Tensile Strength Of Nanocomposites Research Articles

Mechanical, morphological, and numerical evaluation of biocompatible ultra‐high molecular weight polyethylene/nano‐zeolite nanocomposites

AbstractThe incorporation of bio‐friendly nano‐zeolite (NZ) into ultra‐high molecular weight polyethylene (UHMWPE), renowned for its exceptional biocompatibility, presents an intriguing pathway for robust structural biomedical applications. This study aimed to investigate the influence of NZ integration on the tensile and impact properties of UHMWPE/NZ nanocomposites through experimental and morphological assessments. The morphology examinations primarily entailed particle distribution, clustering extent, and the primary toughening response induced by fillers under impact loading. Fourier transform infrared spectroscopy (FTIR) was utilized to investigate the bonding characteristics between NZ and UHMWPE within the nanocomposites. Moreover, differential scanning calorimetry (DSC) was employed to examine alterations in the crystalline structure of the nanocomposites, revealing an increase of up to 9% in crystallinity () following the incorporation of NZ. Tensile tests demonstrated significant improvements, with a 45% increase in tensile modulus and a 14% increment in strength upon the inclusion of NZ. Impact toughness consistently showed enhancements of up to 24%. The improved impact strength was attributed to the extensive partial particle‐induced debonding and subsequent release of plastic constraints within the matrix. The micro‐mechanisms responsible for nanoparticle‐triggered toughening were further investigated using super‐magnified images from impact‐fractured SEM micrographs, and various impact toughening mechanisms were observed, classified, and discussed in the UHMWPE/NZ nanocomposites. Various analytical solutions were employed to predict the elastic modulus and tensile strength of nanocomposites. Subsequently, the results were compared to experimental data, and any discrepancies were thoroughly justified.Highlights The mechanical traits of UHMWPE/nano‐zeolite nanocomposites were explored. Tensile and impact strength increased up to 14% and 24% with NZ addition. Morphological inspections were conducted to assess filler‐induced debonding. Toughening mechanisms were assessed through super‐magnified SEM micrographs. Micromechanical models were used to predict the tensile modulus and strength.

Indole-functionalized polythiourethane/tetrapodal shaped ZnO nanocomposites for eco-friendly marine biofouling control

Antifouling coatings for marine use are a widely employed method for controlling the settlement and growth of unwanted aquatic organisms on surfaces. In this study, indole derivative N-(1H-5-bromo indole-3-ylmethyl) acrylamide (BIAM)-functionalized polythiourethane (PTU)/tetrapodal shaped zinc oxide (t-ZnO) nanocomposites (PTU/BIAM/t-ZnO) were synthesized through a Friedel–Crafts Alkylation reaction, thiol-ene click reaction and polyaddition reaction. Nanocomposites' surface characteristics, such as surface free energy, chemical composition, and surface morphology were investigated here. The mechanical characteristics and antifouling properties of the coating materials were also considered. These nanocomposites exhibited not only superior mechanical properties, due to the presence of both PTU and t-ZnO, but also promising antifouling properties owing to the incorporation of BIAM on their surfaces. The adhesion strength of the nanocomposites increased from 0.26 MPa to 0.68 MPa due to the incorporation of t-ZnO particles. Benefiting from the PTU matrix, the tensile strength of nanocomposite can reach over 57 MPa. The PTU/BIAM/t-ZnO nanocomposites demonstrated improved algae resistance and marine antifouling performance compared to the reference PTU/t-ZnO nanocomposite without indole derivative. The PTU/BIAM/t-ZnO nanocomposites exhibit resistance to fouling organisms due to the synergistic effect of the easy-to-clean characteristic of the PTU/t-ZnO and the reduction of the polar component of the surface free energy resulting from the inclusion of indole derivative BIAM on the surface. This, in turn, reduces the interaction between fouling organisms and the material surface. Furthermore, BIAM interferes with the homeostasis of cellular calcium ions, thereby hindering the attachment of fouling organisms. Under the combined action of PTU, BIAM, and t-ZnO, the synergistic effect of good antifouling properties, environmental compatibility, good mechanical properties and strong adhesion to the substrate was achieved.

Mechanical and Fracture Characterization of Epoxy/PLA/Graphene/SiO2 Composites

This work investigated the effects of graphene and SiO2 addition on the mechanical and fracture properties of epoxy (80%) - Polylactic acid (PLA) (20 %) composites. Epoxy-PLA composites were loaded with graphene and SiO2 (0.1-0.5 wt. % with equal weightage of each filler), and were manufactured by bath sonication followed by manual casting. The tensile, flexural strength and fracture toughness of nanocomposites increased with an increase in filler concentration till it reached 0.3 wt. %. The addition of filler content higher than 0.3 wt. % drastically reduced the mechanical and fracture properties. The fractured surfaces from the tensile tests were examined using Scanning electron microscopy imaging to understand the effects of filler addition. The numerical analysis was also performed to simulate the impact of filler concentration on the tensile strength of nanocomposites using representative volume element (RVE) in ANSYS workbench.

Study of Thermal Effect on the Mechanical Properties of Nylon 610 Nanocomposites with Graphite Flakes That Have Undergone Supercritical Water Treatment at Different Temperatures.

This study investigates the thermal effect of supercritical water treatment at different temperatures (150, 175, 200 °C) and semi-vacuum state (-0.08 MPa) on graphite flakes which are then incorporated into nylon 610. The treatment is deemed to increase the surface activity of nanofillers through the formation of oxygen-containing functional groups. X-ray diffraction (XRD) analysis indicated that the crystal structure of the flakes remained similar before and after supercritical water treatment. Fourier transform infrared spectroscopy (FTIR) also showed the presence of hydrogen bonding between the flakes and the polymer matrix through the appearance of amide bands. The intensity of the amide peaks is higher for nanocomposites with treated flakes than untreated ones. Furthermore, scanning electron microscopy (SEM) showed that at higher wt%, aggregation will occur, which leads to a weakening in physical properties. The tensile strength of nanocomposites with treated flakes decreased with increasing wt%, while those with untreated flakes increased with increasing wt%. Young's modulus of all the nanocomposites generally increased with increasing wt%. The highest tensile strength obtained is 967.02 kPa, while that of neat nylon 610 is 492.09 kPa. This enhancement in mechanical properties can be attributed to the intact structure of the graphite flakes and the interaction between the flakes and the nylon 610 matrix. A higher temperature of water treatment was discovered to cause higher oxidation levels on surface of the nanofillers but would result in some structural damage. The optimum nylon 610 nanocomposite synthesized was the one that was incorporated with 1.5 wt% graphite flakes treated at 150 °C and -0.08 MPa, as it has the highest tensile strength.

On the mechanical properties of melt-blended nylon 6/ethylene-octene copolymer/graphene nanoplatelet nanocomposites

Ethylene-octene copolymer (EOC) with a loading level of 20 wt%, maleated EOC (EOC-g-MA) with a loading level of 3 wt% and graphene nanoplatelets (GnPs) at four different loading levels, i.e., 3 wt%, 5 wt%, 10 wt% and 15 wt% were added to nylon 6 to prepare nanocomposites using a twin-screw extruder with a high shear rate screw running at 300 rpm. Increased stiffness was observed with the addition of GnPs while tensile strength of nanocomposites was only slightly influenced. Addition of GnPs into nylon 6 and nylon 6/EOC blend caused either a reduction in the Charpy impact strength or it remained unaffected. Similarly, the Izod impact strength of compatibilized nylon 6/EOC blend increased while that of nylon 6/EOC blend-based nanocomposites decreased. An increase was observed in the compressive Izod impact strength of compatibilized nylon 6/EOC blend. Addition of GnPs to nylon 6/EOC blend caused an increase in the fracture toughness due to their influence on the morphology and fracture mechanisms. This study shows that simultaneous addition of high surface area GnPs and an impact modifier to neat nylon 6 can help achieve enhancement and tailoring of stiffness and toughness.

