RETRACTED ARTICLE: Physical, mechanical, and thermal behavior analyses of basalt fiber-reinforced composites

In this study, a novel thermotropic liquid crystal perylene bisimides polyurethane (LCPU) was synthesized using 3,4,9,10-perylenetetracarboxylic acid anhydride (PTCDA), hexamethylene diisocyanate (HDI), diglycolamine (DGA) and polyethylene glycol-200 (PEG-200) as raw materials. Based on the unique domain structure of π–π conjugate in perylenetetracarboxylic derivatives (PBIs), we modified the reduced graphene oxide (RGO) with LCPU. The graphene-based liquid crystal perylene bisimides polyurethane (LCPU/RGO) was prepared via π–π stacking interactions of RGO with LCPU. LCPU and LCPU/RGO were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), polarizing microscope (POM), wide-angle X-ray diffraction (XRD) and thermogravimetric analysis (TGA). LCPU/RGO was used to modify epoxy resins. The mechanical and thermal properties of the composites were systematically investigated. The results showed that the thermal and mechanical properties of the composites were enhanced effectively by the addition of LCPU/RGO. When the LCPU content was 0.7 wt%, the impact strength and bending modulus of composite were increased by 68.8 and 48.5 %, respectively, compared with neat epoxy. Its thermal decomposition temperature was 31 °C higher than that of neat epoxy.

Effect of preheat and encapsulation of steel particles on the interaction with Bisphenol A composites

We aimed to study the impact of surface modification of basalt fiber (BF) on the mechanical properties of basalt fiber-based epoxy composites. Four different types of pretreatment approaches to BF were used; then a silane coupling agent (KH550) was applied to further modify the pretreated BF, prior to the preparation of epoxy resin (EP)/BF composites. The combination of acetone (pre-treatment) and KH550 (formal surface treatment) for basalt fiber (BT-AT) imparted the EP/BF composite with the best performance in both tensile and impact strengths. Subsequently, such modified BF was introduced into the flame-retardant epoxy composites (EP/AP750) to prepare basalt fiber reinforced flame-retardant epoxy composite (EP/AP750/BF-AT). The fire behaviors of the composites were evaluated by vertical burning test (UL-94), limiting oxygen index (LOI) test and cone calorimetry. In comparison to the flame-retardant properties of EP/AP750, the incorporation of BF-AT slightly reduced LOI value from 26.3% to 25.1%, maintained the good performance in vertical burning test, but increased the peak of the heat release rate. Besides, the thermal properties and mechanical properties of the composites were investigated by thermogravimetric analysis (TGA), universal tensile test, impact test and dynamic mechanical analysis (DMA).

Oil palm empty fruit bunch (EFB) is one of the potential natural fibre that can be used as an alternative to synthetic fibre. EFB was heat-treated at 180°C using vacuum oven for 1 h, extrusion compounded with high-density polyethylene at 10%, 20% and 30% weight fraction. The composites were injection moulded into dumb-bell (ASTM D-638) and bar-shaped specimens (ASTM E-23). The composites were exposed to different environments which are soil burial and indoor environment for 3 months. The effects of conditioning on mechanical and thermal properties were studied relative to the dry as moulded samples as a standard. It was found that the mechanical and thermal properties of composites under soil burial conditions were reduced. Tensile modulus of 30% untreated fibre loading reduced from 1.56 GPa for dry to 1.03 GPa for soil burial conditions, respectively. The same reduction was also found in the flexural modulus. However, the value of treated fibre composites was found slightly higher compared to untreated fibre composites. The treated fibre composites showed more resistance towards the environment condition. Composites made from heat-treated EFB show improved thermal stability, expected due to better compatibility between fibres and matrices, thus lowering the moisture intake, despite the conditions of the samples. However, indoor exposure has no significant effect on the thermal and mechanical properties of composites.

This study describes the mechanical properties of Basalt fiber and Glass fiber reinforced hybrid composites developed by using compression moulding techniques. Woven Basalt fibers and Glass fibers were used for fabricating the hybrid composites, polyester resin as matrix with different fiber stacking sequences. The mechanical properties of hybrid composites like Flexural strength, Impact strength and tensile strength of the various specimens are calculated by using computer assisted Universal testing machine and Charpy Impact testing machine as per the ASTM standards. The result shows that the reinforcement of woven Basalt and Glass fibers hybrid composites significantly influencing on the mechanical properties of the composites and it found that the intermediate properties between basalt glass fibers reinforced composites.

