Polylactide/graphite nanosheets/MWCNTs nanocomposites with enhanced mechanical, thermal and electrical properties

In this study, we have prepared a series of novel biodegradable polymer [polylactide (PLA)]-based nanocomposites using graphite nanosheets (GNs) and multi-walled carbon nanotubes (MWCNTs) by solution-blending technique and investigated their morphologies, structures, thermal stabilities, mechanical and dielectric properties, and electrical and thermal conductivities. Before preparation of the PLA/GNs/MWCNTs nanocomposites, the raw GNs used were endured a rapid expansion by thermal treatment. Temperature of this treatment had some obvious impacts on morphological changes of graphite nanosheets which were verified by means of scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. Resultant nanocomposites were characterized and evaluated by means of SEM, XRD, thermal conductivity measurements, tensile and impact tests, thermogravimetric analysis and dielectric measurements. Results obtained in this study indicated that thermal-expanded GNs in the presence of MWCNTs facilitate the formation of an appropriate conductive network in PLA matrix which resulted in a relatively low percolation threshold for thermal and electrical conductions of PLA/GNs/MWCNTs nanocomposites. Significant improvements in thermal and electrical conductivities, thermal stability and mechanical properties of PLA/GNs/MWCNTs nanocomposites obtained through the presence of both nanoparticles in PLA matrix were associated with their good co-dispersion and co-reinforcement effects. The macroscopic properties of nanocomposites were found to be strongly dependent on their components, concentrations, dispersion, and the resulted morphological structures.     

The effect of silica nanoparticles and carbon nanotubes on the toughness of a thermosetting epoxy polymer

Silica nanoparticles and multiwalled carbon nanotubes (MWCNTs) have been incorporated into an anhydride‐cured epoxy resin to form “hybrid” nanocomposites. A good dispersion of the silica nanoparticles was found to occur, even at relatively high concentrations of the nanoparticles. However, in contrast, the MWCNTs were not so well dispersed but relatively agglomerated. The glass transition temperature of the epoxy polymer was 145°C and was not significantly affected by the addition of the silica nanoparticles or the MWCNTs. The Young's modulus was increased by the addition of the silica nanoparticles, but the addition of up to 0.18 wt % MWCNTs had no further significant effect. The addition of both MWCNTs and silica nanoparticles led to a significant improvement in the fracture toughness of these polymeric nanocomposites. For example, the fracture toughness was increased from 0.69 MPam^1/2 for the unmodified epoxy polymer to 1.03 MPam^1/2 for the hybrid nanocomposite containing both 0.18 wt % MWCNTs and 6.0 wt % silica nanoparticles; the fracture energy was also increased from 133 to 204 J/m². The mechanisms responsible for the enhancements in the measured toughness were identified by observing the fracture surfaces using field‐emission gun scanning electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Benzoxazine-functionalized multi-walled carbon nanotubes for preparation of electrically-conductive polybenzoxazines

Functionalization of multi-walled carbon nanotubes (MWCNTs) has been carried out using benzoxazine-containing compound (BPA-FBz) and polymer (PFBz) as modifiers through Diels–Alder reaction. The benzoxazine-functionalized MWCNTs (MWCNT-FBz and MWCNT-PFBz) have been characterized with Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analyzer, and high-resolution transmission electron microscopy. MWCNT-FBz and MWCNT-PFBz are thermally cross-linkable nanomaterials and could be fabricated with press molding and other thermal-forming processes. The cross-linked pellets of MWCNT-FBz and MWCNT-PFBz show surface electrical conductivities of 0.05 S cm^?1. Moreover, nanocomposites have also been prepared from BPA-FBz and MWCNT-FBz. The nanocomposites have shown high electrical conductivities (about 7 × 10^?5 S cm^?1) and good mechanical strength. The attractive properties have been attributed to the good compatibility between the polybenzoxazine matrix and MWCNT-FBz, as the benzoxazine groups of MWCNT-FBz could copolymerize with BPA-FBz in the preparation of nanocomposites.     

Influence of nanoclays on electrical and morphological properties of thermoplastic polyurethane/multiwalled carbon nanotube/clay nanocomposites

Nanocomposites of thermoplastic polyurethanes (TPUs), multiwalled carbon nanotubes (MWCNTs) and clays were prepared via melt processing using polyether‐ and polyester‐based TPUs, MWCNTs, and organically modified nanoclays (Cloisite C30B and C25A). Coaddition of clays and MWCNTs to TPU nanocomposites increased their electrical conductivities above those without any clay. Nanoclay alone is shown to produce no effect on electrical conductivity. TEM results show that the coaddition of nanoclay affects the nanocomposite morphology by changing the MWCNT distribution. Clay C25A and MWCNTs were observed to form network structures in the nanocomposites, resulting in improved electrical conduction. Interaction between MWCNTs and clays as well as an increase in nanocomposite viscosity caused by the coaddition of clays may influence the morphology change. Most of the nanocomposites containing both MWCNTs and clay exhibited higher dielectric constants, indicating higher electrical conductivities. Tensile properties investigations confirmed the reinforcing effects of the MWCNTs and clays. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Evaluation of structural,optical and dielectric properties of MWCNT-BaTiO3/silica ceramic nanocomposites

In this research, MWCNT-BaTiO₃/silica nano-composites were synthesized and analyzed at different MWCNTs loadings (2, 4, 6, and 8% wt). Utilizing the different concentrations of MWCNTs, the optical responses of MWCNT-BaTiO₃/silica nanocomposite were investigated. For this purpose, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were used. Using the Kramers-Kronig method, the refractive index and dielectric coefficient of MWCNT-BaTiO₃/silica nanocomposites were analyzed. Results clearly revealed that the higher incorporation of MWCNTs in nanocomposites led to more strong responses in the real parts of both refractive index and dielectric coefficient. Finally, the transversal (TO)/longitudinal (LO) phonon frequencies shifted to the blue wavenumbers by decreasing the amount of MWCNTs in MWCNT-BaTiO₃/silica nanocomposite.     

多壁碳纳米管/聚酰亚胺复合材料制备及其性能研究

聚酰亚胺的前聚体,聚酰胺酸,是通过4,4-二氨基二苯醚(ODA)与3,3,4,4二苯甲酮四羧酸二酐(BTDA)反应制备的。未改性的、酸改性和胺改性的多壁碳纳米管(MWCNT)被分别地单独加入到聚酰胺酸溶液中,并加热至300℃,从而制成聚酰亚胺/碳纳米管复合材料。扫描型电子显微镜(SEM)和透射电子显微镜(TEM)的显微照片表明,酸改性的多壁碳纳米管和胺改性多壁碳纳米管在聚酰亚胺基体中被均匀一致地分散开。通过对酸和胺改性的多壁碳纳米管MWCNTS对多壁碳纳米管/聚酰亚胺复合材料的表面和体积电阻率的影响进行了研究。了解到该纳米复合材料的表面电阻率ITES从1.28×10^(15)Ω/cm^(2)(纯聚酰亚胺),降到7.59×10^(6)Ω/cm^(2)(26.98%的未改性的多壁碳纳米管含量)。除此之外,添加多壁碳纳米管影响了纳米复合材料的玻璃化转变温度。改性多壁碳纳米管意义就是提高了纳米复合材料的机械性能。多壁碳纳米管/聚酰亚胺复合材料的拉伸强度从10^(2)MPa(纯的聚酰亚胺)增加到134 MPa(6.98%酸改性多壁碳纳米管/聚酰亚胺复合材料)。     

Thermal‐Insulation,Electrical, and Mechanical Properties of Highly‐Expanded PMMA/MWCNT Nanocomposite Foams Fabricated by Supercritical CO2 Foaming

Foaming behavior of poly(methyl methacrylate) (PMMA)/multi‐walled carbon nanotubes (MWCNTs) nanocomposites and thermally‐insulating, electrical, and mechanical properties of the nanocomposite foams are investigated. PMMA/MWCNT nanocomposites containing various amounts of MWCNTs are first prepared by combining solution and melt blending methods, and then foamed using CO₂. The foaming temperature and MWCNT content are varied for regulating the structure of PMMA/MWCNT nanocomposite foams. The electrical conductivity measurement results show that MWCNTs have little effect on the electrical conductivity of foams with large expansion ratio. Thermal conductivities of both solid and foamed PMMA/MWCNT nanocomposites are measured to evaluate their thermally insulating properties. The gas conduction, solid conduction, and thermal radiation of the foams are calculated for clarifying the effects of cellular structure and MWCNT content on thermal insulation properties. The result demonstrates that MWCNTs endowed foams with enhanced thermal insulation performance by blocking thermal radiation. Moreover, the compressive testing shows that MWCNTs improve the compressive strength and rigidity of foams. This research is essential for optimizing environmentally friendly thermal insulation nanocomposite foams with enhanced thermal‐insulation and compressive mechanical properties.     

Remarkable change in the broadband electrical behavior of poly(vinylidene fluoride)–multiwalled carbon nanotube nanocomposites with the use of different processing routes

Poly(vinylidene fluoride) (PVDF) nanocomposites have plenty of applications in the electronic realm. In this study, we produced nanocomposites based on PVDF and multiwalled carbon nanotubes (MWCNTs), with various MWCNT loadings, using three different processing routes: solution mixing, melt mixing, and electrospinning. The broadband electrical behavior of these nanocomposites was studied and compared via impedance spectroscopy. The morphologies of the nanocomposites were characterized by transmission electron microscopy and scanning electron microscopy. The results reveal that the electrical behaviors of the samples were completely different according to the processing route used. Solution mixing was the most suitable method for producing nanocomposites with the highest conductivities, at low MWCNT loadings, whereas electrospinning was the most suitable method for producing nanocomposites with the lowest dielectric permittivity. These differences were attributed to the different arrangements of the MWCNTs caused by the different processes. Although the solution-mixed samples exhibited long and twisted MWCNTs, the melt-mixed samples had shorter MWCNTs, and the electrospun samples had MWCNTs embedded and aligned inside the insulating polymer nanofibers. Thus, these results project a vast horizon for tailoring the structure and thereby the broadband electrical behavior of PVDF–MWCNT nanocomposites for different types of applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47409.     

The effect of multiwall carbon nanotubes on the properties of room temperature-vulcanized silicone adhesives

The effects of surface-functionalized and pristine multiwall carbon nanotubes (MWCNT) on the bulk and adhesion properties of silicone nanocomposites were investigated. The MWCNTs surface functionalization was carried out by silanization of methacryloxy or vinyl-based silanes. The nanocomposites were prepared using solvent mixing which enhanced distribution and dispersion of the MWCNTs in the high-viscosity silicone matrix. The quality of dispersion was evaluated using scanning electron microscopy (SEM) indicating good dispersion state. It was found that the optimal concentration of both treated and untreated MWCNTs in the nanocomposites was 1 wt.%. Above this threshold value, the nanocomposites properties were reduced. Furthermore, the silane treatment of the MWCNTs was proven to be an effective process that resulted in a significant increase in the nanocomposites properties compared to the neat polymer, leading to higher storage modulus simultaneously with up to 27% improvement in the tensile strength and elongation, 20–30% reduction in the thermal expansion coefficient, 220–300% enhancement in crystallinity (enthalpy of fusion), and up to 56% improvement in the lap shear strength. SEM analysis indicated that significant changes in the fracture morphologies occurred due to higher energy absorption in the case of silane-treated MWCNTs. It was concluded that incorporation of silane-treated MWCNTs is an effective route to reinforce and increase the toughness of silicone-based adhesives.     

Structural assembly effects of Pt nanoparticle–carbon nanotube–polyaniline nanocomposites on the enhancement of biohydrogen fuel cell performance

In this work, we designed various polyaniline (PANI) nanocomposites with platinum (Pt) nanoparticle-decorated multi-walled carbon nanotubes (MWCNTs), employed them as anodic catalysts, and studied their structural assembly effects with regard to enhancing biohydrogen fuel cell performance. Of two proposed structures, the PANI/Pt/MWCNTs multilayer nanocomposites showed superior electrocatalytic activities in the hydrogen oxidation reaction and in fuel cell power density relative to the Pt/MWCNTs@PANI core–shell design. These enhancements were attributed to the active interface formed between the Pt nanoparticles and polyaniline nanofibers, where the higher electronic and ionic conductivities of the thin PANI nanofiber layers in contact with Pt active sites were better than with the PANI bound Pt/MWCNTs. We also investigated the change in the electronic state of the composites and the charge-transfer rate caused by varying the structural assembly. Finally, the role of each catalyst component was examined to understand its individual effect on fuel cell performance and to understand its structural assembly effect on enhanced power density.     