UIO-66 as Nucleating Agent on the Crystallization Behavior and Properties of Poly(Ethylene Terephthalate).

In this study, not only was the similar terephthalate structure between UIO-66 and PET utilized to improve compatibility, but the Zr4+ exposed by defects of UIO-66 was also utilized to improve the interaction between PET and UIO-66. Furthermore, PET nanocomposites with different contents of UIO-66 were also fabricated. Due to the high specific surface area and coordination of Zr4+, UIO-66 has high nucleation efficiency in the PET matrix. Compared with pure PET, the crystallization rate of PET/UIO-66 nanocomposite is significantly increased, and the crystallization temperature of PET-UIO66-1 is significantly increased from 194.3 °C to 211.6 °C. In addition, the tensile strength of nanocomposites has also been improved due to coordination.

Investigation on the effect of GMA-graft structure in SAN-g-GMA-coSt on inter-phase behavior, thermal stability, and mechanical properties of PC/SAN/GO nanocomposites

In this study, the effect of simultaneous presence of graphene oxide (GO) nanoparticles and styrene-assisted glycidyl-methacrylate-grafted SAN copolymer (SAN-g-GMA-coSt), as a compatibilizer, on inter-phase behavior, microstructure, thermal, and mechanical properties of PC/SAN blends was investigated. First, the structure of GMA-grafts on the surface of the SAN copolymer was adjusted to improve the compatibility of the blend components. The role that processing conditions play in grafting efficiency was comprehensively studied by FTIR and H-NMR techniques. The results indicated that the optimized SAN-g-GMA-coSt contained grafted sequences consist of 5 GMA molecules dispersed in every 387 carbons of the straight SAN chains. This structure of GMA-grafts reduced phase separations of the blend components and the size of droplets. GO localization in the system, controlled by two-step mixing method, was studied theoretically and the prediction was confirmed by the experimental results. The DSC and DMTA thermograms illustrated that the inter-phase region expanded probably by interactions between functional groups on the surface of GO and the epoxy section of GMA. In addition, thermogravimetric and mechanical results indicated that incorporation of nanoparticles in the presence of SAN-g-GMA-coSt increased the residual mass (char yield) at 600 C and tensile strength of nanocomposites by 55% and 37%, respectively.

Poly(Butylene Terephthalate) Filled with Sb2O3 Nanoparticles: Effects of Particle Surface Treatment, Particle Size, Particle Morphology and Particle Loading on Mechanical Properties of Composites

Poor dispersion of nanoparticles in polymer matrix would limit the development and application of particulate-filled polymer composites. Therefore, the Sb2O3 nanoparticles were functionalized by a combination of cetyltrimethyl ammonium bromide (CTAB) and silane coupling agent KH-560 via water bath modification method so as to improve the dispersion of Sb2O3 nanoparticles in poly(butylene terephthalate) (PBT) matrix and enhance the interfacial adhesion between nanoparticles and polymer matrix. Besides, the coating efficiency of compound modifiers on the surface of Sb2O3 nanoparticles was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The Sb2O3 nanoparticles with different morphologies were systemically measured using transmission electron microscopy and dynamic light scattering measurement. The effects of particle surface treatment, particle size, particle morphology and particle loading on mechanical properties of composites were studied by the X-ray diffraction (XRD), tensile test machine and impact strength machine. The tensile strength of nanocomposites gradually increases with decreasing the particle size at the same amount of Sb2O3 nanoparticle fillers, which is attributed to improvement of interfacial contact area and stronger interfacial adhesion between Sb2O3 nanoparticles and PBT matrix. And the compound modified Sb2O3 nanoparticles are homogeneously dispersed in PBT matrix and play an important role in the properties enhancement. Moreover, taking consideration of the tensile and impact strengths, the optimal loading is 3 wt%.

Hybrid Rubber Nanocomposites Based on XNBR/EPDM: Select the Best Dispersion Type from Different Nanofillers in the Presence of a Compatibilizer

Hybrid rubber nanocomposite blends based on (80/20) XNBR/EPDM containing 5 phr Cloisite 10A, 15A 20A, 25A, 93A, 30B, carbon black and silica nanofiller and two types of EPDM-g-MA and ENR 50 containing 5 phr was prepared by a two roll mill. A rheometer test was used to study the curing of the blends, the tensile test was used to study the mechanical strength of the nanocomposite and XRD, FESEM and TEM tests were used to evaluate and observe the morphology of the nanocomposite blends prepared. The results of the rheometer test show that the Cloisite 30B nanofiller, in addition to increasing the torque and optimum cure time, decreased compared to other nanofillers. The results of the XRD test showed that the ENR50 compatibilizer with the Cloisite 30B nanofiller compared to other nanofillers, compared to the EPDM-g-MA compatibilizer, significantly increased the openness of the layers by 2.21 nm. The results of FESEM and TEM confirmed the better distribution of Cloisite 30B nanoparticles in the XNBR/EPDM sample containing ENR 50 compatibilizer. Also, XRD evidence showed that the opening of the nanofiller layers of Cloisite 30B was higher the other nanofillers. This result is consistent with microscopic observations. In addition, all nanoparticles are located in the XNBR phase. The results of the tensile test showed that the modulus and tensile strength of nanocomposite containing Cloisite 30B nanofiller and ENR 50 compatibilizer with other nanocomposites increased.

Analysis of critical interfacial shear strength between polymer matrix and carbon nanotubes and its impact on the tensile strength of nanocomposites

This paper focuses on the critical interfacial shear strength (τc) and interfacial shear strength (τ) between polymer matrix and carbon nanotubes (CNT) in nanocomposites, which divide the interphase region to two zones: τ < τc near the polymer matrix and τ > τc beside the CNT. “τc” is defined by CNT properties and a model is developed to consider the roles of “τ” and “τc” in the tensile strength of nanocomposites. Numerous experimental data for various samples and the parametric examines are applied to approve the developed approach. The high aspect ratio of CNT (thin and long CNT) produces a low “τc”, but the CNT strength directly influences the “τc”. The suitable agreement between experimental data and calculations for all samples and the proper roles of all parameters in the tensile strength of nanocomposites confirm the developed model. Low “τc” and high “τ” cause a high nanocomposite strength, but the strength of nanocomposites largely increases when τ > 5 τc.

Research on WPU‐RGO/ATP‐Fe3O4/chitosan composites with excellent electrical and magnetic properties

First, attapulgite‐Fe3O4 magnetic filler (ATP‐Fe3O4) was prepared by using a chemical precipitation method. Subsequently, graphite oxide (GO) was prepared through Hummer method, and then reduced GO (RGO) was prepared through GO reduced by chitosan (CS). Finally, a series of WPU‐RGO/ATP‐Fe3O4/CS composites were prepared by introduced RGO/ATP‐Fe3O4/CS to waterborne polyurethane. The structure and properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), vibrating sample magnetometry (VSM), thermogravimetric analysis TGA, conductivity test, and tensile test. The experimental results indicated that thermal stability and tensile strength of nanocomposites were improved with the increase of the content of RGO/ATP‐Fe3O4/CS. Meanwhile, with the increase of the RGO/ATP‐Fe3O4/CS content, the electrical and magnetic properties of WPU‐RGO/ATP‐Fe3O4/CS composites were improved. When the content of RGO/ATP‐Fe3O4/CS was 8 wt%, the electrical conductivity and the saturation magnetic strength of WPU‐RGO/ATP‐Fe3O4/CS composites were 3.1 × 10−7 S·cm−1 and 1.38 emu/g, respectively. WPU‐RGO/ATP‐Fe3O4/CS composites have excellent electrical and magnetic properties.