The utilization of bamboo charcoal enhances wood plastic composites with excellent mechanical and thermal properties

In this study, the effect of thermal cycling on the mechanical and thermal properties of carbon/basalt fiber-reinforced polymer (CBFRP) composites is investigated. Carbon and basalt fibers are woven in Twill 2/2 pattern in the structure of intraply hybrid composite and fabricated by vacuum-assisted resin infusion molding method. Fabricated composite samples were exposed to 20, 40, 60, and 80 cycles between − 40 and + 120 °C. To evaluate the effect of thermal cycling on the mechanical and thermal properties of composites, tensile, bending, short beam shear and dynamic mechanic analysis tests were carried out. The extracted results such as tensile modulus and strength, flexural modulus and strength, interlaminar shear strength, storage modulus, loss factors and glass transition temperature of RT and samples that were exposed to different number of thermal cycles were compared with each other. It is concluded that increasing the cycle numbers in the beginning of thermal cycling leads to improvement of the mechanical properties of composites. This phenomenon occurs due to the post-curing in the structure of epoxy and enhancement of cross-links at the interface of the fibers and matrix. Increasing the cycle numbers leads to mismatch in the interface of the composite due to different coefficients of thermal expansion between the composite components and emergence of cracks and delamination in the structure of the composite that causes reduction in the mechanical and viscoelastic properties of the CBFRP composites. According to scanning electron microscopy, the fiber pullout, bundle breakage, fiber buckling, debonding and delamination were the most important failure modes in the mechanical tests.

Polymers are widely used as replacements for machined metal components in engineering applications. To withstand extreme contact conditions, reinforcing materials are often introduced into polymers to improve their mechanical and wear properties. This paper investigates the applicability of basalt fibres as reinforcing materials to enhance the mechanical and wear properties of polyetheretherketone (PEEK). The weight percentage of short basalt fibres in PEEK composites was 0-10% based on the injection moulding method. The mechanical properties and tribological behaviours of the resulting composites were investigated. The results showed that the composites filled with basalt fibres exhibit significant improvements in strength, anti-indentation creep and hardness. Meanwhile, the friction coefficient and wear rate of the composites decreased obviously due to basalt fibres on the top of the worn surface bearing the dynamic load under sliding. The morphology of the worn surface indicates that fibre pull-out and fibre breakage both contribute to energy dissipation. However, the mechanical properties of the composites did not increase linearly with increasing fibre content because of the decreasing bonding force between the fibres and the matrix. These results are significant for the application of PEEK in engineering.

Films from blends of polyurethane and nano-polytetrafluoroethylene aqueous dispersions (PU/nanoPTFE) were prepared, and the effect of the addition of different amounts of PTFE nanoparticles (50 nm) was studied. The changes in the superficial properties of the films were studied by means of XPS, ATR/FTIR, and contact angle measurements. SEM and TEM results are also included. The contact angle values confirm the surface hydrophobicity of composite films. Even though nanoparticles are present in the bulk, higher concentrations of particles appear at the surface in samples with lower nanoPTFE content (up to 10 wt%), as revealed by XPS. Higher amounts of nanoPTFE particles cause aggregation. The mechanical and thermal properties of composites are also discussed.

Epoxy composites with simultaneously enhanced tribological and mechanical properties filled with basalt belt/reduced graphene oxide/paraffin wax (EP/BF/RGO/PW) have been successfully prepared. Experimental results indicated that the mechanical property of the composites was reinforced by basalt belt, and the tribological property was greatly improved by reduced graphene oxide/paraffin wax at the same time. Thanks to the synergy of PW and RGO sheets, the optimized coefficient of friction and wear rate of the composite declined by 77.5% and 14.4% than pure EP under dry friction conditions of 60 N and 0.42 m s−1. In comparison to pure EP, the tensile strength and modulus of the optimized composite increased by 75.5% and 100% on account of the robust basalt fibers. Thus, the combination of basalt fiber and reduced graphene oxide/paraffin wax can readily realize the introduction of enhancer and oil‐impregnation in EP, offering a promising approach for simultaneously improving the mechanical and tribological properties of epoxy.Highlights A novel BF/RGO/PW 3D skeleton was developed via a facile hydrothermal method. The BF/RGO/PW can enhance the mechanical and tribological properties of EP. The basalt fibers account for the improvement in mechanical property. A reduction of 77.5% in COF and a decrease of 14.4% in wear rate were realized.

In the present experimental investigation, the utilization of euphorbia coagulum as a binder to fabricate euphorbia coagulum modified polyester bamboo fiber composite using a compression molding technique was studied. Composites were fabricated by varying the concentration of pristine bamboo fiber (BF) as well as alkali-treated bamboo fiber from 25% to 50% and also fabricated by the modification of polyester resin (PR) with euphorbia coagulum (EC). Structural and morphological changes of the fiber before and after alkali treatment were analyzed by XRD, SEM, FTIR, and the fabricated composites were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and mechanical properties by universal testing machine (UTM). Alkali treatment removed most of the hemicellulose and lignin content of the fiber which increases the surface roughness of the fiber and the nature of the fiber has been changed from hydrophilic to hydrophobic. It leads to facilitate the interlocking between fiber and matrix resulting in the improvement in mechanical properties of the composites. The maximum improvement in mechanical and thermal properties of composites were observed in case of 40% addition of both the pristine and alkali treated bamboo fiber in the polyester resin matrix. Moreover, it has been observed that with the addition of 30% euphorbia coagulum in the polyester resin further enhanced the mechanical and thermal properties of the composite and decreases the water absorption. The composites developed were found to be eco-friendly and cost effective, can be considered for the multipurpose panel, beam, pedestrian bridge.

In this study, composites based on polypropylene (PP), basalt fiber (BF), polypropylene-graft-maleic anhydride (MAPP) and different elastomers were manufactured by extrusion compounding and injection molding. The main focus of this study was to comparatively investigate the effect of three kinds of elastomers (ethylene–propylene–diene monomer (EPDM), polyethylene–octene (POE) and ethylene–vinyl–acetate (EVA)) on non-isothermal crystallization and mechanical properties of the composites with various BF contents. The tensile test results showed that BF had a reinforcing effect on PP resin, and the addition of MAPP further improved the tensile properties by the enhancement of PP/BF interfacial bonding. Among the elastomers, EPDM was more effective in improving the tensile strength and tensile modulus, while POE significantly toughened the impact strength. Micrographs of scanning electron microscope on the impact fracture surfaces indicated a good dispersion by the addition of POE and EPDM, while some agglomerations were observed in the presence of EVA. The non-isothermal crystallization kinetics were investigated based on Avrami and Mo equations at six different cooling rates by using differential scanning calorimetry. Micrographic images of polarized optical microscopy showed that the spherulite size of PP reduced in the presence of EPDM and EVA.

Composites based on pure Basalt and Basalt/Jute fabrics were fabricated. The mechanical properties of the composites such as flexural modulus, tensile modulus and impact strength were measured depending upon weave, fiber contents and resin. Dynamic mechanical analysis of all composites were done. From the results it is found that pure basalt fiber combination maintains higher values in all mechanical tests. Thermo-gravimetric (TG/DTG) composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to pure jute fabrics. Addition of basalt fiber improved the thermal stability of the composite considerably. Scanning electron microscopic images of tensile fractured composite samples illustrated that better fiber-matrix interfacial interaction occurred in hybrid composites. The thermal conductivity of composites are also investigated and thermal model is used to check their correlation.

The effects of carbon fiber amount and length were studied on the flame retardant, thermal, and mechanical properties of the intumescent polypropylene composites. The flame retardant properties of the intumescent polypropylene-based composites were investigated using limiting oxygen index, vertical burning test (UL-94), and mass loss calorimeter. The mechanical properties of the composites were studied using tensile test and dynamic mechanical analysis. According to the flammability tests results, the antagonistic interaction was observed between carbon fiber and ammonium polyphosphate. The limiting oxygen index value reduced steadily as the added amount of carbon fiber increased. Mechanical test results revealed that the addition of carbon fiber increased the tensile strength and the elastic modulus as the added amount increased. No effect of carbon fiber length was observed on the flammability, fire performance, and tensile properties of composites, whereas the elastic modulus increased as the carbon fiber initial length increased.

Epoxy polymers are commonly utilized in structural applications due to their high bearing capacity and excellent chemical resistance. However, their inherent brittleness poses a significant challenge for their use in high shock and fracture strength products. To address this shortcoming, fillers can be incorporated into the polymer during preparation. In this study, we aimed to investigate the effect of incorporating cellulose‐based fillers, namely cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC), on the mechanical properties of epoxy polymer composites. The study evaluated the impact of various factors, including filler concentration, particle size, and moisture content, on the mechanical properties of the composites. The results demonstrated that the incorporation of CNC or MCC powders at concentrations below 5% could enhance the mechanical properties of the resulting epoxy composites without adversely affecting their surface and thermal properties. The maximum tensile strength and fracture toughness of the filler‐based epoxy composites were achieved at 2 and 4 wt% for CNCs and MCC, respectively. CNCs with a smaller particle size distribution were found to be much more effective than MCC in improving the mechanical properties of the epoxy composites. Furthermore, utilizing dried fillers resulted in a higher improvement in tensile strength, which was achieved at lower filler concentrations.