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This research paper focuses on the use of solid biomass waste, specifically a combination of Polyalthia longifolia seed (PLSF) and graphite (GH) powder, as reinforcements in vinyl ester (VE) composites. The composites were produced via the hand layup method, with the filler concentration varying from 0 to 15 wt% of PLSF and 0–9 wt% of graphite. The objective was to examine the influence of the hybrid filler on the mechanical characteristics of the composites. The mechanical properties of composites prepared from P. longifolia seeds and graphite powder were experimentally characterized. These properties included tensile strength, flexural strength, impact resistance, and hardness. The hybrid composite had a maximum tensile strength of 48.4 MPa, and its tensile modulus was 1.66 GPa. The hybrid filler at 15% wt% of PLSF and 6% of graphite has the highest flexural strength, which is around 148 MPa. The ultimate impact strength and hardness were measured to be 41.3 kJ/m2 and 44.5, respectively, after the addition of 15 and 6 wt% of hybrid filler. In comparison to neat vinyl ester resin, the PLSF/GH‐VE composites exhibited an increase in tensile, flexural, impact, and hardness of 2.69, 1.82, 3.03, and 1.59 times, respectively. Hybrid composite surfaces were analyzed using scanning electron microscopes to determine surface characteristics and fractured surfaces. In addition, the PLSF/GH‐VE composites have been utilized in the production of components for four‐wheelers. Highlights: Investigated the impact of hybrid filler‐reinforced vinyl ester composites.Mechanical and thermal properties were experimentally characterized.Surface characteristics and fractured surfaces were examined.PLSF/GH‐VE composites are used in producing components for four‐wheelers. [ABSTRACT FROM AUTHOR]

Graphene nanoplatelets (GNP) are just one of the attractive graphene-based nanomaterials that are rapidly emerging and have sparked the interest of many industries. These small stacks of platelet-shaped graphene sheets have a unique size and morphology that quickly disperse into other materials such as polymers, resulting in higher-value composite materials with improved thermal, conductivity, and mechanical capabilities. A detailed analysis of reinforced High-Density Polyethylene (HDPE) using different sizes (2, 15, 25 μm) and compositions (8, 10, 15 wt.%) of Graphene Nanoplatelets (GNP) has been conducted. The microstructure of the HDPE/GNP nanocomposites was extensively examined during the melt blending and injection moulding processes. Based on the results, the nanocomposites with different sizes of GNP exhibited dissimilar behaviour with different compositions. Furthermore, scanning electron microscope (SEM) results indicated a homogeneous dispersion for GNP in melt mixing. Moreover, thermogravimetric (TG) data demonstrate that increasing filler showed a slight increase in the material's thermal stability. The use of GNP improved mechanical properties, as evidenced by the increases in Young's modulus of yield strength from around 100 MPa to over 400 MPa. This study provides a practical reference for the industrial preparation of polymer-based graphene nanocomposites. [ABSTRACT FROM AUTHOR]

In this work, this study aimed to overcome the inherent disadvantage of low thermal stability and brittleness of epoxy resins. A novel modifiers containing alkynyl‐ and allyla‐ groups, (E)‐1‐(4‐(allyloxy)‐3‐methoxyphenyl)‐N‐(3‐ethynylphenyl)methanimine (MNEM) was prepared and confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H‐nuclear magnetic resonance (1H NMR), and selected to improve the thermal stability and toughness of bisphenol A‐type epoxy resin (E51). The blend resins were produced by blending with different contents of MNEM into E51 resin, named E‐MNEM resins. Meanwhile, the thermal stability, mechanical properties, and micromorphology of E‐MNEM blends were analyzed in details. It was found that the thermal stability of E‐MNEM resins was improved by increasing the proportion of MNEM. Compared with E‐0MNEM resin, when the MNEM concentration reached 40 wt%, the char yield (Yc) increased from 14.95 to 29.62%, reflecting a 98.1% improvement. In addition, an appropriate concentration of MNEM could be conductive to improving the mechanical properties. An improvement of 25.5 and 7.1% in elongation and tensile strength along with the maximum value of 17.6 kJ/m2 for the impact strength was achieved by the cured E‐MNEM resins containing 20 wt% of MNEM. Finally, the fracture surface morphology of the E‐MNEM resins was analyzed by the scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

Cyanate ester (CE) resins possess excellent thermal and mechanical characteristics, yet their brittleness and high cross‐link density limit their practical application. To overcome this limitation, the modification of CE with thermoplastic resins has been employed as an effective strategy to enhance their toughness and mechanical properties. In this study, a novel fluorinated poly(aryl ether nitrile) (PFPEN) with excellent solubility and thermal properties was synthesized through a nucleophilic substitution reaction. The effect of the addition of PFPEN on a blend composed of bisphenol A cyanate ester (ACE) and a mixed catalyst was investigated. Differential scanning calorimetry results showed that the addition of PFPEN facilitated the curing reaction of ACE, resulting in a lower exothermic peak temperature. Compared to the pure ACE, the addition of PFPEN at 20 phr significantly improved the tensile and impact strengths of the resin, as well as enhanced the lap shear strength at room temperature by 36% and the peel strength by 320%, respectively. The scanning electron microscope results showed a ductile fracture mechanism. However, it should be noted that the decrease in crosslinking density resulting from the addition of PFPEN may affect the lap shear strength at 300°C and the glass transition temperature (Tg) of the material. [ABSTRACT FROM AUTHOR]

Reactive polyimide (PI) containing phenolic hydroxyl groups was prepared by the polymerization of 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane and mixed thiodiphthalic anhydride. A series of epoxy resin composites were obtained by adding reactive PI to N,N,N′,N′ -tetraglycidyl-4,4′-diamino-diphenylmethane (TGDDM) epoxy resin in different proportions. The effect of PI content on curing behavior, thermal properties, and mechanical properties was carefully investigated. Even a small amount of PI addition improved the mechanical properties and heat resistance of the epoxy resin, particularly the fracture toughness. Among them, epoxy resin composites EP-PI-1.5 with the addition of 1.5 wt% PI showed the best mechanical properties, whose impact strength, fracture toughness, and tensile strength were increased by 114%, 59%, and 34%, respectively. The phase morphology was also investigated to illustrate the fracture mechanism by scanning electron microscope (SEM) characterization. [ABSTRACT FROM AUTHOR]

The article presents the results of research on polymer composites based on polypropylene filled with various fillers. The physical and thermal properties of the composites are the result of the used polymer matrix as well as the properties and geometric features of the used filler. The geometric shape of the filler is particularly important in the processing of plastics in which the flow is forced, and high shearing tension occurs, which determines the high macromolecular orientation and specific arrangement of the filler particles. Thermal analysis (STA) was used in the research and photographs were taken using a scanning electron microscope (SEM) of fractures of polymer composites. The following fillers were used: talc, fibreglass, glass beads, and a halogen-free nitrogen-phosphorus flame retardant. The test material was obtained by extrusion. Shapes for strength tests, which were subjected to scanning microscopy tests after a static tensile test, were obtained by injection. The carried-out tests allowed us to determine the influence of the type and shape of individual fillers on structural changes in the structure of polypropylene composites and the degree of sample weight loss in a specific temperature range, depending on the used filler. [ABSTRACT FROM AUTHOR]

