Search

The use of antibacterial biodegradable polymers is of great importance nowadays in medical applications. In this manuscript, poly(butylenes adipate-co-terephthalate)/poly(lactic acid) blend-based antibacterial bionanocomposites were prepared by melt-processing. We use organically modified montmorillonite (MMT) and graphene nanoplatelets (GNP) as antibacterial property enhancers which are both processing platelike structure, while ciprofloxacin hydrochloride (CFX·HCl) was chosen as a biocide. Either MMT or GNP increases the antibacterial properties during the whole study and tunes the release of CFX·HCl from the bionanocomposites. This was proven by agar diffusion tests and antimicrobial release measurements. The morphology of the bionanocomposites was conducted by using scanning and transmission electron microscopies, and evidence of exfoliation was observed. Contact angle and water uptake of the bionanocomposites were studied showing hydrophilic performance and more percentage water uptake. The final effect on mechanical and blood compatibility was also investigated. The results reveal excellent possibility of using MMT- and GNP-modified PLA/PBAT polymer blends to tune antibacterial properties for specific biomedical applications. [ABSTRACT FROM AUTHOR]

Recent advances in the cell structure regulation and performances improvement of porous poly(lactic acid) materials (PPMs) are systematically reviewed in this feature article. First, the typical processing methods, including template method, non‐solvent induced phase separation, freeze–drying, and supercritical CO2 foaming, of PPMs are introduced emphatically. Their various cell morphologies by different processing methods are summarized: finger–like, honeycomb–like, fiber–like, through cell, open cell, closed cell, ball–like, and flower–like. Meanwhile, the transformation among different cell morphologies as well as the changes in cell size and cell density, having impact on the performances, is described. Second, the influence of stereo–complex crystals on the cell structure of PPMs is emphatically reviewed. Furthermore, the relationships between cell structure and properties that includes mechanical properties, thermal stability, heat insulation, and hydrophobicity, are elaborated. Eventually, the issues of PPMs worthy of further study are discussed. [ABSTRACT FROM AUTHOR]

Passive radiative cooling technology provides a sustainable way of cooling by the combination of emitting heat to the cold universe and reflecting solar light without any energy input. However, the massive consumption of non‐degradable radiative cooling materials causes resource waste and environmental pollution. Meanwhile, the cooling efficiency can be easily affected by dirt contamination in outdoor environments. Here, by the combination of biomimetic hierarchical structure design and stereo‐complex crystals, a degradable and superhydrophobic (152°) stereo‐complex poly (lactic acid) aerogel with low thermal conductivity (37 mW m–1 K–1), high compression strength (0.1 MPa) and self‐cleaning ability via a simple water‐assisted thermally induced phase separation method is developed. The optimal aerogel has a high sunlight reflection (89%) and strong infrared emissivity (93%) that gets a temperature drop of 3.5 °C during the daytime and 5.8 °C during the nighttime. This aerogel opens an environmentally sustainable pathway to radiative cooling applications. [ABSTRACT FROM AUTHOR]

In this work, poly(ethylene glycol) (PEG)/boron nitride nanosheets (BNNS) masterbatch was prepared by freeze-drying their ultrasonically homogenized aqueous suspension, followed by melt-mixing with poly(lactic acid) (PLA) to fabricate the nanocomposites. The effect of PEG and BNNS on the crystallization behavior of PLA was investigated. The dynamic mechanical properties, thermal conductivity and thermal stability of the nanocomposites were also evaluated. It was found that, under quiescent conditions, PEG and BNNS had a synergistic effect on accelerating the nonisothermal crystallization of PLA. Unexpectedly, under injection molding conditions, the combination of PEG and BNNS had a negative effect on PLA crystallization. This can be ascribed to the plasticizing effect of PEG, which relaxes the orientation of PLA chains and retards flow-induced crystallization. Dynamic mechanical analysis (DMA) showed that the presence of BNNS enhanced the heat resistance of PLA only when PLA was crystallized, while further incorporation of PEG had a negative effect. Nevertheless, simultaneous use of PEG and BNNS had a synergistic effect on enhancing the thermal conductivity of PLA. [ABSTRACT FROM AUTHOR]

