Structure‐property relationship of substituted pyrrolidine functionalized CNT epoxy nanocomposite

Carbon nanotubes (CNTs) based polymer nanocomposites hold the promise of delivering exceptional mechanical properties and multifunctional characteristics. However, the realization of exceptional properties of CNT based nanocomposites is dependent on CNT dispersion and CNT‐matrix adhesion. To this end, we modified MWCNTs by Prato reaction to yield aromatic (phenyl and 2‐hydroxy‐4‐methoxyphenyl) substituted pyrrolidine functionalized CNTs (fCNT1 and fCNT2) and aliphatic (2‐ethylbutyl and n‐octyl) substituted pyrrolidine functionalized CNTs (fCNT3 and fCNT4). The functionalization of CNTs was established by Thermogravimetric analysis (TGA), Raman Spectroscopy, and XPS techniques. Optical micrographs of fCNT epoxy mixture showed smaller aggregates compared to pristine CNT epoxy mixture. A comparison of the tensile results and onset decomposition temperature of fCNT/epoxy nanocomposite showed that aliphatic substituted pyrrolidine fCNT epoxy nanocomposites have higher onset decomposition temperature and higher tensile toughness than aromatic substituted pyrrolidine fCNT epoxy nanocomposites, which is consistent with the dispersion results of fCNTs in the epoxy matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42284.     

Wear properties of 3‐aminopropyltriethoxysilane‐functionalized carbon nanotubes reinforced ultra high molecular weight polyethylene nanocomposites

Ultra high molecular weight polyethylene (UHMWPE) is extensively used as a material in various high‐end applications with superior mechanical properties. Carbon nanotubes (CNTs) reinforced UHMWPE (CNT/UHMWPE) nanocomposite is a promising material that can compensate for the weak durability of UHMWPE. In this study, multiwalled carbon nanotubes were oxidized and silanized using acid mixture and 3‐aminopropyltriethoxysilane, respectively, to improve the interfacial strength between CNTs and UHMWPE. The CNT/UHMWPE nanocomposite was fabricated using these oxidized and silanized CNTs. The treatment effect of CNTs on the wear behavior of the CNT/UHMWPE nanocomposites was investigated through wear tests. The oxidization and silanization of CNTs were confirmed by infrared spectroscopy. Scanning electron microscope analysis showed that the silane‐treated CNT/UHMWPE nanocomposites showed better dispersion and interfacial adhesion between UHMWPE and CNTs becaue of the newly formed functional groups on the CNTs. The friction coefficient and wear rate of silanized CNT/UHMWPE nanocomposite were also found to be lower than those of raw UHMWPE and oxidized CNT/UHMWPE nanocomposite. CNTs were functionalized using oxidation and silanization methods to improve the interfacial adhesion between CNTs and UHMWPE. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Surfactant‐assisted processing of polyimide/multiwall carbon nanotube nanocomposites for microelectronics applications

The dispersion and stability of carbon nanotubes (CNTs) inside a polymer matrix, especially with a high CNT content, are still big challenges. Moreover, the interaction between CNTs and the polymer matrix should be strong enough to improve the mechanical properties. The efficient dispersion of CNTs is essential for the formation of a uniform distribution of a CNT network in a polymer composite. Polyimide/multiwall CNT nanocomposites were synthesized by in situ polymerization with the aid of a surfactant. A Fourier transform infrared spectroscopy study proved that the surfactant did not hamper the polymerization of the polyimide. The microstructure, storage modulus and electrical conductivity of the nanocomposites were improved using a particular amount of the surfactant. Environmental stability test results showed that the polyimide with 1 wt% of CNTs produced with the aid of the surfactant possessed excellent reliability in high‐temperature and high‐humidity environments. Surfactants were successfully used to obtain fine‐structure polyimide/CNT nanocomposites by in situ polymerization. The enhancement of the mechanical properties was attributed to the incorporation of the surfactant. A percolation of electrical conductivity could be achieved with 1 wt% of CNTs. Copyright © 2010 Society of Chemical Industry     

Tailoring in thermomechanical properties of ethylene propylene diene monomer elastomer with silane functionalized multiwalled carbon nanotubes

The incorporation of silane treated multiwalled carbon nanotubes (S‐MWCNTs) is used as an effective path for tailoring thermomechanical properties of ethylene propylene diene monomer (EPDM). In this study, S‐MWCNTs were introduced into EPDM using internal dispersion kneader and two roller mixing mill. By altering the mass ratio of S‐MWCNTs from 0 to 1, thermal conductivity, thermal stability and phase transition temperatures and their respective enthalpies are discussed of the fabricated nanocomposites. It is observed that silane modification improves their dispersion and increases the interfacial bonding between MWCNTs and polymer matrix. Scanning electron microscopy along energy dispersive spectroscopy analysis is performed to confirm the silane functionalized MWCNTs are selectively distributed in the host polymer. More importantly, an important increase in mechanical properties like ultimate tensile strength and hardness is achieved through introducing silane functionalized MWCNTs. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43221.     

In situ preparation of polyimide/amino‐functionalized carbon nanotube composites and their properties

In order to improve the dispersion of carbon nanotubes (CNTs) in polyimide (PI) matrix and the interfacial interaction between CNTs and PI, 4,4′‐diaminodiphenyl ether (ODA)‐functionalized carbon nanotubes (CNTs‐ODA) were synthesized by oxidation and amidation reactions. The structures and morphologies of CNTs‐ODA were characterized using Fourier transform infrared spectrometer, transmission electron microscopy, and thermal gravimetric analysis. Then a series of polyimide/amino‐functionalized carbon nanotube (PI/CNT‐ODA) nanocomposites were prepared by in situ polymerization. CNTs‐ODA were homogeneously dispersed in PI matrix. The influence of CNT‐ODA content on mechanical properties of PI/CNT‐ODA nanocomposites was investigated. It was found that the mechanical properties of nanocomposites were enhanced with the increase in CNT‐ODA loading. When the content of CNTs‐ODA was 3 wt%, the tensile strength of PI/CNT‐ODA nanocomposites was up to 169.07 MPa (87.11% higher than that of neat PI). The modulus of PI/CNTs‐ODA was increased by 62.64%, while elongation at break was increased by 66.05%. The improvement of the mechanical properties of PI/CNT‐ODA nanocomposites were due to the strong chemical bond and interfacial interaction between CNTs‐ODA and PI matrix. POLYM. COMPOS., 35:1952–1959, 2014. © 2014 Society of Plastics Engineers     

Impact of injection‐molding processing parameters on the electrical,mechanical, and thermal properties of thermoplastic/carbon nanotube nanocomposites

Thermoplastic nanocomposites, based on high‐density polyethylene, polyamide 6, polyamide 66, poly(butylene terephthalate), or polycarbonate and containing multiwalled carbon nanotubes (CNTs), were compounded with either neat CNTs or commercial CNT master batches and injection‐molded for the evaluation of their electrical, mechanical, and thermal properties. The nanocomposites reached a percolation threshold within CNT concentrations of 2–5 wt %; however, the mechanical properties of the host polymers were affected. For some nanocomposites, better properties were achieved with neat CNTs, whereas for others, master batches were better. Then, polycarbonate and poly(butylene terephthalate), both with a CNT concentration of 3 wt %, were injection‐molded with a screening design of experiments (DOE) to evaluate the effects of the processing parameters on the properties of the nanocomposites. Although only a 10‐run screening DOE was performed, such effects were clearly observed. The volume resistivity was significantly dependent on the working temperature and varied up to 4 orders of magnitude. Other properties were also dependent on the processing parameters, albeit in a less pronounced fashion. Transmission electron microscopy indicated that conductive samples formed a percolation network, whereas nonconductive samples did not. In conclusion, injection‐molding parameters have a significant impact on the properties of polymer/CNT nanocomposites, and these parameters should be optimized to yield the best results. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Modifying montmorillonite clay via silane grafting and interfacial polycondensation for melt compounding of nylon‐66 nanocomposite

A trifunctional organo alkoxysilane (3‐aminopropyl)triethoxysilane (γ‐APS) has been used as reagent for the chemical modification of montmorillonite clay. Silane grafting was taken place in dry and hydrolyzing conditions. Silane grafted and pristine clay took part in interfacial polycondensation process to deposit a layer of nylon‐66 onto the clay lamellae and therefore, enhance their affinity with nylon‐66 matrix. Evidence of presence of grafted silane molecules and deposition of nylon‐66 on clay particles were provided by Fourier transform‐infrared, thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). Such modified clays and pristine clays were melt compounded with nylon‐66. The structures of the resulting nylon composites were characterized using XRD and transmission electron microscopy and the results showed presence of both intercalation and exfoliation. TGA thermograms of nanocomposites indicated improved thermal stability upon the incorporation of silane grafted montmorillonite. Furthermore, differential scanning calorimetry scans showed that silane modified clays promoted crystallization in nanocomposites. Increase of storage modulus and depression of tan δ peak in nanocomposites in dynamical mechanical thermal analysis were observed. The rheological properties of nylon‐66 and nanocomposites were also evaluated and differences in values of complex viscosity of samples were noticed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Aramid–multiwalled carbon nanotube nanocomposites: effect of compatibilization through oligomer wrapping of the nanotubes

Aramid–multiwalled carbon nanotube (MWCNT) nanocomposites with different CNT loadings were prepared by the solution‐blending technique. Aramid oligomeric chains having reactive amine end‐groups were covalently grafted and wrapped over the surface of acid‐functionalized MWCNTs. The presence of functional groups and surface modification of MWCNTs were studied using Raman, Fourier transform infrared and X‐ray photoelectron spectroscopic and transmission/scanning electron microscopic techniques. Addition of these MWCNTs resulted in a homogeneous dispersion throughout the aramid matrix. Dynamic mechanical thermal analysis showed an increase in the storage modulus and the glass transition temperature involved with α‐relaxations on CNT loading. The coefficient of thermal expansion (CTE) of aramid was reduced on loading with such CNTs. Strong interfacial interactions of the matrix with the surface‐modified CNTs reduced the stress‐transfer problem in the composite material and resulted in higher modulus of 4.26 GPa and a glass transition temperature of 338.5 °C, whereas the CTE was reduced to 101.8 ppm °C^?1 on addition of only 2.5 wt% CNTs in the aramid matrix. © 2016 Society of Chemical Industry     

Thermal and electrical properties of carbon nanotubes based polysulfone nanocomposites

Carbon nanotubes (CNTs)-reinforced polysulfone (PSU) nanocomposites were prepared through solution mixing of PSU and different weight percent of multi-walled carbon nanotubes (MWCNTs). Thermal properties of nanocomposites were characterized using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA studies revealed an increase in thermal stability of the PSU/MWCNTs nanocomposites, which is due to the hindrance of the nanodispered carbon nanotubes to the thermal transfer in nanocomposites and also due to higher thermal stability of CNTs. Morphological properties of nanocomposites were characterized by high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscope (FESEM). The influence of CNTs loading on electrical properties of PSU/MWCNTs nanocomposites was studied by the measurement of AC and DC resistivity. Dielectric study of nanocomposites was carried out at different frequencies (10 Hz–1 MHz) by using LCR meter. An increase in dielectric constant and dielectric loss was observed with increase in CNTs content, which is due to the interfacial polarization between conducting CNTs and PSU.     

Silane grafting reactions of LDPE,HDPE, and LLDPE

Vinyl trimethoxysilane and vinyl triethoxysilane grafting reactions, induced by dicumyl peroxide, of LDPE, HDPE, and LLDPE were investigated. The apparent activation energy of vinyl trimethoxysilane grafting reactions was positive when the reactions were induced by 0.2 phr of the peroxide. The apparent activation energies were negative when 0.05, 0.1, 0.15, and 0.25 phr of peroxide were used. The extents of vinyl trimethoxysilane grafting reactions of polyethylenes were in the order of LLDPE > LDPE > HDPE, although the extents of peroxide cross‐linking were in the order of LDPE > LLDPE > HDPE. As compared with vinyl trimethoxysilane, vinyl triethoxysilane produced a relatively high extent of grafting reactions of LDPE but showed a relatively low rate of water cross‐linking reactions of the silane‐grafted LDPE. The investigation of effects of the amount of peroxide on the vinyl trimethoxysilane grafting reaction heats demonstrated that the extent of silane grafting reactions increased proportionally as peroxide was increased until a certain amount (the value was dependent on the amount of silane used). Beyond this amount of peroxide, the silane grafting did not increase, whereas the peroxide cross‐linking appeared to increase significantly with increasing amounts of peroxide. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3404–3411, 1999     

Interfacial adhesion and water resistance of stainless steel–polyolefin improved by functionalized silane

The adhesion strength and water resistance of stainless steel and adhesive resin composites determine the long‐term performance of wires and cables; however, adhesion at stainless steel interfaces is difficult. Herein, we prepared ethylene acrylic acid/linear low‐density polyethylene (EAA/LLDPE) blends with good mechanical and adhesive properties. Silane was anchored to the surface of stainless steel. The effects of silane functionalization on the adhesion surface were investigated by X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The reaction mechanism between the stainless steel, silane, and EAA/LLDPE revealed adhesion was optimized when a 3:7 volume ratio of 3‐methacryloxypropyltrimethoxysilane (MEMO): 3‐aminopropyltrimethoxysilane (A‐1110) was used to modify the stainless steel substrate. SEM images of EAA/LLDPE film peel surfaces found the silane‐treated stainless steel substrates produced rough surfaces with a uniform void indicating the silane treatment enhanced the stainless steel and EAA/LLDPE film interaction. The stainless steel and EAA/LLDPE film adhesion and water resistance improved and the peel strength after water resistance testing at 68°C for 168 h increased from 3.18 N/cm to 9.37 N/cm compared to untreated stainless steel. Silane‐modified stainless steel and EAA/LLDPE blend film composite materials demonstrate potential for application in wires and cables used in environmental corrosion‐resistant applications. POLYM. ENG. SCI., 59:1866–1873, 2019. © 2019 Society of Plastics Engineers     

Effect of phenol functionalization of carbon nanotubes on properties of natural rubber nanocomposites

This paper reports the results of studies on the effect of phenol functionalization of carbon nanotubes (CNTs) on the mechanical and dynamic mechanical properties of natural rubber (NR) composites. Fourier transform infrared spectrometry (FTIR) indicates characteristic peaks for ether and aromatic rings in the case of phenol functionalized CNT. Although differential scanning calorimetric (DSC) studies show no changes in the glass‐rubber transition temperature (T_g) of NR in the nanocomposites due to surface modification of CNT, dynamic mechanical studies show marginal shifting of T_g to higher temperature, the effect being pronounced in the case of functionalized CNT. Stress‐strain plots suggest an optimum loading of 5 phr CNT in NR formulations and the phenolic functionalization of CNT does not affect significantly the stress‐strain properties of the NR nanocomposites. The storage moduli register an increase in the presence of CNT and this increase is greater in the case of functionalized CNT. Loss tangent showed a decrease in the presence of CNT, and the effect is more pronounced in the case of phenol functionalized CNT. Transmission electron microscopy (TEM) reveals that phenol functionalization causes improvement in dispersion of CNT in NR matrix. This is corroborated by the increase in electrical resistivity in the case of phenol functionalized CNT/NR composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Physical properties of phenol-anchored multiwall carbon nanotube/epoxy nanocomposite

Surface functionalization of multiwall carbon nanotubes (MWCNTs) was carried out by introducing a ylide group containing anchored phenol structures. Epoxy nanocomposites filled with modified and pristine carbon nanotubes were prepared, and their mechanical, electrical, and thermal properties were evaluated. Mechanical properties such as tensile strengths and Young’s moduli of the epoxy nanocomposites increased significantly with the addition of the modified MWCNTs compared to the pristine MWCNTs, due to the strong interaction between the modified MWCNTs and the epoxy matrix. Scanning electron microscopy of the fractured epoxy systems revealed that the functionalized MWCNTs were finely dispersed in the matrix, as opposed to the pristine carbon nanotubes. The epoxy/functionalized MWCNT nanocomposite had a lower surface electrical resistance than the epoxy/pristine MWCNT nanocomposite, confirming the effect of functionalization.     

Synthesis and characterization of multiwall carbon nanotube/waterborne polyurethane nanocomposites

The preparation of thermoplastic nanocomposites of waterborne polyurethane (WBPU) and multiwall carbon nanotubes (MWCNTs) via an in situ polymerization approach is presented. The effects of the presence and content of MWCNTs on the morphology and thermal, mechanical and electrical properties of the nanocomposites were investigated. Carbon nanotubes were modified with amide groups in order to enhance their chemical affinity towards WBPU. Thermogravimetric studies show enhanced thermal stability of the nanocomposites. Scanning and transmission electronic microscopy images prove that functionalized carbon nanotubes can be effectively dispersed in WBPU matrix. Mechanical properties reveal that Young's modulus and tensile strength tend to increase when appropriate amounts of MWCNTs are loaded due to the reinforcing effect of the functionalized carbon nanotubes. Thermal properties show an increase in the glass transition temperature and storage modulus with an increase in MWCNT content. X‐ray diffraction reveals better crystallization of the WBPU in the presence of MWCNTs. The WBPU/MWCNT nanocomposite film containing 1 wt% of MWCNTs exhibits a conductivity nearly five orders of magnitude higher than that of WBPU film. © 2017 Society of Chemical Industry     

Effect of Graphene and Carbon Nanotube on Low‐Density Polyethylene Nanocomposites

The nanocomposites of low‐density polyethylene contain graphene (LDPE/Gr) and low‐density polyethylene contains carbon‐nanotubes (LDPE/CNTs) with different Gr loadings (0.5, 1, and 3 wt%) were formulated with a melt‐mixing method. The distribution of Grs in LDPE was detected by scanning electron microscopy. In this study, morphological, electrical, thermal, tensile, and rheological properties of nanocomposites were comparatively investigated. The outcomes were reviewed and it was recognized that LDPE/Gr nanocomposites reveal superior properties than LDPE/CNTs nanocomposites at the same loadings. The superior performance of LDPE/Gr nanocomposites attributes to the large aspect ratio of Gr and its two dimensional flat surfaces which effect in increasing physical interlinking with LDPE chains and expanded the interface zone at filler–LDPE interface. It was also identified that the achieved results for LDPE/CNT nanocomposites, which has a compact surface area and linkage with LDPE, are less noticeable than similar Gr compounds due to higher interfacial interactions between Gr and LDPE. The thermomechanical results of LDPE/Gr nanocomposites have been studied and the influence of nanoscaled strengthening in the thermoplastic matrix has been investigated. The existence of Gr limits the flexibility of LDPE chains, increases the rigidity and the strength of the LDPE‐nanocomposites. This study compares how a flat or roll structure of carbon nano‐structure additive (Grs vs. CNTs) can change the various properties of LDPE nanocomposites. J. VINYL ADDIT. TECHNOL., 25:35–40, 2019. © 2018 Society of Plastics Engineers     

Electrical and mechanical behaviors of carbon nanotube‐filled polymer blends

Four carbon nanotube (CNT)‐filled polymer blends, i.e., CNT‐filled polyethylene terephthalate (PET)/polyvinylidene fluoride, PET/nylon 6,6, PET/polypropylene, and PET/high‐density polyethylene blends, have been injection‐molded and characterized in terms of their microstructures, electrical conductivities, and mechanical properties. The distribution of CNTs in the polymer blends has been examined based on their wetting coefficients and minimization of the interfacial energy. The electrical conductivity and mechanical properties have been related to the cocontinuous polymer blends, the conductive path formed by CNTs, the CNT distribution, and the intrinsic properties of the constituent polymers. It is found that to obtain a CNT‐filled polymer composite with both high electrical conductivity and good mechanical properties, it is preferred that most CNTs distribute in one polymer phase, while the other polymer phase(s) remain neat. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 477–488, 2006     

Structural,thermal, and gas transport properties of HDPE/LLDPE blend‐based nanocomposites using a mixture of HDPE‐g‐MA and LLDPE‐g‐MA as compatibilizer

Nanocomposites based on high density polyethylene (HDPE)/linear low density polyethylene (LLDPE) blend were prepared by melt compounding in a twin‐screw extruder using organoclay (montmorillonite) as nano‐filler and a 50/50 wt% mixture of maleic anhydride functionalized high density polyethylene (HDPE‐g‐MA) and linear low density polyethylene (LLDPE‐g‐MA) as the compatibilizing system. The addition of a maleated polyethylene‐based compatibilizing system was required to improve the organoclay dispersion in the HDPE/LLDPE blend‐based nanocomposite. In this work, the relationships between thermal properties, gas transport properties, and morphology were correlated. The compatibilized nanocomposite exhibited an intercalated morphology with a small number of individual platelets dispersed in the HDPE/LLDPE matrix, leading to an significant decrease in the oxygen permeation coefficient of the nanocomposites. A decrease in the carbon dioxide permeability and oxygen permeability with increase of nanoclay was observed for the compatibilized nanocomposites. The carbon dioxide permeability of the compatibilized nanocomposites was lower than the carbon dioxide permeability of the uncompatibilized nanocomposites even with the low intrinsic barrier properties of the compatibilizer. These effects were attributed to a good dispersion of the inorganic filler, good wettability of the filler by the polymer matrix, and strong interactions at the interface that increased the tortuous path for diffusion. Theoretical permeability models were used to estimate the final aspect ratio of nanoclay in the nanocomposite and showed good agreement with the aspect ratio obtained directly from TEM images. POLYM. ENG. SCI., 56:765–775, 2016. © 2016 Society of Plastics Engineers     

Effects of in‐situ functionalization of carbon nanotubes with bis(triethoxysilylpropyl) tetrasulfide (TESPT) and 3‐aminopropyltriethoxysilane (APTES) on properties of epoxidized natural rubber–carbon nanotube composites

Composites of carbon nanotubes (CNT) and epoxidized natural rubber (ENR) were prepared by in‐situ functionalization of CNT with two alternative silane coupling agents: bis(triethoxysilylpropyl) tetrasulfide (TESPT) and 3‐aminopropyltriethoxysilane (APTES). The reactions of ENR molecules with the functional groups on CNT surfaces and with the silane molecules were characterized by Fourier transform infrared. Furthermore, cross‐link density, relaxation behaviors, curing, mechanical, electrical, and morphological properties of pristine ENR and the ENR composites were investigated. Very low percolation thresholds, at CNT concentrations as low as 1 phr, were observed in the ENR–CNT and the ENR–CNT–TESPT composites. This might be attributed to improvements in the chemical linkages between ENR molecules and functional groups on CNT surfaces that led to a homogenous dispersion of CNTs in the ENR matrix, with loose CNT agglomerates. POLYM. ENG. SCI., 55:2500–2510, 2015. © 2015 Society of Plastics Engineers     

Thermoplastic vulcanizate nanocomposites based on polyethylene/reclaimed rubber: A correlation between carbon nanotube dispersion state and electrical percolation threshold

A three-step melt blending process was utilized to produce linear low-density polyethylene (LLDPE)/reclaimed rubber (RR)/carbon nanotube (CNT) nanocomposites in the presence of maleic anhydride grafted polyethylene as a compatibilizer. The effect of LLDPE/RR ratio and CNT content on the morphological, thermal, mechanical, and rheological behavior of these dynamically vulcanized LLDPE/RR nanocomposites were investigated. The morphological study showed that the RR was dispersed in the LLDPE matrix, and CNT addition led to an improved morphology as smaller RR sizes inside LLDPE were observed. The mechanical results revealed that increasing the RR content decreased the hardness, modulus of elasticity, and elongation at break while CNT improved the tensile properties and other mechanical properties. The differential scanning calorimeter analysis showed that the CNT improved the LLDPE crystallization by acting as nucleation agents. Dynamic mechanical analysis showed higher storage modulus and lower loss factor as compared to the neat blend due to mobility restrictions of the polymer chains induced by the presence of CNT. For the conditions studied, the electrical percolation threshold was found to occur at a very low CNT concentration (about 1 wt %) compared to the literature because of the specific structure produced leading to CNT residing in the LLDPE matrix and at the interface between both polymeric phases. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47795.     

The effect of carbon nanotube agglomeration on the thermal and mechanical properties of polyethylene oxide

The effects of agglomerated versus deagglomerated multiwalled carbon nanotubes on the thermal and mechanical characteristics of polyethylene oxide were studied. The specimens were prepared via solution‐sonication method, using two procedures. In the first procedure, CNT‐PEO solutions were prepared with as‐received MWCNTs, before sonication using an ultrasonic bath; in the second procedure, aggregated MWCNTs were first deagglomerated using high‐intensity ultrasonic processor, before mixing with the PEO. The two solution preparation procedures did result in significant thermal property differences such as increased transition temperature and crystallinity, but only one mechanical property can be conclusively associated with the sample preparation method—the breaking strain which was marginally higher for nanocomposites containing deagglomerated CNTs, although in all cases the breaking strains were much lower for nanocomposites than for unfilled polymer. However, the overall results confirm the effectiveness of CNTs both as nucleation agents for semicrystalline polymers, and as fillers for enhancement of mechanical properties of the matrix polymer. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers