scholarly journals Evaluation of the role of carbon nanotubes on the electrical properties of poly(butylene terephthalate) nanocomposites for industrial applications

2018 ◽  
Vol 51 (1) ◽  
pp. 3-25 ◽  
Author(s):  
A Dorigato ◽  
V Freitas ◽  
JA Covas ◽  
MC Paiva ◽  
M Brugnara ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Conductive Polymer ◽  
Melt Flow Index ◽  
Industrial Applications ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Electrically Conductive ◽  
Joule Effect ◽  
Butylene Terephthalate

In this article, innovative electrically conductive polymer nanocomposites based on poly(butylene terephthalate) (PBT) filled with carbon nanotubes (CNTs) at different concentrations, to be used in the automotive field, have been investigated. Field emission scanning electron microscopy (FESEM) analysis revealed how a good nanofiller dispersion was obtained, especially by using surface treated nanotubes and by processing these materials using a more restrictive screw configuration. Melt flow index measurements highlighted that the processability of these nanocomposites was reduced at elevated filler amounts, even if CNT surface treatment promoted a partial retention of the fluidity of the neat PBT. Thermal degradation stability was improved upon the addition of CNT, even at limited filler amounts. Differential scanning calorimetry measurements evidenced how the presence of CNT slightly increased both the crystallization temperature and the crystalline fraction of the materials. The additivation of CNTs promoted a stiffening effect at elevated CNT contents, associated to an evident embrittlement of the samples. Electrical resistivity measurements showed that the most interesting results (i.e. 2.6 × 101 Ω·cm) were obtained for nanocomposites with a total filler content of 3 wt%, processed using the more restrictive screw configuration. For these materials, it was possible to obtain a rapid surface heating through Joule effect at applied voltages of 12 V.

scholarly journals Selection of Immiscible Polymer Blends Filled with Carbon Nanotubes for Heating Applications

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1827 ◽  
Author(s):  
Marischal ◽  
Cayla ◽  
Lemort ◽  
Campagne ◽  
Devaux
Keyword(s):  
Carbon Nanotubes ◽  
Melt Spinning ◽  
Filler Content ◽  
Conductive Polymer ◽  
Polyamide 6 ◽  
Electrically Conductive ◽  
Joule Effect ◽  
Immiscible Blends ◽  
Selective Localization ◽  
Application Fields

In many application fields, such as medicine or sports, heating textiles use electrically conductive multifilaments. This multifilament can be developed from conductive polymer composites (CPC), which are blends of an insulating polymer filled with electrically conductive particles. However, this multifilament must have filler content above the percolation threshold, which leads to an increase of the viscosity and problems during the melt spinning process. Immiscible blends between two polymers (one being a CPC) can be used to allow the reduction of the global filler content if each polymer is co-continuous with a selective localization of the fillers in only one polymer. In this study, three immiscible blends were developed between polypropylene, polyethylene terephthalate, or polyamide 6 and a filled polycaprolactone with carbon nanotubes. The morphology of each blend at different ratios was studied using models of co-continuity and prediction of fillers localization according to viscosity, interfacial energy, elastic modulus, and loss factor of each polymer. This theoretical approach was compared to experimental values to find out differences between methods. The electrical properties (electrical conductivity and Joule effect) were also studied. The co-continuity, the selective localization in the polycaprolactone, and the Joule effect were only exhibited by the polypropylene/filled polycaprolactone 50/50 wt.%.

scholarly journals Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 390
Author(s):  
Fernando Luiz Lavoie ◽  
Marcelo Kobelnik ◽  
Clever Aparecido Valentin ◽  
Érica Fernanda da Silva Tirelli ◽  
Maria de Lurdes Lopes ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Morphological Changes ◽  
Field Performance ◽  
Melt Flow Index ◽  
Flow Index ◽  
Test Results ◽  
Upward Trend ◽  
Scanning Calorimetry ◽  
Ultraviolet Exposure ◽  
Brittle Behavior

High-density polyethylene (HDPE) geomembranes are polymeric geosynthetic materials usually applied as a liner in environmental facilities due to their good mechanical properties, good welding conditions, and excellent chemical resistance. A geomembrane’s field performance is affected by different conditions and exposures, including ultraviolet radiation, thermal and oxidative exposure, and chemical contact. This article presents an experimental study with a 1.0 mm-thick HDPE virgin geomembrane exposed by the Xenon arc weatherometer for 2160 h and the ultraviolet fluorescent weatherometer for 8760 h to understand the geomembrane’s behavior under ultraviolet exposure. The evaluation was performed using the melt flow index (MFI) test, oxidative-induction time (OIT) tests, tensile test, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. The sample exposed in the Xenon arc equipment showed a tendency to increase the MFI values during the exposure time. This upward trend may indicate morphological changes in the polymer. The tensile behavior analysis showed a tendency of the sample to lose ductility, without showing brittle behavior. The samples’ OIT test results under both device exposures showed faster antioxidant depletion for the standard OIT test than the high-pressure OIT test. The DSC and FTIR analyses did not demonstrate the polymer’s changes.