Preparation and properties of multi‐walled carbon nanotubes/carbon fiber/epoxy composites

Multi‐walled carbon nanotubes/carbon fiber (MWCNTs/CF) hybrid fillers are employed to prepare MWCNTs/CF/epoxy composites. Results reveal that a great improvement of the thermal conductivities of the epoxy composites with the addition of MWCNTs/CF hybrid fillers, and the thermal conductivity of the MWCNTs/CF/epoxy composites is 1.426 W/mK with 8 vol% treated MWCNTs/CF hybrid fillers (5 vol% MWCNTs + 3 vol% CF). Both the flexural and impact strength of the MWCNTs/CF/epoxy composites are increased firstly, but decreased with the excessive addition of MWCNTs. The flexural and impact strength of the MWCNTs/epoxy composites are optimal with 2 vol% MWCNTs. For a given MWCNTs/CF hybrid fillers loading, the surface treatment of MWCNTs/CF hybrid fillers can further increase the thermal conductivities and mechanical properties of the MWCNTs/CF/epoxy composites. POLYM. COMPOS., 35:2150–2153, 2014. © 2014 Society of Plastics Engineers     

Synthesis of Silica Decorated MWCNTs for Field Emission Property

A novel route to nanocomposites containing surface modified multiwalled carbon nanotubes (MWCNTs) by silica thin film is reported. The effect of chemical oxidation on the surface of MWCNTs by using different acid-treatments is studied.The acidic processes are characterized by Raman spectroscopy, thermogravimetry analysis, scanning electron microscopy, and transmission electron microscopy. MWCNTs can be coated homogeneously with silica film by using tetraethoxysilane (TEOS)as a precursor in a sol-gel process. Varying the shell thickness of amorphous silica coating layers on MWCNTs exhibits excellent thermal stability, reliability, and lifetime of field emission properties, especially down to less than 10 nm.     

Polysiloxane/multiwalled carbon nanotubes nanocomposites and their applications as ultrastable,healable and superhydrophobic coatings

Superhydrophobic coatings with high water contact angles, ultralow sliding angles, excellent stability and good healing capability were prepared by spray-coating the homogeneous suspensions of the fluorine-free polysiloxane/multiwalled carbon nanotubes (POS/MWCNTs) nanocomposites onto various substrates and cured for a period of time. The nanocomposites were synthesized by hydrolytic co-condensation of n-hexadecyltriethoxylsilane and tetraethoxysilane in the presence of acid activated MWCNTs. The nanocomposites composed of POS-modified MWCNTs and free POS are highly dispersible in various alkanes and arenes. The nanocomposites and their coatings were characterized using a wide range of electron microscopy and other analytical techniques. In addition, the effects of various parameters, e.g., acid activation of MWCNTs, diameter of MWCNTs, spray-coating density and annealing temperature, on superhydrophobicity and morphology of the coatings were investigated. Moreover, the stability and healing capability of the coatings were studied. The coatings show negligible change in CAs and maintain low SAs after various harsh stability tests, e.g., intensive sand abrasion from a height of 300 cm. Also, the slightly damaged coatings are healable with the help of toluene and annealing. The mechanisms for the excellent stability and good healing capability were proposed. The ultrastable, healable and superhydrophobic POS/MWCNTs coatings are very promising for various practical applications.     

Silane Modification of Carbon Nanotubes and Preparation of Silane Cross‐Linked LLDPE/MWCNT Nanocomposites