In this study, a novel biobased allyl compound with Schiff‐based structure (MPAM) was developed to improve the toughness and thermal properties of 4,4′‐bismaleimidodiphenylmethane (BDM). The chemical structure of MPAM was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR). A series of BDM/DBA‐MPAM blend resins (BD‐MPAM resins) were prepared by adjusting the mass ratio of BDM + DBA (BD) to MPAM. The effects of MPAM content on the curing behavior, thermal and mechanical properties of BD‐MPAM resins were discussed in details. Compared with BD resin, the thermal stability of modified resins was improved by increasing the content of MPAM. Meanwhile, an increase of 37.1% in flexural strength, and 228 MPa in flexural modulus were obtained for the cured BD‐MPAM resin having 10 wt% MPAM loading compared to the BD resin. The impact strength of BD‐10 wt% MPAM is of the maximum value (6.6 kJ/m2). Finally, the fracture surface morphology of the BD‐MPAM resins was studied by the scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

The study deals with the mechanical and thermal characterization of novel composite consisting of vetiver grass fiber (Chrysopogon zizanioides) (VF) and red mud (RM) as reinforcement in epoxy resin. Five types of composites were fabricated using hand lay-up technique by varying the weight percentage (wt%) of vetiver grass and red mud. Various mechanical properties like tensile strength, impact strength, and flexural strength of the said composites were evaluated and discussed. The thermal properties in terms of thermo gravimetric analysis (TGA) were evaluated whereas the chemical composition characteristics were analyzed using FTIR and XRD spectroscopy. The fractured surfaces of the tested specimens were studied using a scanning electron microscope. From the results, it was observed that properties of polymer composites were improved by hybridization with vetiver grass fibers and red mud. The improved mechanical properties of fiber-reinforced composites were noticed in increment of wt% of red mud. Highest tensile strength of 51.78 MPa, flexural strength of 35.92 MPa and impact strength of 29 KJ/m2 was obtained for C5 composite which contains highest wt% of red mud. TGA shows better resistance to thermal degradation for the composites containing higher percentage of red mud. Looking at the results it can be concluded that the developed composites in this work can be an efficient alternative for building and automotive application which requires high strength and thermal stability. [ABSTRACT FROM AUTHOR]

The need for eco‐friendly materials has been attracted due to renewability, abundance availability, low cost, and so on. Therefore, the search for bio fillers for the fabrication of bio‐based composite materials is gaining more and more attention in both academic and industry circles because it promotes sustainability. The present study represents the utilization of biomass solid waste in the hybrid form of Tamarind Seed and Date Seed Filler (TSF/DSF) into polymer reinforced composite which has been explored for the first time by a compression molding technique. These fillers are bio‐waste that can be obtained at a minimal cost from renewable sources. An attempt has been made to use these hybrid fillers to reinforce the matrix ranging from 0 to 50 wt%, and their physical, mechanical, and thermal properties were investigated. In general, the inclusion of hybrid fillers increases mechanical properties, although the addition of hybrid fillers had only a minor impact on thermal properties. When compared to the pure vinyl ester resin, the hybrid fillers reinforced composites revealed a significant enhancement in tensile, flexural, impact, and hardness properties, with improvements of 1.51 times, 1.44 times, 1.87 times, and 1.46 times respectively, at 10 wt% filler loading. Filler matrix interaction of fractured mechanical testing samples was evaluated by scanning electron microscope. Based on the findings, hybrid filler reinforced composites may be suitable for applications where cost is a consideration and where minor compromises in thermal qualities are acceptable. [ABSTRACT FROM AUTHOR]

Carbon-based composite conductive ink (3CI) has some challenges to its properties. Here, combined with the application of 3CI on silicon keypads, a series of studies on the electrical, mechanical and thermal performance of 3CI has been conducted by adding specific concentrations of silver powder, silica powder and SiO2@Ag core-shell particles. The properties of the modified 3CI were characterized by using the four-point probe tester, scanning electron microscope, Rockwell hardness tester, cross-cut tester and laser thermal conductivity analyzer. The experimental results revealed that by adding silver powder with a particle size of 20 microns equivalent to 12% by weight of the 3CI, ink resistance decreased by 76%, from 8.44 kΩ/□ to 2.03 kΩ/□. Meanwhile, adding silica can increase the ink's tensile strength and thermal diffusivity while improving the adhesion of the 3CI on the silicone rubber. It was worth noting that when the particle size of the SiO2@Ag core-shell particle was smaller than that of the added silver powder, the resistance of the 3CI was further reduced. Finally, a modified 3CI with the adhesion of 4B, a conductivity of about1 kΩ/□, a hardness of 232 HV0.5, and a thermal diffusivity of 0.217 cm2s−1 was achieved experimentally, which provided an experimental basis for the modified 3CI suitable for silicone keypads. [ABSTRACT FROM AUTHOR]

Cyanate ester (CE) was employed to modify epoxy resin (EP) by chemical reaction, and the thermal, mechanical, and corrosion properties were systematically studied. Differential scanning calorimetry and Fourier transform infrared spectra were carried out to determine the curing kinetic parameters, suitable curing procedure, and reaction mechanism. The glass transition temperature and thermal stability were investigated employing dynamic mechanical thermal analysis and thermogravimetry measurement. Furthermore, the mechanical and corrosive properties were evaluated, using test techniques such as mechanical testing machine, abrasion tester, axle rod flexibility tester, scanning electron microscope, and electrochemical impedance spectroscopy. Results verified that an appropriate amount of CE could significantly improve the comprehensive performance of EP. However, a satisfactory effect would not be achieved when the modifier is inadequate or excessive. [ABSTRACT FROM AUTHOR]

This article addresses the effect of nanocrystalline cellulose (NCC) on the mechanical and thermal properties of polypropylene (PP). A new approach was adopted to produce mechanically improved and thermally stable PP-NCC nanocomposite. This approach involved producing optimized PP-NCC nanocomposite by adding NCC nanoparticles to PP matrix at different concentrations by means of injection molding process. The aim of this work was to find the optimum NCC concentration to enhance the mechanical and thermal properties of the PP matrix. The mechanical and thermal behavior of PP-NCC nanocomposite was studied by performing three-point bend, nanoindentation, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) spectroscopy tests. The results showed that the mechanical properties of strength, modulus, and hardness of the nanocomposites increased with the addition of NCC by 6.5%, 19%, and 150%, respectively. DSC results showed that the addition of NCC to PP does not affect the thermal stability (melting temperature). However, TGA showed that upon inclusion of NCC nanoparticles, the thermal stability of the samples improved compared to pure PP except for the 5% added NCC. This is attributed to the presence of NCC rod-like particles that dissipated heat by generating tortuous paths, as depicted in the SEM results and verified by FTIR results. [ABSTRACT FROM AUTHOR]

