woven composite materials and study the sensitivity of their effective properties to the mesoscale geometry. Three-dimensional geometries are reconstructed from X-ray computed tomography, image segmentation is performed using deep learning methods, and local fiber orientation is obtained using the structure tensor calculated from image scans. Suitable approximations to composite properties, using analytical unit cell calculations and effective media theory, are assessed. Our findings show that an analytical geometry and sub-unit cell geometry provide reasonable approximations of the full-scale predictions for the effective thermal properties of a multi-layer production composite.

Properties of fiber-gypsum composite formed on the basis of hemp (Cannabis sativa L.) fibers grown in Poland and natural gypsum

: Properties of fiber-gypsum composite formed on the basis of hemp (Cannabis sativa L.) fibers grown in Poland and natural gypsum. The popularity of composites reinforced with natural fibers is constantly growing and therefore, they are a subject of many scientific works as well. An example of interesting concept is the use of hemp fibers to reinforce a gypsum matrix and therefore, presented study was aimed to determine the effect of their content on the properties of resultant composites. Moreover, the influence of setting temperature was also investigated. The scope of the research included determination of properties such as: density, setting time, bending strength, modulus of elasticity and thermal conductivity coefficient. Studies have shown that as the amount introduced fibers increases, the density of manufactured composites decreases. Furthermore, increase in the content of hemp causes a significant extension in setting time of the gypsum matrix. Based on the outcomes of mechanical properties, it was found that the optimal content of fibers is 4% and further increase in their share results in a deterioration of flexural strength characteristics. The increase in a setting temperature leads to thereduction in their bending strength and modulus of elasticity. Composites reinforced with hemp fibers demonstrate significantly improved thermal insulation properties

Evaluating the effect of solid lubricant inclusion on the friction and wear properties of Laser Sintered Polyamide-12 components

The processing of Polyamide-12 (PA12) by Laser Sintering is one of the most well-established Additive Manufacturing (AM) processes for producing functional components for end-use applications. However, its further adoption within industry remains hindered by an incomplete understanding of resultant part quality and the impact this has on component wear. The scope of this research was to investigate the dry sliding behaviour of Laser Sintered Polyamide-12, as well as evaluate whether the inclusion of solid lubricant fillers effect the friction and wear properties of parts produced. Polytetrafluoroethylene (PTFE), Graphite and Molybdenum disulphide (MoS2) were added to Polyamide-12 powder in 1 : 100 mass ratios, respectively, to create three different polymeric composites. Mechanical blending and Laser Sintering then ensued; the latter was performed using identical processing parameters throughout. Tribological performance was evaluated by ball-on-flat uni-directional wear testing. Tensile testing was also carried out to help elucidate what wear mechanisms were active during sliding, as well as identify whether solid lubricant inclusion impacted mechanical performance. Results showed that in all instances solid lubricant inclusion significantly influenced the friction and wear properties of resultant composites, without compromising their mechanical performance when compared with neat-PA12. More specifically, it was demonstrated that the individual additions of PTFE and MoS2 could reduce the coefficient of friction and specific wear rate of Laser Sintered PA12 components by as much as 50% and 78%, respectively.

Sustainable jute fiber reinforced polylactic acid composite: Thermochemical and thermomechanical characteristics

The necessity of utilizing biodegradable and naturally sourced materials is rising all over the world. The preferred composite today are mostly sustainable but compatibility issues between the matrix and fiber still requires further investigation. The study presents development of Jute fiber (JF) reinforced Polylactic acid (PLA) composite with Fusabond (FB) as an interfacial modifier by using extrusion. The addition of interfacial modifier enhanced the thermomechanical and thermochemical properties of resultant composite. The improvement in elastic modulus and tensile strength is evident when 30%JF with 3%FB was utilized. The DMA result shows that the addition of Fusabond as interfacial modifier in jute fiber reinforced polylactic acid composite improves the storage modulus and enhances the toughness by reducing tanδ peak. Furthermore, SEM micrograph demonstrates the improvement in interfacial suitability between jute fiber and polylactic acid matrix when Fusabond is added. The X-ray tomography result shows when jute fiber content is 30% in PLA matrix higher degree of anisotropy is achieved which is 29%.