The objective of this study is to investigate the effects of carbon nanotube (CNT) content, surface modification, and silane cross‐linking on mechanical and electrical properties of linear low‐density polyethylene/multiwall CNT nanocomposites. CNTs were functionalized by vinyltriethoxysilane to incorporate the ─O─C2H5 functional groups and were melt‐blended with polyethylene. Silane‐grafted polyethylene was then moisture cross‐linked. Silanization of CNT was confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and EDX analysis. Hot‐set test results showed that silane cross‐linking of polyethylene and incorporation of modified CNTs into polyethylene led to an increase in cross‐linking density and the number of entanglements resulting in a decrease in elongation. It was found that the addition of pristine multiwall carbon nanotubes (MWCNTs) and functionalized MWCNTs does not affect silane cross‐linking density. Silane modification resulted in a stronger adhesion of the silane cross‐linked LLDPE to silanized MWCNTs according to scanning electron microscopy micrographs. Additionally, the electrical tests revealed that the silane modification of CNTs results in an improvement in electrical properties of nanocomposites, while silane cross‐linking will not have an effect on electrical properties. Rheological properties of MWCNT/LLDPE nanocomposites have been studied thoroughly and have been discussed in this study. Moreover, according to TGA test results, modification of the MWCNTs led to a better dispersion of them in the LLDPE matrix and consequently resulted in an improvement in thermal properties of the nanocomposites. Crystallinity and melting properties of the nanocomposites have been evaluated in detail using DSC analysis. J. VINYL ADDIT. TECHNOL., 26:113–126, 2020. © 2019 Society of Plastics Engineers     

Iron/cobalt-SBA-16 cubic mesoporous composites as catalysts for the production of multi-walled carbon nanotubes

A series of catalysts containing iron and cobalt nanoparticles supported on a highly ordered mesoporous cubic Im3m silica (SBA-16) were prepared by wet impregnation and used for the production of multi-walled carbon nanotubes (MWCNTs) by catalytic chemical vapor deposition (CCVD) of acetylene. The catalysts were characterized by low- and wide-angle X-ray diffraction, N₂ physisorption analysis at 77 K and transmission electron microscopy to study the influence of different metal loading and impregnation time on the CCVD process. Quality and morphology of the MWCNTs was assessed by transmission and scanning electron microscopy, whereas thermal analysis was used to estimate the amount of CNTs produced. It was found that the nanocomposites are catalytically active with particular reference to samples with relatively high metal loading, and are stable under the conditions adopted for the CNT production by the CCVD process.     

Surface modification of MWCNT and its influence on properties of paraffin/MWCNT nanocomposites as phase change material

Multiwalled carbon nanotubes (MWCNTs) were modified by an organo-silane in order to improve their dispersion state and stability in paraffin wax. A family of paraffin-based phase change material (PCM) composites filled with MWCNTs was prepared with different loadings (0, 0.1, 0.5, and 1 wt%) of pristine MWCNTs and organo-silane modified MWCNTs (Si-MWCNT). Structural analyses were performed by means of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and rheological studies using temperature sweeps. Moreover, phase change transition temperatures and heat of fusion as well as thermal and electrical conductivities of the developed PCM nanocomposites were determined. The SEM micrographs and FTIR absorption bands appearing at approximately 1038 and 1112 cm⁻¹ confirmed the silane modification. Differential scanning calorimetery (DSC) results indicate that the presence of Si-MWCNTs leads to slightly favorable enhancement in the energy storage capacity at the maximum loading. It was also shown that the thermal conductivity of the PCM nanocomposites, in both solid and liquid phases, increased with increasing the MWCNT content independent of the kind of MWCNTs by up to about 30% at the maximum loading of MWCNTs. In addition, the modification of MWCNTs made the samples completely electrically nonconductive, and the electrical surface resistivity of the PCMs containing pristine MWCNTs decreased with increasing MWCNTs loading. Furthermore, the rheological assessment under consecutive cyclic phase change demonstrated that the samples containing modified MWCNTs are more stable compared to the PCM containing pristine MWCNTs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48428.     

In situ polymerization,thermal, damping,and mechanical properties of multiwalled carbon nanotubes/polyisobutylene‐based polyurethane nanocomposites

Despite the development of strong, durable, and cost efficient polyisobutylene‐based polyurethane (PIB‐based PU) materials has yet to be achieved. The well dispersion and maximum interfacial interaction between the nanofiller and the PIB‐based PU at low loading have been scarcely studied. Here, the preparation of PIB‐based PU nanocomposites with Multiwalled carbon nanotubes (MWCNTs) using a simple in situ polymerization method is reported. The thermogravimetric analysis tests show that MWCNTs significantly improved the thermal stability of MWCNTs/PIB‐based PU nanocomposites. Compare to the pure PIB‐based PU the onset temperature of degradation for the nanocomposite was about 20°C higher at 0.7 wt% MWCNTs loading. Efficient load transfer is found between the nanofiller MWCNTs and PIB‐based PU and the mechanical properties of the MWCNTs/PIB‐based PU nanocomposite with well dispersion are improved. A 63% improvement of Young's modulus and slightly increased of tensile strength are achieved by addition of only 0.7 wt% of MWCNTs. The experimentally determined Young's modulus is in well agreement with the theoretical simulation. It is worth noting that the PIB‐based PU and MWCNTs/PIB‐based PU nanocomposites exhibit excellent damping properties (tan δ > 0.3) from −45°C to 8°C. POLYM. COMPOS., 36:198–203, 2015. © 2014 Society of Plastics Engineers     