scholarly journals Halloysite Nanotubes and Silane-Treated Alumina Trihydrate Hybrid Flame Retardant System for High-Performance Cable Insulation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2134
Author(s):  
Sandra Paszkiewicz ◽  
Izabela Irska ◽  
Iman Taraghi ◽  
Elżbieta Piesowicz ◽  
Jakub Sieminski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Blend ◽  
Hybrid System ◽  
Reference Sample ◽  
Melt Flow Index ◽  
Halloysite Nanotubes ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index ◽  
Alumina Trihydrate

The effect of the presence of halloysite nanotubes (HNTs) and silane-treated alumina trihydrate (ATH-sil) nanofillers on the mechanical, thermal, and flame retardancy properties of ethylene-vinyl acetate (EVA) copolymer/low-density polyethylene (LDPE) blends was investigated. Different weight percentages of HNT and ATH-sil nanoparticles, as well as the hybrid system of those nanofillers, were melt mixed with the polymer blend (reference sample) using a twin-screw extruder. The morphology of the nanoparticles and polymer compositions was studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The mechanical properties, hardness, water absorption, and melt flow index (MFI) of the compositions were assessed. The tensile strength increases as a function of the amount of HNT nanofiller; however, the elongation at break decreases. In the case of the hybrid system of nanofillers, the compositions showed superior mechanical properties. The thermal properties of the reference sample and those of the corresponding sample with nanofiller blends were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Two peaks were observed in the melting and crystallization temperatures. This shows that the EVA/LDPE is an immiscible polymer blend. The thermal stability of the blends was improved by the presence of HNTs and ATH-sil nanoparticles. Thermal degradation temperatures were shifted to higher values by the presence of hybrid nanofillers. Finally, the flammability of the compositions was assessed. Flammability as reflected by the limiting oxygen index (OI) was increased by the presence of HNT and ATH-sil nanofiller and a hybrid system of the nanoparticles.

scholarly journals Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1242
Author(s):  
Olga Mysiukiewicz ◽  
Paulina Kosmela ◽  
Mateusz Barczewski ◽  
Aleksander Hejna
Keyword(s):  
Mechanical Properties ◽  
Melt Flow Index ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Metal Composites ◽  
Pre Treatment ◽  
The Impact ◽  
Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

THE PROSPECTS OF USING CARBON NANOTUBES TO IMPART FUNCTIONAL PROPERTIES TO THE SURFACE OF POLYMER MATERIALS (review)

2021 ◽  
pp. 11-21
Author(s):  
L.V. Solovyanchik ◽  
◽  
S.V. Kondrashov ◽  
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Functional Properties ◽  
Scientific Literature ◽  
Conductive Polymer ◽  
Polymer Materials ◽  
Mechanism Of Formation ◽  
Electrically Conductive ◽  
Structured Surface

Presents a review of the scientific literature on various methods for producing electrically conductive polymer materials and coatings. The prospects of using carbon nanotubes (CNT) to impart high electrical properties to the surface of materials are shown. The mechanism of formation of the structured surface of polymer materials with CNT is described. It is shown that the use of CNT is a promising way to impart electrically conductive and superhydrophobic properties to the surface.

Characterization of microwave-treated oil palm empty fruit bunch/glass fibre/polypropylene composites

2015 ◽  
Vol 30 (7) ◽  
pp. 986-1002 ◽  
Author(s):  
MR Islam ◽  
A Gupta ◽  
M Rivai ◽  
MDH Beg
Keyword(s):  
Glass Fibre ◽  
Oil Palm ◽  
Melt Flow Index ◽  
Flow Index ◽  
Mechanical And Thermal Properties ◽  
Empty Fruit Bunch ◽  
Scanning Calorimetry ◽  
Fixed Temperature ◽  
Polypropylene Composites ◽  
Degradation Temperature

Composites were prepared from recycled polypropylene (RPP), oil palm empty fruit bunch (EFB) and/or glass fibre (GF) using extrusion and injection moulding techniques. Two types of maleic anhydride-grafted polypropylene such as Polybond 3200 and Fusabond P 613 were used to improve the interfacial adhesion between fibres and matrix. The EFB: GF ratio was fixed as 70:30 and fibre loading was considered as 40 wt%. Microwave was used to treat the EFB fibre, which was soaked in a fixed mass concentration (12.5%) of alkali solution at different temperatures (70, 80 and 90°C) for a fixed period of time (60 min) and for different times (60, 90 and 120 min) at a fixed temperature (90°C). A magnetron controller was developed to control the time and temperature accurately for the treatment of fibre. Various characterization techniques such as density, melt flow index, tensile, Izod impact, flexural, field-emission scanning electron microscopy and water uptake testing were performed for the composites. Besides, thermogravimetric analysis and differential scanning calorimetry were also used to evaluate the thermal and crystalline properties of the composites, respectively. Result analyses revealed that microwave-treated fibre-based composites showed improved mechanical and thermal properties. EFB fibres treated at 90°C for 90 min were found to be suitable for better reinforcement into the composite in terms of mechanical, thermal and crystalline properties. Moreover, onset degradation temperature and water absorption properties were also found to be changed apparently due to treatment.

scholarly journals Biological activity of carbon nanoparticles produced in combustion process

2019 ◽  
Vol 179 (4) ◽  
pp. 269-273
Author(s):  
Jarosław KAŁUŻNY ◽  
Natalia IDASZEWSKA ◽  
Tomasz RUNKA ◽  
Adam PIASECKI ◽  
Marek NOWICKI ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Experimental Study ◽  
Carbon Nanoparticles ◽  
Dominant Role ◽  
Combustion Process ◽  
Industrial Applications ◽  
Carbon Allotropes ◽  
Air Purifier ◽  
Residential Space

In the recent years industrial applications of carbon allotropes such as carbon nanotubes (CNTs) and graphene have been tested extensively, thus justifying research on the environmental impact these materials have. In the current paper we compare EDS spectroscopy results of a cabin filter used in a car to a filter used in an air purifier inside a residential space. The contaminants adsorbed on the carbon nanoparticles trapped in both types of filters allows for determining of their source of origin demonstrating clearly the dominant role of non-road emissions in Poland. Finally we present the experimental study on the growth of plants on substrates intentionally enriched with CNTs.

Melt Processed Polymer Blends for Potential Regenerative Medicine Applications

2014 ◽  
Vol 679 ◽  
pp. 92-100
Author(s):  
Elaine Kenny ◽  
Declan M. Devine ◽  
Clement L. Higginbotham ◽  
Luke M. Geever
Keyword(s):  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Regenerative Medicine ◽  
Polyethylene Oxide ◽  
Melt Flow Index ◽  
Flow Index ◽  
Biodegradable Implants ◽  
Scanning Calorimetry ◽  
Breakdown Rate

There is an urgent and unmet requirement for biocompatible and biodegradable implants that gradually resorb when implanted in vivo. This study examines the potential of melt extruded thermoplastics polyethylene oxide (PEO) and polycaprolactone (PCL) in the area of regenerative medicine. Various ratios of PEO and PCL were melt blended and analysed in order to obtain an optimised breakdown rate. Subsequently the effect of varying the molecular weight of PCL using a constant molecular weight PEO was also examined. Samples were characterised using melt flow index (MFI), differential scanning calorimetry (DSC) and breakdown analysis. It was found that by altering both the concentrations of PEO/PCL and the molecular weight of PCL, melt viscosity, breakdown rate and thermal properties could be modulated to produce potential implant materials with a tailored breakdown rate.

Thermomechanical investigations of PEKK-HAp-CS composites

2019 ◽  
Vol 233 (11) ◽  
pp. 1196-1203
Author(s):  
Rupinder Singh ◽  
Gurchetan Singh ◽  
Jaskaran Singh ◽  
Ranvijay Kumar ◽  
Md Mustafizur Rahman ◽  
...  
Keyword(s):  
Melt Flow Index ◽  
Extrusion Process ◽  
Flow Index ◽  
Fused Deposition Modelling ◽  
Index Test ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Ether Ketone ◽  
Input Variables

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.

Tuning of HDPE Properties for 3D Printing

2018 ◽  
Vol 773 ◽  
pp. 67-71 ◽  
Author(s):  
Paweesinee Chatkunakasem ◽  
Panisa Luangjuntawong ◽  
Aphiwat Pongwisuthiruchte ◽  
Chuanchom Aumnate ◽  
Pranut Potiyaraj
Keyword(s):  
3D Printing ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Crystalline Polymers ◽  
Twin Screw ◽  
Low Crystalline

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

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