Effect of the addition of aliphatic diamine-functionalized carbon nanotubes on the interfacial adhesion of glass fiber/epoxy composites

To improve the interfacial adhesion of glass fiber (GF)/epoxy composites, the GF surface was treated by dispersing aliphatic diamine-functionalized multi-walled carbon nanotubes (MWCNTs). Carboxyl MWCNTs were first modified by aliphatic diamine with different alkyl chain lengths and then deposited on the surface of GF. The effect of aliphatic diamine chain lengths on the MWCNTs’ dispersion and interfacial properties of resultant composites was investigated in detail. The results showed that uniform dispersion of MWCNTs and strong fiber/matrix interfacial adhesion could be achieved, based on the grafting of 1,8-octanediamine onto MWCNTs. Compared with the control sample, the interlaminar shear, flexural, and tensile strengths of the treated composites increased by 41%, 29%, and 30%, respectively; the interlaminar fracture toughness and storage modulus in the glass region were significantly enhanced; and the glass transition temperature increased by more than 8°C. This work demonstrates that the carbon nanotubes functionalized by appropriate chain lengths of amine modifier can improve the fiber/matrix interfacial interactions and thus enhance the strength, toughness, and stiffness of fiber-reinforced composites.

Enhanced interfacial adhesion in glass fiber fabric/epoxy composites employing fiber surface treatment with aminosilane-functionalized graphene oxide

An economical and effective method was developed to optimize the interface of glass fiber fabric (GFf)-reinforced epoxy composites (GFfE) by dispersing aminosilane-functionalized graphene oxide (GO) on the fiber surface. The effects of γ-aminopropyltrimethoxysilane (APS) or APS hydrolysis on the dispersion of GO and the interfacial properties of resultant composites were investigated in detail. The results indicated that the uniform dispersion of GO in composites and strong fiber/matrix adhesion could be achieved, based on grafting of APS hydrolysis onto GO. The interlaminar shear, flexural and tensile strengths of resultant composites were improved by 28%, 22% and 19%, respectively; the storage modulus and dynamic glass transition temperature (1 Hz) were significantly enhanced, compared with pure GFfE. In particular, the work of fracture received from interlaminar load–deflection curves increased by 97%, indicating the toughening effect of GO. This work demonstrates that it is possible to enhance the strength, stiffness and toughness of fiber-reinforced composites by incorporating GO into the interface between the fiber and the matrix.

In Situ TiC/FeCrNiCu High-Entropy Alloy Matrix Composites: Reaction Mechanism, Microstructure and Mechanical Properties

In situ TiC particles-reinforced FeCrNiCu high-entropy alloy matrix composites were prepared by vacuum induction melting method. The reaction mechanisms of the mixed powder (Ti, Cu and C) were analyzed, and the mechanical properties of resultant composites were determined. Cu4Ti were formed in the reaction of Cu and Ti when the temperature rose to 1160 K. With the temperature further increased to 1182 K, newly formed Cu4Ti reacted with C to give rise to TiC particles as reinforcement agents. The apparent activation energy for these two reactions was calculated to be 578.7 kJ/mol and 1443.2 kJ/mol, respectively. The hardness, tensile yield strength and ultimate tensile strength of the 15 vol% TiC/FeCrNiCu composite are 797.3 HV, 605.1 MPa and 769.2 MPa, respectively, representing an increase by 126.9%, 65.9% and 36.0% as compared to the FeCrNiCu high-entropy base alloy at room temperature. However, the elongation-to-failure is reduced from 21.5 to 6.1% with the formation of TiC particles. It was revealed that Orowan mechanism, dislocation strengthening and load-bearing effect are key factors responsible for a marked increase in the hardness and strength of the high-entropy alloy matrix composites.

A novel strategy to reinforce glass fiber fabric/epoxy composites via modifying fibers with self‐assembled multi‐walled carbon nanotubes‐montmorillonite

AbstractA novel strategy of multi‐walled carbon nanotubes‐montmorillonite (MWCNTs‐Mt)‐modified glass fiber fabrics (GFf) was used here to reinforce interlaminar regions of epoxy composites. One/two‐dimensional MWCNTs‐Mt hybrids with different mass ratios of MWCNTs and Mt were combined with the GFf, respectively, prior to a resin injection process. Making use of this strategy, uniformly dispersed MWCNTs and highly exfoliated Mt at the fiber/matrix interface could be achieved; meanwhile, mechanical and interfacial properties of resultant composites were greatly enhanced. Under a mass ratio of MWCNTs:Mt (0.2:1), the interlaminar shear, tensile, and flexural strengths of resultant composites were improved by 31.0%, 26.0%, and 21.9%, respectively; the storage modulus increased by 23.6%, compared with the composite without MWCNTs‐Mt. Also, the work of fracture obtained from interlaminar load‐displacement curves and peak loss moduli of resultant composites were significantly enhanced, indicating the synergistic toughening effect of MWCNTs and Mt.

Surface modified cellulose nanocrystals for tailoring interfacial miscibility and microphase separation of polymer nanocomposites

High performance nanocomposites with good interfacial miscibility and phase separated morphology have received a lot of attention. In this work, cellulose nanocrystals (CNCs) were first grafted with hydrophobic poly(methyl methacrylate) (PMMA) chains to produce modified CNCs (PMCNCs) with increased thermal stability. Such surface-tailored CNCs effectively influenced the phase morphology and improved the mechanical properties of poly(butyl acrylate-co-MMA) (PBA-co-PMMA) nanocomposites. Morphological analysis indicated the presence of microphase separation in PMCNCs/PBA-co-PMMA nanocomposites with PBA as the soft domain and PMMA as well as CNCs as the hard domain. The nanocomposites with 10 wt% PMCNCs/PBA-co-PMMA showed increases in Young’s modulus of more than 20-fold and in tensile strength of about 3-fold compared to those of the unmodified PBA-co-PMMA copolymer. Therefore, the PMCNCs played a crucial role in controlling the interfacial miscibility and tuning the phase morphology of the nanocomposites. It is also essential to understand the role played by microphase separation in achieving nano-scaled morphological control and in fine-tuning the resultant composite properties.

Controllable mechanical properties of epoxy composites by incorporating self-assembled carbon nanotube–montmorillonite

A self-assembled multi-walled carbon nanotube−montmorillonite (MWCNT−Mt) hybrid wherein varied MWCNTs contents were attached on the exfoliated Mt was constructed and further used to reinforce epoxy composites. By just tuning mass ratios of MWCNT:Mt, the dispersion level of MWCNTs, exfoliation degree of Mt and ultimately mechanical properties of resultant composites could be controlled. The effect of MWCNT−Mt hybrids on structure-property relationships of epoxy composites was investigated. Under an optimal mass ratio of MWCNT:Mt (0.1:1), the toughness of epoxy composites was significantly enhanced, revealing the synergistic toughening effect of MWCNTs and Mt; the tensile and flexural strength of epoxy composites were improved by 26.8% and 20.4%, respectively; the storage modulus in the glassy region increased by 15.8%, compared with epoxy composite containing pristine Mt.

Thermal Conductivity and Tensile Properties of Carbon Nanofiber-Reinforced Aluminum-Matrix Composites Fabricated via Powder Metallurgy: Effects of Ball Milling and Extrusion Conditions on Microstructures and Resultant Composite Properties

Carbon nanofiber (CNF)-reinforced aluminum-matrix composites were fabricated via ball milling and spark plasma sintering (SPS), SPS followed by hot extrusion and powder extrusion. Two mixing conditions of CNF and aluminum powder were adopted: milling at 90 rpm and milling at 200 rpm. After milling at 90 rpm, the mixed powder was sintered using SPS at 560 °C. The composite was then extruded at 500 °C at an extrusion ratio of 9. Composites were also fabricated via powder extrusion of powder milled at 200 rpm and 550 °C with an extrusion ratio of 9 (R9) or 16 (R16). The thermal conductivity and tensile properties of the resultant composites were evaluated. Anisotropic thermal conductivity was observed even in the sintered products. The anisotropy could be controlled via hot extrusion. The thermal conductivity of composites fabricated via powder extrusion was higher than those fabricated using other methods. However, in the case of specimens with a CNF volume fraction of 4.0%, the thermal conductivity of the composite fabricated via SPS and hot extrusion was the highest. The highest thermal conductivity of 4.0% CNF-reinforced composite is attributable to networking and percolation of CNFs. The effect of the fabrication route on the tensile strength and ductility was also investigated. Tensile strengths of the R9 composites were the highest. By contrast, the R16 composites prepared under long heating duration exhibited high ductility at CNF volume fractions of 2.0% and 5.0%. The microstructures of composites and fracture surfaces were observed in detail, and fracture process was elucidated. The results revealed that controlling the heating and plastic deformation during extrusion will yield strong and ductile composites.