Tensile behaviour and characterization of epoxy-clay-poly (ethylene terephthalate) nanocomposites

In the present research work, the effect of varying concentration of nanoclay and un-treated/treated polyethylene terephthalate fibers (PET fibers) on tensile strength of nanocomposites was investigated. Response surface methodology (RSM) using Minitab software was used in this investigation. A total 18 experiments with 2 replications each were designed using ‘Extreme Vertices’ design model. Maximum and minimum values for tensile strength were obtained as 43.3 MPa and 26.7 MPa respectively. X-ray diffraction (XRD) analysis revealed that an intercalated structure/morphology was achieved during processing of all nanocomposites. For improvement in interfacial adhesion of PET fibers with other constituents of composite system, alkaline treatment of PET fibers was performed. ∣For alkali treatment, different treatment times and temperatures were selected. This was followed by investigation of tensile behaviour of composites reinforced with surface-modified PET fibers treated under a given condition. SEM analysis of fractured tensile specimens was used to establish structure-property relationship. Fracture surface of tensile specimens of nanocomposites containing untreated PET fibers showed clean fiber surface and fiber pull-out locations; however, nanocomposites containing alkaline treated PET fibers exhibited fiber breakage and rough fiber surface indicating enhanced resistance to crack front growth.

Thermal, Mechanical Properties and Rheological Behavior of Poly(Propylene Carbonate)/Poly(Ethylene Glycol)/Graphene Oxide Nanocomposites

Graphene oxide (GO) is an efficient nanofiller for polymers and a good dispersion of GO in polymer matrix is most important to enhance properties. Poly(propylene carbonate) (PPC)/GO nanocomposite was prepared by a method with solution blending and melt mixing for improvement of GO dispersion. First, GO was prepared using an improved Hummers method. In the solution blending, GO was well dispersed in water and another low molecular weight polymer, poly(ethylene glycol) (PEG), was also dispersed in water, as a dispersion medium for next melt mixing of PPC and GO. Then PPC and PEG/GO was melt-mixed in a HAAKE mixer. The dispersion of GO in PPC matrix and effect of GO content on properties of PPC/PEG/GO nanocomposites was investigated. Results show that tensile strength of nanocomposites with the content of 0.5 wt% GO increased from 17.51 MPa (pure PPC) to 21.61 MPa and elongation at break can be kept high. The complex viscosity, storage and loss modulus is the highest for nanocomposites with the content of 0.5 wt% GO. This illustrated that a lower content of GO can improve the properties of PPC, owing to the good dispersion of GO in PPC matrix. Based on dispersion of GO and chemical structure of PPC, PEG, and GO, the reinforcement mechanism of GO in PPC was analyzed.

Mg improves the distribution of Al2O3 nanoparticles in an Al matrix via solidification

We report the effect of Mg addition on the distribution of a low content of Al2O3 nanoparticles in the Al matrix as well as the mechanical properties of the prepared nanocomposites. The results show that the average grain size was slightly smaller in nanocomposites with Mg than those without. The addition of Mg leads to complete dispersion and uniform distribution of Al2O3 nanoparticles in the Al matrix. The uniform distribution of Al2O3 nanoparticles is contrary to the view that most Al2O3 nanoparticles are pushed to the grain boundary with the low volume fraction of nanoparticles added into the metal melt. MgAl2O4 formed at the interfaces improved the interfacial wetting and bonding between nanoparticles and the Al matrix. The addition of magnesium leads to a significant increase in the elongation of nanocomposites. Orowan strengthening increased the yield strength and tensile strength of nanocomposites with Mg versus those without Mg. The tensile strength and yield strength of nanocomposites with Mg were 265 MPa and 206 MPa, respectively—an increase of approximately 29% and 51% versus Mg-free nanocomposites.

Effect of neodymium‐doped titanium dioxide nanoparticles on the structural, mechanical, and electrical properties of poly(butyl methacrylate) nanocomposites

Nanocomposites based on neodymium‐doped titanium dioxide (Nd‐TiO2)/poly(n‐butyl methacrylate) (PBMA) have been prepared by an in situ polymerization of butyl methacrylate monomer with varying concentrations of Nd‐TiO2 nanoparticles. The resulting nanocomposites have been analyzed by ultraviolet (UV)–Visible spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis, and impedance analyzer (TGA). The results of UV and FTIR spectroscopy have indicated the interaction of nanoparticles with the PBMA matrix. Spherically shaped nanoparticles with an average size of 10–25 nm have been revealed in the TEM and their homogeneous dispersion, and interaction of polymer matrix has been confirmed by SEM and XRD studies. The thermal stability and glass transition temperature of the composites were significantly enhanced by the addition of nanoparticles. The AC conductivity and dielectric properties of nanocomposites have been found to be higher than pure PBMA, and the maximum electrical properties have been observed for 7 wt% composite. The reinforcing nature of the nanoparticles in PBMA has been reflected in the improvement in tensile strength measurements. The result indicated that the tensile strength of nanocomposites have greatly enhanced by the addition of Nd‐TiO2 nanoparticles whereas the elongation at break decreases with the loading of nanofillers. To understand the mechanism of reinforcement, tensile strength values have been correlated with various theoretical modeling. The research has been found to be promising in the development of novel materials with enhanced tensile strength, dielectric constant, and thermal properties, which may find potential applications in energy storage and nanoelectronic devices. J. VINYL ADDIT. TECHNOL., 25:9–18, 2019. © 2018 Society of Plastics Engineers

Evaluation of drilling performances of nanocomposites reinforced with graphene and graphene oxide

The use of graphene (G) and graphene oxide (GO) reinforced nanocomposites have a great importance since G and GO improve the interface conditions of composite materials. However, the effects of G and GO on some mechanical properties and machinability in nanocomposites are still a research topic. In this study, G was converted to GO by Hummers’ method. G and GO nanoparticles were added to epoxy at different ratios and the tensile strengths of nanocomposites were determined. By taking into account, the reinforcement ratio of nanocomposites having the highest tensile strength, epoxy with G and GO, and unreinforced epoxy were added to carbon fiber (CF) fabric by hand lay-up. Thus, fabrication of the carbon fiber-reinforced plastic (CFRP) composite, and the G/CFRP and GO/CFRP nanocomposites was carried out. The effects of the G and GO on the fabricated nanocomposites, and the effect of different drilling parameters (cutting speed and feed rate) on the cutting force, cutting torque, temperature, and delamination factor were investigated. In the drilling of these composites, drills with the different bit point angles and the diameter of 5 mm were used. As a result, it was observed that GO was successfully synthesized, and G and GO positively affected the tensile strength, and GO exhibited a more effective feature than G on the tensile strength. It was also seen that the increase of the cutting speed, feed rate, bit point angle caused the increase in the cutting forces, cutting torque, and delaminations.

Effect of Silica Nanotube Surface Modification on the Physical Properties of Nanocomposites with Poly(methyl methacrylate)

Poly(methyl methacrylate) (PMMA)/silica nanotube (SNT) nanocomposites were prepared by a melt dispersion method using a twin screw extruder and a chloroform-based solvent dispersion method. After removing the template by calcination or organic solvent treatment, the SNT surface was modified by methacryloxypropyl trimethoxysilane (MPMA). The effects of SNT template removal, surface modification, and nanocomposite preparation method on the physical properties of PMMA/SNT nanocomposites were analyzed. The dispersion of SNTs in PMMA was analyzed using transmission electron microscopy. The thermal properties were evaluated using differential scanning calorimetry and thermogravimetric analysis. The mechanical properties of the nanocomposites were analyzed using a universal testing machine and the light transmittance of the nanocomposites was measured using UV-VIS-NIR spectrophotometry. As the SNT increased, the flexural modulus of SNT/PMMA nanocomposites increased. In particular, the surface modified SNT nanocomposite with 5% content by solvent dispersion method showed 49% improvement in flexural modulus compared to virgin PMMA. The tensile strength of nanocomposites decreased with the increase of SNT content. Nanocomposite containing surface modified SNT was higher in tensile strength than that of SNT without surface modification. The dispersion of SNT in the nanocomposite was better by surface modification of SNT, regardless of the preparation method (melt or solvent) of the nanocomposite. However, the light transmittance was more dependent on the SNT template removal method than the SNT surface modification, and ethanol extraction showed higher light transmittance than the calcination method.

Irradiation of poly(vinyl ester)/clay nanocomposites

The effect of electron beam irradiation on pristine poly(vinyl ester) and cured poly(vinyl ester)/clay nanocomposite with different clay contents is studied at irradiation doses ranging from 100 to 1000 kGy at room temperature. Poly(vinyl ester)/clay nanocomposites were prepared with different amounts of organically modified montmorillonite (1, 3, and 5 wt.%) by in situ polymerization method. Morphology properties of synthesized nanocomposites were studied by X-ray diffraction and transition electron microscopy. The irradiation dose up to 500 kGy yields an increase in Young’s modulus and tensile strength of nanocomposites while further irradiation deteriorates the mechanical strength of samples. Irradiation has no considerable influence on the surface hardness of synthesized nanocomposites. Thermogravimetric analysis results reveal the thermal stability of poly(vinyl ester), and its nanocomposites is improved with irradiation up to 500 kGy. However, similar to mechanical perdition at 1000 kGy irradiation, thermal resistance of nanocomposites decreases. The enhancement in mechanical and thermal properties of synthesized nanocomposites is attributed to the cross-linking effect as bonds can be formed directly between the neighbouring chains.

Modeling of tensile strength in polymer particulate nanocomposites based on material and interphase properties

ABSTRACTIn this work, a simple model is presented to determine tensile/yield strength in polymer nanocomposites containing spherical nanofillers based on material and interphase properties. The accuracy of the proposed model is estimated by comparing with the experimental strength of several samples from the literature. In addition, the effects of thickness (t) and tensile strength (σi) of the interphase as well as the radius (R) and volume fraction ( ) of the nanoparticles on the tensile strength are explained according to the proposed model. The high level of nanoparticle strength (more than 100 GPa) commonly leads to overestimates of the tensile strength of nanocomposites, whereas the assumption of correct interphase properties produces accurate calculations. The tensile strength of nanocomposites does not change at σi &lt; 38 MPa, while it increases by 140% at t = 20 nm and σi = 90 MPa. However, a maximum 14% growth in tensile strength is obtained with the optimum values of = 0.04 and R = 10 nm. Therefore, the concentration and size of the nanoparticles have minor effects on the tensile strength of nanocomposites, but the major influences of interphase thickness and strength are pronounced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44869.

Study on the Preparation and Anisotropic Distribution of Mechanical Properties of Well-Aligned PMIA Nanofiber Mats Reinforced Composites

Well-aligned PMIA nanofiber mats were fabricated by electrospinning and then hot-pressing was used to produce PMIA nanofiber mats reinforced PLA matrix by layer-by-layer with the interlayer angles of 0, 45, and 90°. Orthogonal experimental design was employed to fix the effect of the hot-pressing parameters on the tensile strength of nanocomposites, and SEM was used to characterize the broken sections of the nanocomposites after tensile test. The optimized process parameters were achieved of pressure as 1000 Pa, temperature as 180°C, and time as 30 min. The SEM images of broken sections showed that the different laminate forms and the state of bearing load of nanofibers resulted in the different morphologies of broken sections. The break strength of PMIA/PLA nanocomposites with any of interlayer angles at different tensile testing directions was revealed as follows: axial &gt; oblique &gt; transverse, and the initial modulus also showed the same except the angle of 90° with the approach initial modulus at the axial and transverse directions. The maximum tensile strength and modulus of the nanocomposites were 17.12 MPa and 1642.17 MPa, respectively, of the axial tensile testing directions of the interlayer angle of 0°.