Nanoparticles have been widely used in the improvement of the mechanical and thermal properties of the epoxy matrix. In this study, the room temperature curing agent composed of acrylic acid and 2,4,6‐trimethyl‐m‐phenylenediamine was mixed with different concentrations of CeO2 nanoparticles into the epoxy resin (E51) to obtain a nanocomposite that can be rapidly molded and cured. Fourier transform infrared spectroscopy and differential scanning calorimetry were used to study the curing behavior of nanocomposites and E51 with the synthesized hardener. Through tensile, flexural, and impact tests, the influence of the nanoparticles content on the mechanical and thermal properties of the prepared composites was discussed. The results showed that the curing process was completed in 4 h. An increase of 78.4% in tensile strength, 81.7% in flexural strength, and 122.0% in elongation were obtained for the cured nanocomposite having 5 wt% CeO2 loading compared to the neat resin. Thermogravimetric analysis result showed that the thermal stability increased with increasing of CeO2 nanofillers content. Finally, the scanning electron microscope revealed the fracture surface morphology of the composites. [ABSTRACT FROM AUTHOR]

Thermal, electrical, as well as mechanical behavior of blends of polyamide 6/polystyrene (PA6/PS) (50/50 wt/wt%) loaded with different concentrations of lead dioxide (PbO2) were investigated for X-ray shielding. Thermal stability and hardness (shore D) of these composites are studied. Addition of PbO2 decreases the thermal stability of the prepared composites. Stability of thermal properties confirmed by determining the activation energy for the thermal decomposition of unfilled PA6/PS and filled composites according to the Horowitz and Metzger method. Dielectric properties of bulk PbO2 have been investigated as a function of frequency and temperature in the frequency range from 40 Hz to 5 × 106 Hz and in the temperature range from 293 K to 423 K. The characterization of the prepared composites is done using scanning electron microscope. With PbO2-loaded PA6/PS blends composites, the dielectric properties were significantly influenced by γ-irradiation effects that ε ′ and ε ″ values increase with radiation dose up to 100 kGy for samples loaded with PbO2. Linear attenuation coefficient μ and half-value layer (HVL) of all composites strongly depend on the concentration of the filler used and the applied voltage of X-ray machine. HVL of the obtained composites that loaded with 100 wt/wt% of PbO2 nearly 3 mm can be used as X-ray tube housing, equipment housings and castings, electronic devices protection, and so on. [ABSTRACT FROM AUTHOR]

In this study, composite was made by the addition of 10 wt% SiC particles in the LM25 matrix through gravity casting and thixocasting processes. Thixocasting temperature was varied to investigate its effect on the microstructure, mechanical and thermal properties. Properties of thixocast samples were also compared with gravity cast ones. XRD analysis was done to analyse the phases present in the samples. Optical microscope and scanning electron microscope were used to record the microstructures of gravity cast as well as thixocast samples. Tensile, compressive and flexural tests were performed on universal testing machine with the prepared composite samples according to the ASTM standards. Thermal diffusivity tests of gravity cast and thixocast samples were done on laser flash diffusivity instrument. Results reveal that thixocast samples are sounder than the gravity cast samples. The microstructure of α-Al phase transformed from dendritic to globular shape due to the thixocasting. Also, volume fraction of eutectic phase in the sample increased with the increment of thixocast temperature. Tensile strength, compressive strength and flexural strength were found higher in the case of thixocast samples as compared to gravity cast. Thermal diffusivity considerably increased due to thixocasting, while its value slightly reduced with increment of thixocast temperature. [ABSTRACT FROM AUTHOR]

High‐performance composites reinforced with natural fibers are next‐generation structural materials due to their recyclability and light weight. Manufacturing composites with high strength has been a challenge. Here, we describe the manufacture of novel composites reinforced with wood fibers using densification by hot‐pressing and fixing by curing reaction with phenolic resin. This composite with 1.4 g/cm3 had high mechanical properties, high water stability, and aging‐resistance, and exhibited a flexural strength and internal bonding strength of 102.4 and 7.5 MPa, respectively. The strength and modulus are 1.5–6.0 and 1.3–28.1 times higher than those of most of the wood fibers reinforced composites. After immersing in water for 24 h, the water absorption and thickness swelling are only 1.3% and 0.8%, respectively. Scanning electron microscope characterization indicates that the cell wall is totally collapsed and became complete densification. And the collapsed cells are fixed by phenolic resin. This production strategy for the composites was shown to be universally effective for various species of natural fibers. These novel wood fiber‐reinforced composites were suitable for commercial manufacture in the current production line, making them a low cost and high‐performance alternative to automotive and aerospace industries. [ABSTRACT FROM AUTHOR]

As an environmentally friendly material, alkali-activated fly ash-slag (AAFS) is considered as a promising alternative cement because of its excellent mechanical properties and thermal stability. Nevertheless, high temperature induced damage in AAFS can potentially bring serious risks for its practical applications. This paper presents a systematic experimental study on behaviour of AAFS paste subjected to elevated temperatures up to 800 °C in terms of microstructure as well as thermal and mechanical properties. Microstructural evolution was characterised by means of Rietveld-based quantitative X-ray diffraction (QXRD), backscattered scanning electron microscope (BSEM) and X-ray microcomputed tomography (XCT), while thermal and mechanical properties were evaluated from thermogravimetric analysis (TGA), thermal deformation and compressive and flexural strengths. Results indicate that the compressive strength of AAFS paste rises by 77.5 % at 200 °C, followed by a mitigation from 200 to 600 °C and a regain at 800 °C. Different phases in AAFS paste including unreacted particles, reaction products and pores took up 30 %, 67.7 % and 2.31 % at ambient temperature, and 4.95 %, 84.8 % and 10.3 % after exposure to 800 °C, respectively, suggesting the recrystallisation with the formation of nepheline and gehlenite. In addition, the relationships between microstructural characteristics including three-dimensional (3D) pore structure features and thermal and mechanical properties of AAFS paste at elevated temperatures were explored and discussed in depth to gain insights into the underlying degradation mechanisms including pore pressure build-up, thermal gradient and phase transformation. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) materials constituted by a microencapsulated paraffin having a melting temperature of 6°C and a thermoplastic polyurethane (TPU) matrix were prepared through fused deposition modeling. Scanning electron microscope (SEM) micrographs demonstrated that the microcapsules were homogeneously distributed within the matrix, with a rather good adhesion within the layers of 3D printed specimens, even at elevated concentrations of microcapsules. The presence of paraffin capsules having a rigid polymer shell lead to a stiffness increase, associated to a decrease in the stress and in the strain at break. Tensile and compressive low‐cycles fatigue tests showed that the presence of microcapsules negatively affected the fatigue resistance of the samples, and that the main part of the damage occurred in the first fatigue cycles. After the first 10 loading cycles at 50% of the stress at break, a decrease in the elastic modulus ranging from 60% for neat TPU to 80% for composite materials was detected. This decrease reached 40% of the original value at 90% of the stress at break after 10 cycles. Differential scanning calorimetry tests on specimens after fatigue loading highlighted a substantial retention of the original TES capability, in the range of 80%–90% of the pristine value, even after 1000 cycles, indicating that the integrity of the capsules was maintained and that the propagation of damage during fatigue tests took probably place within the surrounding polymer matrix. It could be therefore concluded that it is possible to apply the developed blends in applications where the materials are subjected to cyclic stresses, both in tensile and compressive mode. [ABSTRACT FROM AUTHOR]

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Hybrid matrices (epoxidized of ethylene–propylene–diene monomer (eEPDM) -g- aminopropyltriethoxysilane (APTES)/hydroxyl terminated polydimethylsiloxane (HTPDMS)/polyurethane (PU)) were developed based on eEPDM with 3-APTES coupling agent and varying weight percentages (0.75, 1.50, 2.25, and 3.00 wt%) of PU prepolymer as coreactant using 7.5 wt% of HTPDMS as chain extender using suitable experimental conditions. The formation of hybrid matrices and their structure were characterized by Fourier transform infrared (FTIR). The thermal and morphological properties of the hybrid matrices were analyzed using differential scanning calorimetry and scanning electron microscope, respectively. Mechanical properties (tensile strength, elongation at break (%), Young's modulus, and hardness) were characterized as per ASTM standards. Data resulted from mechanical studies, it was noticed that the incorporation of 3-APTES, HTPDMS, and PU into eEPDM has improved the elongation at break (%) and lowered the values of tensile strength, Young's modulus, and hardness according to the percentage concentration. Morphological studies indicate the presence of heterogeneous morphology. Data obtained from different studies, it suggested that the hybrid matrices developed in the present work can be used as cable insulates for high-performance industrial and engineering applications. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to investigate octavinyl‐polyhedral oligomeric silsesquioxane (OV‐POSS) incorporation into natural rubber (NR)/butadiene rubber (BR) elastomer blends as a potential compatibilizer. The effects of OV‐POSS loading levels on the thermal, mechanical, morphological, and dynamic‐mechanical properties of elastomer blends were explored. Fourier‐Transform Infrared Spectrometer (FTIR), Temperature Scanning Stress Relaxation (TSSR), and Differential Scanning Calorimetry (DSC) results revealed the conceivable effect of OV‐POSS nanoparticles in the vulcanization through reacting with sulfur and/or elastomers. Scanning Electron Microscope (SEM), X‐Ray Diffraction (XRD), and tensile test measurements supported the improvement of mechanical properties due to homogeneous dispersion at low loading levels. On the other hand, high amount of OV‐POSS incorporation (7 and 10 phr) resulted in a decrease in mechanical properties, owing to the agglomeration of nanoparticles. According to contact angle and Dynamic mechanical analysis (DMA) results, it could be concluded that OV‐POSS nanoparticles were localized at the interface of the elastomers and enabled the compatibilization of immiscible NR/BR blends. [ABSTRACT FROM AUTHOR]

Laboratory tests were conducted to study the physical and mechanical properties of granite after heating and water-cooling treatment for 1 and 30 cycles from room temperature to 500 °C. The change mechanisms for the water-cooling treatment were analysed via scanning electron microscope observation. At 500 °C, the volume of granite increases by 1.73% and 2.55%, the mass decreases by 0.16% and 0.31%, and the density decreases by 1.86% and 2.78% after 1 and 30 thermal cycles, respectively. The average values of UCS and E after 1 and 30 cycles both decrease as the temperature rises, while the peak strain exhibits the reverse trend. A yield platform is observed in the yield stage of the stress–strain curve above 300 °C, and the ductility of granite gradually increases with temperature. The normalized P-wave is linear with respect to the normalized UCS and E at 1 thermal cycle, whereas it shows exponential relationships with the normalized UCS and E at 30 thermal cycles. The degradation of the physical and mechanical properties of granite after 1 and 30 cycles is mainly caused by the generation and development of microcracks inside the rock. Compared to 1 thermal cycle, more microcracks are observed at 30 thermal cycles. Therefore, the thermal cyclic treatment can further deteriorate and weaken the physical and mechanical properties of granite. [ABSTRACT FROM AUTHOR]

The first aim of this study was to compare influences of various contents of the micro‐ (200 nm) and nano (50 nm)‐sized titania (TiO2) particles especially on the mechanical performance of the polylactide (PLA) biopolymer. Micro‐ and nano‐composites were prepared by twin‐screw extruder melt mixing, while the specimens were shaped by compression molding. Scanning electron microscope analyses and mechanical tests revealed that due to the most efficient uniform distribution in the matrix, the best improvements in the strength, elastic modulus, and fracture toughness values could be obtained either by using 5 wt% micro‐TiO2 or by only 2 wt% nano‐TiO2 particles. The second purpose of this study was to investigate influences of using maleic anhydride (MA)‐grafted copolymer (PLA‐g‐MA) compatibilization on the performance of one nanocomposite composition. Due to the improved chemical interfacial adhesion, use of PLA‐g‐MA compatibilization for the specimen of PLA/2 wt% n‐TiO2 composition resulted in the highest improvements in the mechanical performance of neat PLA. The improvements were 14% in tensile strength, 20% in flexural modulus, and as much as 67% in fracture toughness. Thermal behavior of all specimens was also observed by differential scanning calorimetry and thermogravimetric analyses. [ABSTRACT FROM AUTHOR]

Safer environmental requirements have resulted in significant interest in natural polymer-based materials to increase sustainability. In this perspective, wood polymer nanocomposites are of particular interest. Wood polymer nanocomposites were prepared from modified soybean oil, wood flour and cetyl trimethylammonium bromide modified bentonite using the compression-molding technique. Fourier transform infrared spectroscopy and X-ray diffractometric studies were used to confirm the successful modification of bentonite. Incorporation of 3 wt% of bentonite in the composites produced significant improvement in properties compared to those of 1 and 5 wt%. Furthermore, in comparison to the unfilled nanocomposites, nanoclay-filled ones showed an enhanced UV resistance property as judged by lower weight loss and carbonyl index. The decrease in mechanical properties of UV-exposed unfilled composites was more significant compared to those of nanoclay-filled composites. Scanning electron microscope and transmission electron microscope were used to study the surface morphology and distribution of the bentonite into the composites. In addition, with the incorporation of bentonite, significant increase in thermal, mechanical and flame-retarding properties was observed. [ABSTRACT FROM AUTHOR]

In this study, the influence of nanosilica (SiO2 NPs) on the mechanical, thermal and barrier properties of poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites was investigated. The PBAT/SiO2 composites were prepared by solution blending technique. PBAT/SiO2 composites were prepared with different percentages of nano-SiO2 loading (1, 3, 5, 7 and 10 wt%). The relations of SiO2 NPs with PBAT matrix were analyzed by Fourier transform infrared spectroscopy. The mechanical properties such as tensile strength, % of elongation at break, tensile modulus and thickness were determined. The thermal properties such as thermo-gravimetric analysis were analyzed for the nanocomposites. The PBAT/SiO2 composites exhibit high mechanical and thermal performance than the pure PBAT. The nanocomposites were also investigated through scanning electron microscope (SEM) and transmission electron microscope micrographs to examine the morphology between PBAT and SiO2 NPs. In addition, the results of SEM acquired are in SiO2 agreement with the data resulting from FTIR and tensile strength of the nanocomposites. The nanocomposite shows improvement in mechanical and thermal stability than that of pure PBAT. [ABSTRACT FROM AUTHOR]

The effect of high gamma irradiation and nanosilica on the structure and mechanical properties of the acrylonitrile butadiene rubber seal materials was investigated in this study. Acrylonitrile butadiene rubber nanocomposites containing (25, 50 and 75 phr) unmodified and modified nanosilica were irradiated at different doses (0, 0.2, 0.4, 0.6, 0.8, 1 MGy). The dispersion of nanosilica-based filler in acrylonitrile butadiene rubber was investigated by scanning electron microscope. Fourier-transform infrared analysis, swelling, crosslinking, mechanical and the thermal resistance properties of acrylonitrile butadiene rubber nanocomposites were investigated. From the results, it is clear that with modified nanosilica, acrylonitrile butadiene rubber phase crosslinking is accelerated with increasing γ-doses compared to unmodified nanosilica and seems to enhance physical, mechanical and the thermal properties of the rubber. The surface of the acrylonitrile butadiene rubber nanocomposites was investigated by scanning electron microscope and found better dispersion for acrylonitrile butadiene rubber with 25 phr of modified nanosilica at 0.6 MGy. The compression set of the results indicated that 25 phr modified nanosilica has best properties under high gamma irradiation. [ABSTRACT FROM AUTHOR]

Abstract Tungsten and boron compounds belong to the group of superhard materials since their hardness could exceed 40 GPa. In this study, the properties of the tungsten boride WB x coatings deposited by radio frequency magnetron sputtering were investigated. The sputtering was performed from specially prepared targets that were composed of boron and tungsten mixed in a molar ratio of 2.5 and sintered in Spark Plasma Sintering (SPS) process. WB films were deposited on silicon (100) and stainless steel 304 substrates at temperatures of 23 ÷ 770 °C. Microstructure, chemical and phase composition were investigated by using Scanning Electron Microscope (SEM), X-Ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD), respectively. The mechanical properties like Vickers hardness and Young's modulus were obtained by using nanoindentation test at a load of 5 ÷ 100 mN. The friction coefficient and wear resistance of αWB coatings were investigated in scratch test and reciprocal sliding wear instrumentation. Moreover, in order to investigate thermal properties, the αWB films were annealed at 1000 °C in argon/air for 1 h and at 250 °C for 2 h in air atmosphere. Results of our research confirm that αWB coatings can be considered as an alternative to superhard materials in the production of wear resistant, long-lasting tools. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the influence of cyclohexane/ethanol, alkali, and silane treatments on the waste hemp fibers and their polybenzoxazine composites. The Fourier transform infrared (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA) tests were carried out to understand the influence of treatments on the fibers. FTIR results revealed that hemicellulose and lignin of the fibers were removed after washing with cyclohexane/ethanol, and thermal stability of the fibers was improved after the alkali and silane treatments. The consequences of the treatments on the hemp fiber composites were studied by evaluating the mechanical, thermomechanical, thermal, and water uptake properties. The flexural, tensile and impact tests results confirmed that the silane treated fiber composites displayed highest properties than the other treated fiber composites. Furthermore, the stiffness and glass transition temperature of the silane treated fiber composites were also best among the studied composites. Moreover, the thermal stabilities values showed the lowest decline for the silane treated composites; due to the better thermal stability of the silane treated fibers, and lowest water absorption was also recorded for the silane treated fiber composites. The morphological studies confirmed that the silane treated fiber composite had stronger fiber/matrix adhesion interface. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present research findings on the measurements of mechanical, morphological, and thermal properties of Roselle fiber-reinforced thermoplastic polyurethane composites. The Roselle fiber/thermoplastic polyurethane composites were prepared with fibers of different sizes such as 125 µm and lower, 125–300 and 300–425 µm by internal mixer and hot press at 170°C. The results show that mechanical properties (tensile, flexural, and impact properties) of the composites were improved with the increase in fiber sizes. The highest tensile (10.45 MPa), flexural strength (6.93 MPa), and impact strength (20.22 kJ/m2) was obtained from composites with 300–425 µm fiber size of Roselle fiber/thermoplastic polyurethane composites. Morphological properties of dispersion fiber and tensile fracture surfaces were studied using scanning electron microscope. Thermal properties of the composites were studied using thermogravimetric analyses and results showed that the thermal decomposition effect was almost similar for all compositions. [ABSTRACT FROM PUBLISHER]

Ni/Al laminates are of great interest in many aerospace and military applications due to their excellent mechanical properties. However, their application has been limited in part due to challenges related to fabricating complex geometries. However, explosive welding is regarded as a promising technique to fabricate laminates. However, it is difficult to fabricate Ni/Al/Ni laminates with high interfacial shear strength and ductility if the stand-off distance has not been optimized during the explosion process. The goal of this study was to investigate the effect of stand-off distance on the microstructure and mechanical properties of Ni/Al/Ni laminates, and SEM and EDS were used to characterize the morphology and element distribution of the double layer interface. Tensile and tensile-shear tests were conducted to evaluate the mechanical properties of the laminates. The results indicated that with the increase in stand-off distance, three different kinds of interface were obtained (straight, wavy and continuously melted). Thickness of atomic diffusion layer increased with the increase in stand-off distance. Moreover, the Ni/Al/Ni laminates with wavy interface possessed highest value of ductility and interfacial bonding strength. [ABSTRACT FROM AUTHOR]

The potential of using of sub-microalumina/titanium particles as a reinforcement that can produce multifunctional polymer composites was explored. Novel multifunctional composites have been developed by incorporating sub-microalumina/ titanium particles into polyamide6. The composites were investigated for their thermal, viscoelastic, water uptake and mechanical properties, as a function of alumina/titanium concentration. A detailed study of the morphological observation by scanning electron microscope was used to correlate the microstructures to the mechanical properties. Flexural testing shows that the flexural modulus and strength of the composite are improved by 22%, and 15%, respectively, with incorporating 10 wt% alumina/titanium. In addition, the impact strength was improved by about 19%. Furthermore, 10 wt% alumina/titanium increases the interfacial shear strength of polyamide6 by about 23%. [ABSTRACT FROM AUTHOR]

With the flourish development of energy-saving solutions for building, the demands of phase change material (PCM) modified building materials are urgently increasing. Herein, we report a novel route to prepare clay geopolymer mortar incorporated PCM by vacuum absorption method, where PCM is produced with paraffin as heat-absorbing material and expanded perlite as p supportive material by vacuum adsorption method. The paraffin immobilized in three-dimensional network structure during the process of phase change is evidenced by scanning electron microscope (SEM), different scanning calorimetry (DSC), compressive strength, dry density and thermal conductivity. The proportion of paraffin in the composite is 55.47% by mass, and the phase change temperature and latent heat were 35.59 °C and 96.77 J/g, respectively. The compressive strength, dry apparent density, and thermal conductivity coefficient were 8.0 MPa, 1678 kg/m 3 , and 0.46 W m −1 K −1 , respectively. [ABSTRACT FROM AUTHOR]

Blends of cis-polyisoprene (CPI) and nitrile butadiene rubber (NBR) in different volume ratio were prepared to see the effect of composition on different properties. Structure characterization has been done through X-ray diffraction and scanning electron microscope. Scanning electron micrographs confirm homogeneous nature of all the blends. The dynamic mechanical analyzer was used to measure damping, storage modulus, glass transition temperature and mechanical properties (Young's modulus and tensile strength) of these blends. Activation energy and fragility were determined for the non-Arrhenius (fragile) behavior of viscosity using Vogel-Fulchuer-Tammann (VFT) equation. Thermal conductivity has been analyzed through thermal constant analyzer. Results indicate that all the measured properties are dependent on blend composition and crosslink density. [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, copper (Cu) crystallites were successfully prepared via low temperature molten salt method, and the possible formation mechanisms were proposed. The conductive fillers of multiwalled carbon nanotubes (MWCNTs) and as-prepared Cu particles were designed and introduced into acrylonitrile-butadiene-styrene (ABS) blend to prepare different conductive composites. The dispersion states of conductive fillers and the morphologies of the composites were characterized using a field emission scanning electron microscope. The electrical resistivity of different composites was measured. The results showed that Cu and MWCNTs exhibited a synergistic effect in decreasing the electrical resistivity of the Cu/MWCNTs/ABS composites, because Cu that could locate between MWCNTs chain segments provides a better charge transport in the conductive pathways. Compared with pure ABS, the tensile strength, elastic modulus and thermal stability of the Cu/MWCNTs/ABS composites were significantly improved with the incorporation of Cu and MWCNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41738. [ABSTRACT FROM AUTHOR]

The poly(styrene-b-butadiene-b-styrene) (SBS) triblock copolymer and linear low-density polyethylene (LLDPE) were blended and irradiated by γ rays to prepare shape memory polymer (SMP). Different weight fractions of conductive carbon black (CB) were filled into SMP to form a novel electroactive shape memory CB/SBS/LLDPE composite. The CB reinforced radiation cross-linked SBS/LLDPE blends for the improvement of the mechanical weakness and conductivity of SBS/LLDPE bulk and for wide practical engineering uses. The electroactive shape memory CB/SBS/LLDPE composites were investigated by electrical properties, mechanical, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and electroactive shape memory effects. It is found that the tensile strength, storage modulus, and resistance against mechanical and thermal mechanical cycle loading in the developed composites increased due to the role of reinforcement of CB. The melting temperatures and volume resistance of the composites decreased with the increment of CB for excellent electrical conductivity of CB. The electroactive shape memory effects of developed CB/SBS/LLDPE composites were affected by CB weight fractions and applied voltage, while good shape recovery could be obtained in the shape recovery test. When the CB fraction is more than 5 wt%, full recovery can be observed after tens of seconds and shape recovery speed increased with CB fractions and voltage increasing. However, the shape recovery rate decreases slightly with increment of cycle times. [ABSTRACT FROM AUTHOR]

The aim of this paper is to promote the use of mine clay washing residues for the preparation of alkali activated materials (AAMs). In particular, the influence of the calcination temperature of the clayey by-product on the geopolymerization process was investigated in terms of chemical stability and durability in water. The halloysitic clay, a mining by-product, has been used after calcination and mixed with an alkaline solution to form alkali activated binders. Attention was focused on the influence of the clay's calcination treatment (450–500–600 °C) on the geopolymers' microstructure of samples, remaining in the lower limit indicated by the literature for kaolinite or illite calcination. The mixtures of clay and alkali activators (NaOH 8M and Na-silicate) were cured at room temperature for 28 days. The influence of solid to liquid ratio in the mix formulation was also tested in terms of chemical stability measuring the pH and the ionic conductivity of the eluate after 24-h immersion time in water. The results reported values of ionic conductivity higher for samples made with untreated clay or with low temperature of calcination (≥756 mS/m) compared with values of samples made with calcined clay (292 mS/m). This result suggests that without a proper calcination of the as-received clay it was not possible to obtain 25 °C-consolidated AAMs with good chemical stability and dense microstructure. The measures of integrity test, pH, and ionic conductivity in water confirmed that the best sample is made with calcined clay at 600 °C, being similar (53% higher ionic conductivity of the eluate) or equal (integrity test and pH) to values recorded for the metakaolin-based geopolymer considered the reference material. These results were reflected in term of reticulation and morphology of samples through the analysis with scanning electron microscope (SEM) and X-ray diffraction (XRD), which show a dense and homogeneous microstructure predominantly amorphous with minor amounts of quartz, halloysite, and illite crystalline phases. Special attention was dedicated to this by-product to promote its use, given that kaolinite (and metakaolin), as primary mineral product, has a strong impact on the environment. The results obtained led us to consider this halloysite clay very interesting as an aluminosilicate precursor, and extensively deepening its properties and reactivity for the alkaline activation. In fact, the heart of this work is to study the possibility of reusing this by-product of an industrial process to obtain more sustainable high-performance binders. [ABSTRACT FROM AUTHOR]

Natural fibres used as reinforcing materials in polymer matrix composites provide positive environmental benefits with respect to ultimate disposability and best utilization of raw materials. Banana fibre is waste from banana trunks or stems which are abundant in many places in the world. To benefit the environment, agricultural industry as well as other industries, there is a need for development of new usage of agricultural waste. Natural fabric based green composites were prepared by hand lay-up technique with natural woven banana fabric (WBF) and Isophthalic acid based unsaturated polyester resin (UPR) as matrix. The mechanical, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and morphological properties of these green composites were investigated. The WBF were treated with 6% aqueous solution of NaOH. Untreated and NaOH treated fabric surfaces were analyzed by using Fourier transform infrared spectroscopy (FT-IR) and Scanning electron microscope (SEM) studies was carried out to evaluate fabric/matrix interactions. Thermogravimetric analysis of the samples indicated better thermal properties of the alkali treated fibres. The improved fabric--matrix interaction is evident from the enhanced tensile and flexural properties. Reduction in water absorption of alkali treated WBF/UPR composite was observed. The results proved that appropriate alkali treatment of banana fabric improved interfacial adhesion, and in turn mechanical and water absorption properties of the green composite made in this study. [ABSTRACT FROM AUTHOR]

Nanocomposites of poly(vinylidene fluoride) (PVDF) with chemically reduced graphene nanosheets (GNs) were prepared by melt mixing method and their structure and morphology characterized by SEM analysis. The addition of GNs in the PVDF matrix resulted in changes of the crystallization and melting behaviors. Furthermore, increasing GNs content led to improved thermal stability of the PVDF nanocomposites in air and nitrogen, as well as significant increase in tensile and flexural properties. The nanocomposites' rheological behavior is also affected by the GNs' content. Using oscillatory rheology to monitor the GNs' dispersion, it was found that as the GNs loading increase, the Newtonian behavior disappears at low frequency. This suggests a viscoelastic behavior transition from liquid-like to solid-like, with greater GNs content and more homogeneous dispersion resulting in a stronger solid-like and nonterminal behavior. By using the melt mixing method to disperse GNs, the properties of PVDF are enhanced due to the better dispersion and distribution of GNs throughout the matrix. This improvement could broaden the applications for PVDF nanocomposites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Cyanogen functionalized carbon nanotube and graphene/poly (arylene ether nitrile) (CNT-CN/GN-CN/PEN) nanocomposite films were prepared by a facile solution casting method. The weight ratio of CNT-CN/GN-CN was varied from CNT-dominated to GN-dominated for the purpose of investigating their synergetic effects on the mechanical and thermal properties of PEN nanocomposites. Consequently, GN-CN/PEN composites demonstrated better mechanical and thermal properties than CNT-CN/PEN composites due to larger contact area between GN-CN and PEN matrix. Nevertheless, all CNT-CN/GN-CN/PEN composites exhibit enhanced mechanical properties than those of GN-only nanocomposites. With the increasing of CNT-CN/GN-CN weight ratio, the mechanical properties of CNT-CN/GN-CN/PEN composites increase, then decrease, and reach their maximums when CNT-CN/GN-CN weight ratio is around 4/4. From scanning electron microscope images, it is found that around that point GN-CN is flatly dispersed and CNT-CN is penetrated into GN-CN, capable of transferring stress load and thus decreasing interface loss. Thermal properties of CNT-CN/GN-CN/PEN composites once again confirmed the joint effect of CNT-CN and GN-CN, leading to improved thermal properties. In short, a synergistic effect between one-dimensional (1-D) CNT and two-dimensional (2-D) GN on the mechanical and thermal properties of nanocomposites have been demonstrated in these systems. [ABSTRACT FROM AUTHOR]

Three kinds of poly(urea-formaldehyde) (PUF) microcapsules filled with epoxy resins (MCEs) were applied to bismaleimide (BMI)/ O,O′-diallyl bisphenol A (BA) system to develop novel fiber reinforced BMI/BA/MECs composites. The effects of MCEs on the mechanical properties, the hot-wet resistance, and the dynamic mechanical properties of fiber reinforced BMI/BA composites were investigated. The morphologies of fiber reinforced BMI/BA/MCEs composites were characterized by scanning electron microscope (SEM) and optical microscope (OM). Results indicate that the appropriate contents of MCEs can significantly improve the mechanical properties and the hot-wet resistance of fiber reinforced BMI/BA composites. In this study, MCEs may decrease the storage modulus of fiber reinforced BMI/BA composite but they have no significant influence on the glass transition temperature ( Tg) of the composite. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Wood flour (WF) was chemically modified with silanes such as 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and vinyltrimethoxysilane. Polypropylene (PP) composites reinforced with the chemically modified WF were prepared by melt compounding and injection molding. The effects of the silane treatments on the fundamental properties of wood fiber-reinforced PP composites were investigated by the measurement of mechanical properties, water absorption (WA), thermal properties, and scanning electron microscope (SEM) analysis. Silane treatments significantly improved tensile, flexural, and impact strengths of the composites, but it was found that there is no distinct difference among silanes. Silane treatments provided the decreased WA of the composites. From thermogravimetric analysis, the effect of the silane treatments on the thermal properties of the composites was not observed. From differential scanning calorimetric analysis, crystallization temperature and crystallization enthalpy were increased by the silane treatments, and crystallinity was decreased by the treatments. SEM photomicrographs show the evidence of the improved mechanical and WA properties of the PP/WF composites by the silane coupling treatments. [ABSTRACT FROM AUTHOR]

PVC/nano CaCO3 composites were prepared on Brabender Plasticorder. For comparison purposes, commercial CaCO3 composites were also prepared. Characterization of the nano CaCO3 and nanocomposites were done using scanning electron microscope (SEM) and transmission electron microscope (TEM). Their mechanical and thermal properties were also studied. Exfoliation was observed with the addition of different sizes of nano CaCO3 filled in PVC composites. Best properties were observed with 9 nm CaCO3 PVC composites. Tensile strength and modulus improved significantly even though the amount of addition of nano filler is low. Thermal properties of PVC/nanocomposites were found to be better compared to that of commercial filled CaCO3 in PVC composites. [ABSTRACT FROM AUTHOR]

Polyamide-CaCO3 nanocomposites were prepared by melt intercalation on twin-screw extruder. Various particle sizes (23, 17 and 11 nm) of CaCO3 were synthesized by in-situ deposition technique. The shape and sizes of nano-CaCO3 particles were confirmed by transmission electron microscopy (TEM). Nano-CaCO3 was added from 1 to 4 wt% in the polyamide. Properties such as Tensile strength, Elongation at break, Hardness, and Flame retardency were studied. These results were compared with commercial CaCO3 filled composites. Nano-CaCO3 filled in polyamide shows, 3 fold improvement in Young's modulus in comparison to commercial CaCO3 and 4-7 folds to virgin polyamide. Besides that, a polyamide nanocomposite shows 2 times improvements in flame retarding and vicat softening properties compared to commercial CaCO3. Moreover, thermal degradation was studied on TGA and found to be improved compared to commercial CaCO3. This was due to uniform dispersion of nano-CaCO3 with greater surface area in comparison to commercial CaCO3 in the polyamide matrix. Extent of dispersion of nano-CaCO3 was studied along with microcracks generated during tensile testing using scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

Polyamide/Ca3(PO4)2 nanocomposites were prepared via melt intercalation on twin-screw extruder. Different particle sizes (21, 17, 11 nm) of Ca3(PO4)2 were synthesized by in situ deposition technique and its sizes were confirmed on X-ray difractometer. Amount of loading of nano-Ca3(PO4)2 in the polyamide was ranges in the 1 to 4-wt%. Properties such as tensile strength, elongation at break, hardness, and flame retardency were studied. These results were then compared with commercial Ca3(PO4)2 filled polyamide composites. Improvement in properties was due to uniform dispersion of nano-Ca3(PO4)2 and commercial Ca3(PO4)2. Moreover, thermal property like degradation, weight loss was studied on TGA. Extent of dispersion of nano-Ca3(PO4)2 was studied along with cracks generated during tensile testing using scanning electron microscope (SEM). Nano-Ca3(PO4)2 was found to be thermally more stable compared to that of commercial Ca3(PO4)2. Besides that, the shape and sizes of nano-Ca3(PO4)2 was confirmed on transmission electron microscope (TEM). [ABSTRACT FROM AUTHOR]

This study aimed to investigate the influences of stamping temperature (or molding temperature) on thermal properties of matrix, mesoscopic structures of fabric and effective macroscopic mechanical properties of composite materials through experimental characterization. The plain woven carbon fiber/polypropylene composite laminates were prepared by hot stamping at 190 °C, 220 °C and 250 °C, respectively. Thermal study was performed using differential scanning calorimeter and thermogravimetric analysis. The mesoscopic properties were characterized through microscope and scanning electron microscope (SEM). Tensile test and short beam shear test were conducted to evaluate macroscopic properties of the material. Effects of fabric structure on the crack initiation and propagation as well as local strain concentration of thermoplastic composite were investigated in detail using digital image correlation (DIC) technique. Relationships of process parameters, thermal characteristics, mesoscopic fabric structures and macroscopic mechanical properties of the carbon fiber reinforced polypropylene (CF/PP) materials were explored under different stamping temperatures. The experimental results revealed that with increase in processing temperature, the crystallinity of polypropylene (PP) matrix increased, and the interfacial adhesion between fiber and resin became strong, leading to increase in tensile modulus. Due to the change of resin viscosity, the aspect ratio, crimp angle and gap size of the fiber bundles also vary. The interfacial debonding was a main failure mode in CF/PP composites. This study is anticipated to provide fundamental understanding in how to tailor effective properties of composites through manufacturing process. [ABSTRACT FROM AUTHOR]

• UHPC incorporated with MPCM was developed as structural–functional integrated construction material. • MPCM-UHPC possesses high mechanical properties and favorable heat storage efficiency. • Good chemical compatibility between UHPC and MPCM was experimentally verified. • The addition of MPCM strengthened the interface between steel fiber and matrix. A novel structural–functional integrated concrete (MPCM-UHPC) with excellent mechanical properties and thermal storage capacity was developed by incorporating microencapsulated phase change material (MPCM) into ultra-high performance concrete (UHPC). The indoor tests were performed to determine the thermal performance of MPCM-UHPC. Mechanical properties and autogenous shrinkage strain of MPCM-UHPC were evaluated. The microstructure, thermal stability, chemical structure and crystal structure of the composite material were investigated by mercury intrusion porosimetry (MIP), scanning electron microscope (SEM), thermal gravimetric analyzer (TGA), Fourier transformation infrared spectroscope (FTIR) and X-ray diffraction (XRD). The results show that no chemically phenomenological interaction between MPCM and cementitious components occurs in the hydration process. However, the incorporation of MPCM increased air voids content in cementitious matrix, thus inducing harmful effect on the mechanical properties and autogenous shrinkage of MPCM-UHPC. From indoor performance test, the surface temperature of UHPC with 10 wt% MPCM was 3.9 °C lower than that of control group. Compressive tests results show that it possesses a considerable compressive strength of 78 MPa. Therefore, the MPCM-UHPC composite is a promising structural–functional integrated building material. [ABSTRACT FROM AUTHOR]

The effects of heat treatment at different temperatures in the supercooled liquid region on the thermal properties, mechanical properties and corrosion behaviors of deformed Zr 65 Cu 15 Ni 12.5 Al 7.5 bulk metallic glasses (BMGs) are studied. Scanning electron microscope (SEM), differential scanning calorimetry (DSC), potentiodynamic polarization and electrochemical impedance are performed to characterize surface morphology, thermal properties, and corrosion resistance. Furthermore, the uniaxial compression test is conducted to investigative the mechanical properties of the alloy. The thermal stability of BMGs is apparently reduced as the heat-treated temperature increases. The as-cast possesses a maximum plastic deformation of about 19.5%. However, with the increase of heat-treated temperature, the plastic strain of the samples decreases, which is about 14.5% (at 643 K for 10 min), 9.5% (at 663 K for 10 min), and 3.0% (at 683 K for 10 min), respectively. Additionally, the corrosion resistance of the deformed alloys after heat treatment is superior to that of the deformed alloys before heat treatment, but it is still not as good as that of the as-cast. • Heat treatment in the supercooled liquid region on deformed Zr 65 Cu 15 Ni 12.5 Al 7.5 BMGs. • Thermal, mechanical and corrosion properties varied with heat treatment temperatures. • The shear bands can be repaired to a certain extent. [ABSTRACT FROM AUTHOR]

• Using Response Surface Methodology to understand properties of polyvinyl alcohol/acrylonitrile on bamboo nanocomposite. • Characterization and optimisation mechanical properties of polyvinyl alcohol/acrylonitrile on bamboo nanocomposite. • Modification using chemical improved the properties of polyvinyl alcohol/acrylonitrile on bamboo nanocomposite. Bamboo is a natural resource that has prospect to substitute wood in many engineering applications. In this work, mechanical properties of bamboo nanocomposite based on polyvinyl alcohol (PVA)/acrylonitrile/nanoclay was evaluated using response surface methodology (RSM). The developed nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infra-red (FTIR), Scanning electron microscope (SEM), Differential scanning colometry (DSC), and Thermo gravimetry analysis (TGA) to study their compositional, morphological and thermal properties. Models were developed to predict modulus of elasticity and modulus of rupture of the nanocomposites. The developed models fitted the experimental values with R2 close to 1 and residuals normal probability plot fitted to straight line. Optimized values of MOE and MOR were 12.82 GPa and 105.52 MPa respectively at 10 wt% clay loading, 15 wt% PVA/acrylonitrile loading and modification time of 5 min. The melting and decomposition temperature of the nanocomposites have shown significant improvement compared to the raw bamboo. [ABSTRACT FROM AUTHOR]

Poly(lactic) acid (PLA) is one of the most promising biobased materials, but its inherent flammability limits its applications. A novel flame retardant hexa-(DOPO-hydroxymethylphenoxy-dihydroxybiphenyl)-cyclotriphosphazene (HABP-DOPO) for PLA was prepared by bonding 9,10-dihydro-9-oxy-10-phosphaphenanthrene-10-oxide (DOPO) to cyclotriphosphazene. The morphologies, mechanical properties, thermal stability and burning behaviors of PLA/HABP-DOPO blends were investigated using a scanning electron microscope (SEM), a universal mechanical testing machine, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), limiting oxygen index (LOI), vertical burning (UL-94) and a cone calorimeter test (CCT). The LOI value reached 28.5% and UL-94 could pass V-0 for the PLA blend containing 25 wt% HABP-DOPO. A significant improvement in fire retardant performance was observed for PLA/HABP-DOPO blends. PLA/HABP-DOPO blends exhibited balanced mechanical properties. The flame retardant mechanism of PLA/HABP-DOPO blends was evaluated. [ABSTRACT FROM AUTHOR]