Aminated aligned carbon nanotube bundles/polybenzimidazole hybrid film interleaved thermosetting composites with interface strengthening action

Abstract It is always a big challenge to effectively enhance the impact resistance without sacrificing the processability and thermal stability of thermosetting composites. High performance diallyl bisphenol A modified bimaleimide (BD) thermosetting composites are fabricated by interleaving aminated aligned carbon nanotubes bundle (ACNTB-NH2)/polybenzimidazole (PBI) hybrid films. Because the hybrid film contains −NH2 and −NH− and ACNTB-NH2 protrudes from the film surface, the chemical interfacial interaction can be formed at hybrid film/matrix resulting from the reaction of −NH2 and −NH− in hybrid film and C=C in BD system, and the interface is strengthened by ACNTB-NH2 that can join the polymers together at the bimaterial interface like a rivet. The resultant BD/[5%ACNTB-NH2@PBI]n composites show greatly improved thermal stability and mechanical properties without sacrificing good dielectric property of BD, which can be attributed to the high inherent integrated properties of PBI hybrid films and the interface strengthening action between PBI hybrid film and BD matrix. The carbon fiber reinforced BD composites with PBI hybrid film interleaves are also fabricated, the mechanical properties of resultant composites show increasing trends with the increase of PBI hybrid film layer. Eventually, the flexural strength, impact strength and interlaminar shear strength of CF/BD/[5%ACNTB-NH2@PBI]5 increase by 16%, 42% and 33%, respectively, compared to those of CF/BD composite.

Thermo-Mechanical Performance of Polylactide Composites Reinforced with Alkali-Treated Bamboo Fibers.

In this study, polylactide acid (PLA) is filled with bamboo fibers (BFs) to fabricate a biodegradable natural composite for industrial applications. The influence of pre-treatment of BFs using 4 wt % sodium hydroxide (NaOH) solution at room temperature for 1 h on thermal and mechanical properties of resultant composites is systematically investigated. Differential scanning calorimetry and thermogravimetric analysis demonstrate that the incorporation of treated BFs promotes higher glass transition and crystallization temperatures of the resultant composites relative to untreated fiber composites, whereas alkali treatment results in superior thermal stability. Furthermore, the fracture surfaces are characterized by scanning electron microscopy. The changes in morphology reveal the possible dissolution of hemicellulose and lignin by alkalization with NaOH, indicative of an improved interfacial adhesion. An increment in the tensile strength of composites is achieved through the reinforcement with treated fibers. However, a lower tensile modulus is found for composites reinforced with chemically modified BFs, which might be due to the partial conversion of cellulose I into II. The results highlight that the use of BFs could be a feasible candidate as reinforcements for the development of biodegradable composites.

Tunable mechanical properties of MWCNT–glass fiber fabric reinforced epoxy composites by controlling MWCNTs dispersing conditions

A novel, simple and cost-effective method, which is capable of easily tailoring the dispersion of multi-walled carbon nanotubes (MWCNTs), was developed here to fabricate the MWCNT–glass fiber fabric (MWCNT–GFf) multiscale composites with tunable mechanical properties. MWCNTs were dispersed into the commercial GFfs through the combined effect of the ultrasound and amino silane (AS) firstly, followed by a resin infusion process. By tuning the ultrasonic power and AS concentration, it is possible to control the MWCNTs dispersion level and subsequently mechanical properties of resultant composite. Making use of optimal dispersion conditions, which involves the optimal combination of ultrasonic power and AS concentration, the interlaminar shear strength of MWCNT–GFf reinforced composites was dramatically increased by 40.5%, and the storage modulus in the glassy region and rubbery region was improved by 27.7% and 125.0%, respectively. The work demonstrates the great promise of this novel method toward practical, industrial application in manufacturing fiber-reinforced composites with superior mechanical properties.