[Display omitted] • Higher quenching temperature and longer quenching period facilitate SC crystal formation. • The addition of deionized water to the solvent effectively enhances the formation of SC crystals. • The introduction of carbon nanotubes (CNTs) as a nucleating agent significantly impacts SC crystals formation. The formation of stereo-complex crystals (SC) in porous poly (lactic acid) (PLA) material is intricately linked with improving its comprehensive properties. In this work, the effects of process conditions, solvent composition and additional nucleating agent on SC crystals during the fabrication of porous PLA through thermally-induced phase separation method were studied. Crystallization behavior of SC crystals during the pore-forming process is systematically investigated, revealing that higher quenching temperature and longer quenching period facilitate the formation of SC crystals. Additionally, the addition of deionized water to the solvent effectively enhances SC crystals formation by reducing solution viscosity and prolonging the phase separation time. The highest crystallinity of SC crystals (X SC) can be achieved, reaching 30.6%, when the water content is controlled at 1.6%. Furthermore, the introduction of carbon nanotubes (CNTs) as a nucleating agent exhibits a pronounced effect on the formation of SC crystals. When incorporating a 3 wt% content of CNTs, X SC reaches its peak value at 37.7%. This work is helpful to provide reference for improving mechanical properties and heat resistance of porous PLA, thereby expanding its potential outdoor applications. [ABSTRACT FROM AUTHOR]

In this work, biodegradable poly(lactic acid) (PLA)/Ti3C2Tx MXene nanocomposites were prepared through melt compounding. The roles of MXene in nonisothermal melt and cold crystallization of PLA were explored. The morphology, structure and crystallization behavior were studied using polarized optical microscopy, wide-angle X-ray diffraction and differential scanning calorimetry. For nonisothermal melt crystallization, the presence of MXene increases the crystallinity and shortens the half-crystallization time but does not change the crystallization peak temperature of PLA. For nonisothermal crystallization from the glassy state, the incorporation of MXene decreases the cold crystallization peak temperature and reduces the crystallinity marginally but does not affect the half-crystallization time of PLA. The crystallization kinetics analysis based on the Avrami equation shows that, for both the melt and cold crystallization, the crystallization mechanism is unchanged irrespective of the addition of MXene. The investigation would be useful for understanding the correlation between processing and properties of PLA/MXene nanocomposites. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) inherently shows the distinct brittleness at room temperature, which is a major drawback limiting its practical applications. Great efforts have been done to improve the toughness by adding high content of flexible polymers or low content of nanoparticles, which is often at the expense of tensile strength. In this work, supertoughened PLA blend with high elongation at break (247.7%) containing low content of poly(ethylene oxide) (PEO) (8%) was directly fabricated by melt extrusion method. Interestingly, its tensile strength and modulus are only slightly decreased (<25%). The reasons for the balanced mechanical property can be understood as follows: I) The increasing mobility of amorphous chains of PLA due to the plasticizing effect of PEO. II) The strengthening effect of mesophase can hinder tensile strength to be severely sacrificed. III) The rod-like PEO phase can initiate more crazes and further prevents them from developing into cracks, allowing effective energy dissipation. This study proposes a facile but efficient strategy to fabricate PLA blends containing low content of PEO with balanced mechanical property, which would provide a clue for toughening other brittle thermoplastics. [Display omitted] • PLA blend with balanced mechanical property is directly prepared by melt extrusion. • A low content of PEO can realize the supertoughness of PLA. • The tensile strength and modulus are only slightly decreased. • Mesophase and rod-like phase morphology are keys to supertoughness. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is one of the most promising bio-based polyester with great potential to replace for the petroleum-based polymers, which can significantly reduce greenhouse gas emissions. However, the inherent brittleness of PLA seriously restricts its broad applications. Herein, PLA/poly(ε-caprolactone) (PCL)/ethylene methyl acrylate-glycidyl methacrylate (EMA-GMA) ternary blends with different phase structures were prepared through reactive blending. The reactions between the epoxy groups of EMA-GMA and the carboxyl and hydroxyl end groups of PLA and PCL and were evidenced from the Fourier transform infrared spectroscopy, dynamic mechanical analysis and rheological results. The atomic force microscopy (AFM) images clearly revealed the formation of stack structure of the PCL and EMA-GMA minor phases in PLA/PCL/EMA-GMA (80/15/5) blend, and core-shell particle structures in PLA/PCL/EMA-GMA (80/10/10) and (80/5/15) blends. In terms of elongation at break and impact toughness, PLA/PCL/EMA-GMA (80/5/15) blend presents the best properties among all the compositions. Moreover, it also behaved excellent stiffness-toughness balance. The toughening mechanism can be ascribed to the formation of core-shell structure and the existence of interfacial adhesion in the ternary blends. This work can provide guide for the preparation and design of PLA-based partially renewable supertough materials that can compete with conventional petro-derived plastics. • PLA/PCL/EMA-GMA ternary blends with different phase structures were fabricated. • Reactions of EMA-GMA with PLA and PCL were evidenced. • AFM images clearly revealed stack or core-shell structures of minor phases in PLA. • PLA/PCL/EMA-GMA (80/5/15) shows the best toughness and stiffness-toughness balance. • Core-shell structure of minor phases is mainly responsible for toughening of PLA. [ABSTRACT FROM AUTHOR]