Influence of MWCTs and nanometal oxide/MWCTs hybrids on the thermal conduction of their acrylic-based nanocomposites

In this study, acrylic-based nanocomposites containing different contents of multi-walled carbon nanotubes (MWCNTs) and metal oxide nanoparticles (i.e., TiO₂, CuO and Fe₂O₃) were fabricated by solvent mixing method. The thermal conductivity of these samples was evaluated. The results indicated that the thermal conductivity of all fabricated samples was significantly improved even at small loading of MWCNTs. It was found that the thermal conductivity was enhanced by increase in MWCNTs content up to 5 wt%. Similarly, the metal oxide nanoparticles caused up to 75 % increment in thermal conductivity at 1.5 wt% of their loading in acrylic film. Contrary to expectations, the thermal conductivity of acrylic film was more increased by nanometal oxides (i.e., TiO₂, CuO and Fe₂O₃) than MWCNTs. The effect of hybridizing of nanometal oxide particles (1.5 wt%) and MWCNTs (1.5 wt%) on thermal conduction was investigated as well. It was found that hybridizing improved thermal conductivities by about 85, 94 and 97 % for Fe₂O₃, TiO₂ and CuO, respectively. Finally, the effects of TiO₂ pigment and CaCO₃ extender on the thermal conductivity of acrylic polymer and nano-TiO₂ acrylic composites were studied. It was found that TiO₂ could increase considerably thermal conduction of its acrylic films and acrylic nanocomposites.     

Rheology and biodegradation of polylactide/silica nanocomposites

Silica‐filled polylactide (PLA) nanocomposites were prepared by melt compounding. The oscillatory rheological properties and biodegradation behavior were then investigated. As the silica loadings reach up to 5 wt%, percolated silica network structures form. For the percolated PLA/silica nanocomposites sample (the silica content was >5 wt%), the modulus enhances with an increase of temperature evidently. Moreover, it is interesting to find that the biodegradation rates have been enhanced obviously in the PLA/silica nanocomposites than in neat PLA. The erosion mechanism of neat PLA and the PLA/silica nanocomposites was further discussed. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Effects of multiwall carbon nanotubes on the thermal and mechanical properties of medium density polyethylene matrix nanocomposites produced by a mechanical milling method

Medium‐density polyethylene/multiwall carbon nanotube (MDPE/MWCNT) nanocomposites were produced by a mechanical milling method using a high‐energy ball mill. The MDPE and MWCNTs were added to the ball mill at a constant 20:1 weight ratio of ball/powders and milled for 10 h to obtain polyethylene matrix nanocomposites reinforced with 0.5, 1, 2.5, and 5 weight percent of MWCNTs. To clarify the role of both MWCNT content and milling time on the morphology of MDPE, some nanocomposite samples were investigated by using a scanning electron microscope. To evaluate the role of milling on the microstructure of the nanocomposites, very thin films of MDPE/MWCNTs were prepared and studied by transmission electron microscopy. Thermal behavior of these nanocomposites was investigated by using differential scanning calorimetry (DSC). Standard tensile samples were produced by compression molding. The dependence of the tensile properties of MDPE on both milling time and MWCNT content was studied by using a tensile test. The results of the microscopic evaluations showed that the milling process could be a suitable method for producing MDPE/MWCNT nanocomposites. The addition of carbon nanotubes to MDPE caused a change in its morphology at constant milling parameters. The results of the DSC tests showed that the crystallization temperature of MDPE increased as MWCNTs were added, although no dependency was observed as milling time increased. Crystallization index changed from 50 to 55% as MWCNT content increased from 0 to 5%. The results of the tensile tests showed that both the Young's modulus and the yield strength of MDPE increased as MWCNTs were added. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers