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Thermoset and biothermoset applications have been advancing tremendously in recent years due to their easy processing, versatility, and exceptional mechanical and thermal properties. Biothermoset is a type of thermoset that is produced using biological resources, either in portions by blending with the conventional resin, or completely. Various research has been employed to accommodate their high and rapidly growing demands and broaden their functions and implementation in numerous fields. One of these attempts is the reinforcement of nanofillers. Nanofillers such as nanoclay, graphene nanoplatelets, carbon nanotubes, nanodiamond, etc., possess diverse and outstanding properties and are also easily accessible. Recently, there has been a developing trend of hybridizing two or more types of nanofillers as a hybrid reinforcement system to address the limitations of single-filler reinforcement systems and to establish better-supporting properties of the nanocomposites. In this review, we discussed the use of hybrid nanofillers in different thermoset and biothermoset applications. Emphasis is given to the types of hybrids, their interactions with each other and the host polymer, and the effects of their contents and ratios. Limitations from the previous works are also discussed and the future undertaking of research on hybrid nanofillers is also proposed.

Leather industries cause soil pollution in terms of leather wastes. Chrome-containing leather wastes (CCLW) also cause various types of pollutions such as air and soil pollution. The utilization of CCLW in the development of aluminum-based composite is the emerging area in the synthesis of materials. In this study, chromium(Cr) in the form of collagen powder was extracted from CCLW. Extracted collagen powder was ball milled with alumina particles for 12.5, 25, 50, 75, and 100 h. The average density of the mixture of ball-milled collagen and alumina particles was reduced by about 1.20% after ball milling for about 100 h. The stir casting technique was employed to develop the aluminum-based composite material. The ball-milled reinforced aluminum-based composite material showed a fair distribution of reinforcement particles as compared without ball-milled reinforced composite material. Tensile strength and hardness of composite material improved by about 35.53 and 46.61%, respectively, after using the mixture of ball-milled 5% collagen powder and 5% alumina particles in the aluminum alloy. However, ductility and toughness were reduced. Corrosion weight loss and thermal expansion of the Al/5% collagen/5% alumina particles with ball-milled composite were found to be 0.022 mg and 5.44 mm3, respectively. X-Ray diffraction of the Al/5% collagen/5% alumina particles with ball-milled composite showed the presence of Al, Al2O3, Cr2O3, and Cr phases. The presence of hard phases such as Al2O3, Cr2O3, and Cr was responsible for enhancing the hardness and tensile strength of the composite. The developed composite material can be utilized in the fabrication of engine blocks, connecting rods, and piston rings.

Processing of bionanocomposite film with various types and concentrations of plasticizers.

In this study, sugar palm crystalline nanocellulose (SPCNC)-reinforced thermoplastic sugar palm starch (TPS) was blended with poly(lactic acid) (PLA) in order to prioritize the biodegradation feature while offsetting individual polymer limitation. Prior to melt blending process, SPCNC was dispersed through sonication in advance of starch gelatinization which was later casted into petri dishes. PLA and TPS were melt blended into five different ratios using Brabender mixer followed by compression molding. Soil degradation (4 months) and water uptake (4 weeks) tests were conducted to evaluate the physical stability of PLA/TPS blend bionanocomposites. Based on Fickian law, the diffusion curve and coefficient of diffusion for seawater, river water, and sewer water were calculated. The flammability and limiting oxygen index (LOI) tests were conducted in accordance with ASTM D635 and ASTM D2863, respectively. For PLA60TPS40 (40% TPS), significant reduction (46–69%) was recorded in maximum water uptake in all mediums, while soil degradation rate experienced insignificant increment (7.92%) for PLA70TPS30 (30% TPS) owing to the reinforcement of SPCNC through the well-dispersed TPS within PLA. Meanwhile, the flammability rates and LOI values for PLA40TPS60 and PLA60TPS40 indicated flammable material properties.