High-toughness biodegradable poly(lactic acid) (PLA) has always been intensively pursued on the way of replacing traditional petroleum-based plastics. Regulating microstructures to achieve self-toughening holds great promise due to avoidance of incorporating other heterogeneous components. Herein, we propose a straightforward and effective way to tailor microstructures and properties of PLA through melt-stretching and quenching of slightly crosslinked samples. The melt stretching drives chains orientation and crystallization at high temperature, while the quenching followed can freeze the crystallization process to any stage. For the first time, we prepare a type of transparent and low-crystalline PLA filled with rod-like β-form shish, which displays an outstanding tensile toughness, almost 17 times that of the conventional technique-processed one. This mechanical superiority is enabled by an integration of high ductility due to oriented chain network, and high tensile stress endowed by nanofibrous filler's role of β-form shish. Furthermore, the mechanically toughened PLA is demonstrated to generate the richest micro-cracks and shear bands under loading, which can effectively dissipate the deformational energy and underlie the high toughness. This work opens a new prospect for the bottom-up design of high-performance bio-based PLA materials that are tough, ductile and transparent by precise microstructural regulation through scalable melt processing route. • Melt stretching and quenching were combined to regulate microstructures of PLA. • High-toughness PLA composed of oriented chain network and β-form shish was fabricated. • Oriented chain network provided ductility and β-form shish imparted high tensile stress. • Numerous micro-cracks and shear bands were formed in toughened PLA under tensile deformation. [ABSTRACT FROM AUTHOR]

The knowledge about the influence of the electron beam (EB) radiation dose on the chemical and physical changes of polymers is critical either for sterilization purpose or materials modification. In this work, the effect of EB irradiation dose ranging 25–100 kGy on the properties of commercial poly(lactic acid) (PLA), poly(butylene adipate- co -terephthalate) (PBAT) and their blends was compared. The samples of about 0.5 mm in thickness were prepared by hot pressing. The changes in molecular weight, yellow index, thermal and mechanical properties were evaluated. The main findings are that a severe reduction in the glass transition and melting temperatures as well as the mechanical properties of PLA occurs when subjected to higher doses of EB irradiation, which can be ascribed to irradiation-induced decrease in molecular weight; while the effect of EB irradiation on the molecular weight and mechanical properties of PBAT and PLA/PBAT blends is ignorable. [ABSTRACT FROM AUTHOR]

Poly(ε-caprolactone)/poly(lactic acid) (PCL/PLA) blends are promising biomaterials with biodegradable characteristics. However, poor compatibility of the two components may lead to undesirable mechanical properties. In this work, the effect of combining carboxyl multi-walled carbon nanotubes (CNTs) and organically modified montmorillonite (MMT) on the morphology and properties of PCL/PLA blend was investigated. The morphological observations and rheological analysis showed that exfoliated MMT platelets enhanced interfacial adhesion of the two phases, whereas CNTs formed a percolating network in PCL matrix. The addition of CNTs/MMT (0.5 wt%: 0.5 wt%) led to an increase by 137.4% in elongation at break, 79.6% in tensile strength, and 14 °C in decomposition temperature without sacrificing its rigidity apparently for the PCL/PLA matrix. Obvious synergistic effect was demonstrated in comparison to the blends containing single nanofiller. This study demonstrated that combining CNTs and MMT is a facile way to preparing immiscible PCL/PLA blends based nanocomposites with interesting structure and properties. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a biodegradable and biocompatible polyester derived from renewable resources like corn starch, presenting great potential in clinical applications like tissue engineering, implants and drug delivery systems. However, the intrinsic brittleness restricts its real applications. In this work, PLA nanocomposites were prepared by incorporating a small amount of carboxyl functionalized multi-walled carbon nanotubes (CNTs) and surface compatabilized montmorillonite (MMT) via technologies of freeze-drying and masterbatch-based melt blending. In the resulting nanocomposites, a well-distributed nano-filler network with microstructures of 1-D CNTs/2-D MMT platelets is formed favored by the enhanced interfacial interaction between the organic modified fillers with PLA matrix. Thanks to the well dispersed organic modified nanofillers, a large number of microcracks and extremely stretched PLA matrix are induced during tensile process, dissipating amounts of energy. As a result, the filler networks reinforce PLA with increment of 19% in modulus, remarkably increase by 13.8 times in toughness relative to PLA control without sacrificing strength. Thus, the PLA nanocomposites with excellent properties prepared through the facile and effective route possess broad prospect in biomedical applications. [ABSTRACT FROM AUTHOR]

• Freeze-dried PEO/GNP masterbatch was melt-mixed with PLA and PBAT. • Adding 1 wt% PEO reduces greatly the complex viscosity of the nanocomposites. • PEO effectively promotes the dispersion of GNP in dispersed PBAT phase. • PEO greatly enhances the toughness and thermal stability of PLA/PBAT/GNP. • Effect of the molecular weight of PEO was evaluated. Graphene nanoplatelets (GNP) is a relative new nanofiller used to tailor the morphology and properties of immiscible polymer blends. However, the self-agglomeration of GNP in the polymer matrix prevents the improvement in mechanical properties. In this work, a water-soluble polymer, poly(ethylene oxide) (PEO), was introduced to improve the dispersion of GNP in biodegradable immiscible poly(lactic acid) (PLA)/poly(butylene adipate- co -terephthalate) (PBAT) blends. PLA/PBAT based nanocomposites were prepared by melt-mixing PLA and PBAT with freeze-dried PEO/GNP masterbatch. It is found that a small amount of PEO incorporation (1 wt%) enhances the dispersion of GNP in the dispersed PBAT phase and reduces the complex viscosity of the systems significantly. Moreover, the presence of PEO enhances greatly the toughness and thermal stability of PLA/PBAT/GNP nanocomposites. The effect of the molecular weight of PEO was also addressed. [ABSTRACT FROM AUTHOR]

• Cylindrite of Poly(lactic acid) with inner and outer layers was first observed. • The critical shear conditions of hierarchical cylindrite formation were given. • Formation mechanism of shear induced crystallization, especially the hierarchical cylindrite was described. • The relationships between inner layer thickness and shear affected region were quantified. The shear-induced interfacial crystallization structure and morphology of poly(lactic acid) (PLA) was investigated by pulling a single glass fiber (GF) at different velocities and over different durations at 120 °C. The hierarchical cylindrites with two layers were found when the GF pulling speed or pulling time arrived at a critical value according to the polarized optical microscopy (POM) results. Beyond the critical value, the cylindrite thickness of the inner layer sharply increased and finally reached saturation at 18.5 μm along the radial direction. The POM results were consistent with the value of the shear affected range assessed by the thermomechanical model (Monasse, 1992). The relative degree of crystallinity (A 922 / A 956), based on polarized Fourier transform infrared spectroscopy (FTIR), increased with fiber pulling speed, and then reached a plateau at 1.68, corresponding to the critical speed. The spatial competitiveness at the fiber surface is the main factor responsible for the formation mechanism of the cylindrite, especially the hierarchical cylindrite. [ABSTRACT FROM AUTHOR]

Abstract The self-assembly behavior of N,N′,N ″-tricyclohexyl-1,3,5-benzenetricarboxylamide (BTCA) and its nucleating effect on poly(lactic acid) (PLA) crystallization were studied by differential scanning calorimetry and polarized optical microscopy. The effect of melting temperatures (T f) from 190 to 240 °C, BTCA concentrations from 0 to 0.5 wt%, and cooling rates from 2.5 to 20 °C/min was investigated. It was found that, when T f was 240 °C, BTCA could dissolve completely in PLA matrix, and then self-assemble into supermolecular frameworks upon decreasing temperature. The core findings are as follows: (1) for the two-step crystallization, the half-crystallization time of PLA showed a bell shaped dependence on the pre-crystallization temperatures of BTCA, which was higher than that without pre-treatment; (2) for nonisothermal crystallization, the crystallization peak temperature of PLA presented a bell shaped dependence on the concentration of BTCA at each rate. Meanwhile, the BTCA concentration, which corresponded to the maximum crystallization rate of PLA, shifted to higher value with the increase of cooling rate. The observations were discussed in term of the effective nucleating surface area of BTCA. Graphical abstract Image 1 Highlights • We examined the nucleating effect of BTCA on PLA crystallization. • PLA crystallization presents a bell-shaped dependence on BTCA concentration. • Optimized BTCA concentration for PLA crystallization depends on cooling rate. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA)/poly(ethylene oxide) (PEO) blends nucleated by a self-assembly nucleating agent, N,N′,N″-tricyclohexyl-1,3,5-benzenetricarboxylamide (BTCA), were prepared by melt blending. The crystallization behavior and mechanical properties of the materials were investigated by differential scanning calorimetry, polarized optical microscopy, wide-angle X-ray diffraction, dynamic mechanical analyzer and tensile testing. It was found that PEO had a synergistic effect together with BTCA on promoting PLA crystallization, besides its toughening effect on the material. Moreover, BTCA revealed prominent reinforcement effect on both neat PLA and PLA/PEO blends in the glass transition region and above, indicating the improvement on the heat resistance of the materials. [ABSTRACT FROM AUTHOR]

Structural evolution of poly(lactic acid) (PLA) upon uniaxial stretching was studied with in-situ polarized infrared spectroscopy measurements, and its structural change affected by annealing was also investigated. Band shifting was used to reflect the structural ordering process. It was found that the band at 1302 cm −1 always moves to low wavenumbers before crystallization, indicating the occurrence of intermolecular packing ordering. However, the band at 869 cm −1 shifts to high wavenumbers, which is related to the transition from the amorphous phase to the ordered phase. Interestingly, during stretching, the shifting for the band at 1302 cm −1 always occurs before that for the lower wavenumber band, whereas these two band shifts take place simultaneously under annealing. Based on the different characteristics of the structural evolution under stretching and annealing processes, a critical temperature was found at around 63 °C, which influences the effect weight of kinetic and thermodynamic factors to the crystallization behavior. The effect of the drawing temperature on crystallization and mechanical property of PLA films was also analyzed. [ABSTRACT FROM AUTHOR]

Applying flow to stimulate the shish-kebab formation in semi-rigid poly(lactic acid) (PLA) is far from mature compared to that in flexible polyolefins, which waits to be solved for both academia and industry. Herein, we conduct a systematic investigation on the flow-induced crystallization of lightly crosslinked PLA melt by a combination of extensional rheology and in situ synchrotron wide and small-angle X-ray scattering. With Hencky strain above a critical value of 1.5–2.0, abundant shish-kebabs with high orientation and high regularity are identified to form, which leads to not only tremendous acceleration of PLA crystallization kinetics but also superb heat tolerance of finally solidified sample. With an affine deformation assumption, the generation of shish-kebabs is recognized to require the entanglement network deformation in crosslinked component chains reaching 67% of its maximum elongation ratio, much higher than that reported in polyethylene. In addition, we have confirmed a heterogeneous spatial distribution of crystalline polymorphs in shish-kebab body due to its morphological duality. The β-form contributes mainly to the central shish originating from strongly stretched crosslinked component chains, while the α/α′-form to the lamellar kebab from moderately orientated free chains. Then a close relationship between chains deformation, crystalline polymorphs, crystal morphology and material property is well established. This study has disclosed that imposing melt extension to lightly crosslinked PLA can result in extraordinary crystallization capacity of PLA material comparable to that of flexible polyolefins, showing potential significance for guiding the industrial processing. Image 1 • Extension with Hencky strain above 1.5–2.0 induces the massive formation of shish-kebabs. • Heterogeneous spatial distribution of crystalline polymorphs is confirmed in shish-kebab body. • Formation of shish-kebabs with high interlocking provides PLA with superb heat tolerance. • Relationship between chains deformation, crystalline polymorphs, crystal morphology and material property is elaborated. [ABSTRACT FROM AUTHOR]

Microphase dispersions and interface interactions are crucial for high performance polymer nanocomposites. However, it remains a challenge to evaluate their effects quantitatively. In this work, poly(ε-caprolactone) (PCL)/poly(lactic acid) (PLA)/montmorillonite (MMT) nanocomposites were chosen as the model nanocomposites, and the effect of MMT on the microphase dispersions and interface interactions were studied and compared with PCL/PLA blends. Using the atomic force microscope (AFM) based nanomechanical mapping, the interface interactions and microphase evolution under tensile were visualized. The Young's moduli map shows a significantly increased interface width of 91.0 ± 15.3 nm for PCL/PLA/MMT nanocomposites compared with 28.7 ± 4.2 nm for PCL/PLA blends. Moreover, the morphology evolution and the onsite changes of microscopic mechanical properties for PCL/PLA/MMT nanocomposites under tensile were visualized and compared with PCL/PLA blends. The results can therefore provide more insights into understanding the complicated toughening mechanism of ternary nanocomposites. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) was introduced to improve the dispersion of graphene nanoplatelets (GNPs) in poly (lactic acid) (PLA) matrix. GNPs were dispersed into PEO aqueous solution and freeze-dried to form PEO/GNPs masterbatch, followed by melt-mixed with PLA to prepare the nanocomposites. Three grades of PEO with different molecular weights were evaluated. It is found that adding very low loading of PEO (1 wt%) enhances the dispersion of GNPs in PLA matrix, resulting in remarkable improvement in elongation at break of PLA/GNPs without obviously sacrificing its modulus and tensile strength. Meanwhile, PEO reveals a synergistic effect with GNPs in promoting PLA crystallization. Moreover, GNPs enhances significantly the thermal stability of PLA, while further addition of PEO does not apparent compromise this effect. In addition, PEO with low molecular weight presents the best effect in improving the properties of PLA/GNPs nanocomposites. • Freeze-dried PEO/GNPs masterbatch was melt-mixed with PLA. • PEO effectively promotes the dispersion of GNPs in PLA matrix. • PEO enhances the toughness of PLA/GNPs. • PEO enhances the crystallization ability of PLA/GNPs. • Effect of the molecular weights of PEO was addressed. [ABSTRACT FROM AUTHOR]

Poly(lactic acid)/poly(ε-caprolactone) (PLA/PCL) blends are among the most widely investigated biomaterials for tissue engineering scaffolds. Incorporating carboxylic multi-walled carbon nanotubes (MWCNTs) into the blend can further tune the microphase distribution and interface adhesion which conversely dominates the micromechanical properties. In this work, atomic force microscope (AFM) based quantitative nanomechanical measurements were applied on PLA/PCL/MWCNTs bionanocomposites for gaining knowledge at the nanoscale. Results show that MWCNTs are mainly dispersed in the PCL phase which is adjacent to the PLA phase. The microphase structures and the onsite microscopic Young's moduli distributions have significant changes with the introduction of MWCNTs. No obvious intermediate layer in the PLA/MWCNTs and PCL/MWCNTs interfaces is observed in the Young's moduli map, indicating weak interactions in the polymer/MWCNTs interface. Moreover, microscopic structure-property relationships of PLA/PCL/MWCNTs nanocomposites were discussed and correlated to the macroscopic mechanical properties. A better understanding of these properties would be helpful in tailoring the PLA/PCL based bionanomaterials for applications in tissue engineering scaffolds, where the nanomechanical information is critical. • The dispersion state of MWCNTs in PLA/PCL/MWCNTs composites was visualized by AFM. • The introduction of MWCNTs significantly affected the morphology of the nanocomposites. • New method nanomechanical mapping was presented to characterize the microscopic mechanical properties. • Microscopic Young's moduli distribution together with interface interactions of the nanocomposites was investigated. • The microscopic mechanical properties of the nanocomposites were related to their macroscopic mechanical properties. [ABSTRACT FROM AUTHOR]