The need for environmentally friendly composite materials that meet the necessary criteria is growing. Making novel environmentally acceptable composites with hybrid Eichhornia crassipes (EGs)/Al2O3 particles is an option. This paper aims to investigate the thermal, tensile strength, and flexural strength properties of a polyester composite filled with hybrid EG/Al2O3 particles. The tensile strength, flexural strength, and morphology of EGs/Al2O3 hybrid composite will be investigated in this work. The hot pressed for 60 minutes at 170°C procedure was used to shape the hybrid composite. EGs/Al2O3 particles content was altered from 0:25 to 5:20, 10:15 to 15:10, 20:5, and 25:0 (vol.%). The results reveal that when the EGs content of the composite is in the range of 10–15% (vol.%), the tensile and bending strength of the composite increases. The EGI (15% EGs:10% Al2O3) and EGH (10% EGs:10% Al2O3) composites had the highest tensile and bending strengths, with 38.697 and 77.786 MPa, respectively. The boost in strength is thought to be due to Al2O3 acting as a cursor in the composite, preventing fracture progression. The scanning electron microscope (SEM) fracture morphology reveals a strong and tight interfacial connection between the EGs, Al2O3, and polyester layers. In addition, when the EGs grew, the composites' thermal characteristics improved. According to the findings, the EGs/ Al2O3 particle hybrid composite can be used in automotive applications. [ABSTRACT FROM AUTHOR]

Dimethylformamide (DMF), a polar solvent, is commonly used for preparing graphene/epoxy nanocomposites. While previous research has commonly predominantly highlighted the improvement in physio-mechanical properties of these nanocomposites, the effect of DMF on processing and its direct influence on the final characteristics of MXene/epoxy nanocomposites have not been investigated. This unexplored link between DMF dosage, MXene concentrations, and the final composite properties presents an exciting direction for future research. In this study, a fixed dosage of DMF was used with varying MXene concentrations to fabricate the nanocomposites. To assess the reliability of DMF dosage on the characteristics of the fabricated nanocomposites, various evaluation techniques were employed, including dispersion evaluation, mechanical tests, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), electromagnetic interference (EMI) shielding, and surface roughness measurements. The research outcomes revealed that as MXene concentration increased, the characteristics of the MXene/epoxy nanocomposites, improved across the board, indicating their potential for use in energy storage applications. [ABSTRACT FROM AUTHOR]

Hybridization of natural fibers with ceramic materials for reinforcing composites allows the optimization of the properties of these materials. For this reason, the present study aims to investigate physical, mechanical, water absorption, swelling and thermal properties as well as morphological characteristics of a hybrid Paederia foetida fibers–alumina powder (PFs–Al2O3)‐reinforced epoxy composite. Epoxy resin served as the matrix, while PFs and Al2O3 were employed as reinforcement. Five types of composites were fabricated using the hot‐pressing technique. The corresponding ratios of PFs:Al2O3 volume fractions (%) considered here were 0:40 (SFA), 10:30 (SFB), 20:20 (SFC), 30:10 (SFD) and 40:0 (SFE). The results reveal that the density of the hybrid PFs–Al2O3 composites decreased for increasing volume fractions of PFs: from 2.173 g cm−3 of SFA to 1.042 g cm−3 of SFE. The highest values of tensile strength (i.e. 49.085 MPa), tensile elastic modulus (i.e. 1.431 GPa) and impact strength (24 kJ m−2) were obtained for the SFD composite material with 30% volume fraction of PFs and 10% volume fraction of Al2O3: this happened because interface bonds between PFs, Al2O3 and epoxy phases achieved their optimal configuration. Overall, mechanical properties of the hybrid PFs–Al2O3‐reinforced epoxy composites were superior to those of composites reinforced only by PF fibers or only by Al2O3. Water absorption and swellability reached their maximum values at the steady state occurring after tested samples remained immersed in water for 820 h. The SFE composite reinforced only by PFs presented the highest water absorption and swelling (i.e. 6.034% and 5.81%, respectively) while for all other hybrid composites (SFD, SFC and SFB) these two quantities remained below 5%. Density and volume fraction of voids of hybrid PFs–Al2O3‐reinforced composites were consistent with the corresponding properties of the composites reinforced only by Al2O3 or PFs. SFD was also the most thermally stable material. Scanning electron microscopy observations of fractured surfaces indicated that the microstructure of the PFs–Al2O3‐reinforced epoxy composites presents several voids, fiber pullouts and transverse fibers, which together optimize the mechanical response of the composite material. Remarkably, the SFD composite material was highly competitive with the most recently developed hybrid composites employing natural reinforcements. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

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